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ADDITIONS

     TO THE
           OF


XAVIER  BICHAT.
              BY P. A. BECLARD,
PROFESSOR OF ANATOMY AND PHYSIOLOGY TO THE FACULTY OF MEDICINE
                   OF PARIS, &C.
CranglateU from tfie JTrencfr
     BY GEORGE HAYWARD, M. D.
FELLOW OF THE AMERICAN ACADEMY OF ARTS AND SCIENCES,
     AND OF THE MASSACHUSETTS MEDICAL SOCIETY.
            BOSTON:
PUBLISHED BY RICHARDSON AND LORD.
       J. H. A. FROST, PRINTER.
              1823. 

/:,

              DISTRICT  OF MASSACHUSETTS,  to wit :

                                               District Clerk^s Office.
  BE IT REMEMBERED, That on  the  eighth day of January, AD. 1823, in the
forty-seventh year of the Independence of the United  States of America, llichardson &,-
Lord, of the said District, have deposited in this office the title of a book, the right whereof
they claim as proprietors, in the words following, to wit .•
  " Additions to tbe General Anatomy of Xavier Bichat.   By P. A. Beclard, Professor of
Anatomy and Physiology to the Faculty of Medicine of Paris, &c.  Translated from the
French   By George Hayward, M. D  Fellow of the American Academy of Arts and
Sciences, and of the Massachusetts Medical Society."
  In conformity to the Act of the Congress of the United States, entitled, "An Act for the
encouragement of Learning, by securing the copies of Maps, Chartsand Books to the Au-
thors and Proprietors of such Copies, during the times therein mentioned:" and also  to an
Act entitled," An Act supplementary to an Act, entitled An Act for the encouragement of
Learning, by securing the Copies of Maps, Charts and Books, to the Authors and Proprie-
tors of such Copies during the times therein mentioned ; and extending the benefits thereof
to the Arts of Designing, K.ngiaving and Etching Historical and other Prints."
                                                        JOHtf W. DAVIS,
                                       Clerk  of the  District of Massachusetts. 
NOTICE
BY THE  EDITORS OF BICHAt's  GENERAL  ANATOMY.
   WE announced in 1818 an edition of Bichat's General
 Anatomy, to which Messrs. Pinel, Beclard and  Laennec,
 were to contribute,  and we  engaged  to  give with  it as
 faithful a  portrait as possible of its  illustrious author ;
 being editors of the works of Bichat, connected  with him
 for many  years in daily relations and constantly  honoured
 with testimonials of his esteem and friendship, we owed
 this respect to his memory; but unforeseen circumstances
 have prevented  the  execution of this design by  depriving
 us of the co-operation of Messrs. Pinel and Laennec.
    M. Pinel  is  compelled to devote  to the care of his
 health the few moments that are left by his private duties ;
 and it is to  his son, the worthy inheritor of a name which
 will form an epoch in  the history of medicine, that we
 are indebted for the  notice placed at the commencement
 of this volume.
   * These Additions of Professor Beclard  were incorporated into an
 edition of Bichat's General Anatomy, which was published in Paris in
 1821; many copies however were issued in a separate form for the benefit
 of those who previously owned the works of Bichat.—Tr.
-^*  •'.•  '"* '„•- ,' ;   ', 
IV
NOTICE
  M. Laennec, after a severe disease, has been compelled
to leave the capital,  at a moment when he would  have
desired to have demonstrated all that can be drawn from
the new mode of investigation which he has made known.
  It is  then  to Professor  Beclard alone that we are in-
debted for this volume of Additions which recent works
rendered necessary  and  which  will make complete the
General Anatomy.
  M. Beclard  has laid under contribution  not  only the
writings of the French anatomists and physiologists, but
also all the important works published in Germany and
England, the  Treatises  of General Anatomy of  J. F.
Meckel, J. Gordon, the Prodromus of the great Anatomy
of Mascagni, the Hystology (description of the textures)
of  Meyer, the Table of General Anatomy of Bock, and
every thing which has appeared upon each texture in par-
ticular.  He has thought proper to add to the history ol
each system  an article upon its  morbid states, and  to de-
 vote a particular chapter  to the preternatural  textures.
 Most of the facts relative  to morbid anatomy have been
 derived from the general treatises of Morgagni, Voigtel,
 Baillie, Otto, Cruveilhier,  and a great  number of particu-
 lar treatises, among others the excellent work of M.  Laen-
 nec, who has cultivated this science with so much success.
    M. Beclard has added,  to  the interesting observations
 which his researches have furnished  him, many  which
 are peculiar to him, upon  the anatomy of man in  health
 and upon  the various alterations of the textures.
    M. Bouvier, who is ranked,  from having gained eight
 prizes from  the Faculty, among the  number  of its most 
BY THE EDITORS.
V
distinguished pupils, has assisted Professor Beclard in his
labour, who is  pleased to render justice to his  zeal and
his information.
   All the portraits of Bichat, both engravings on copper
and  lithographic  drawings,  are  far  from being resem-
blances.   The  medals of the Medical Society of Emula-
tion  and the busts even hardly recall any  of his features.
We  find them  rather in the picture of his last moments,
exhibited at the  Saloon in 1818.   M. Petroz, who  pos-
sesses it, has allowed us to consult it, and has entrusted
to us the mask in plaster moulded upon the face of Bichat
some hours after  his death.  It is by the aid of this piece,
and  the  advice of all those  who, like ourselves, have
known  him  very  particularly,  that we  have  succeeded
beyond our hopes,  since the portrait that we have had
engraved for this  edition, when viewed by those  whom
Bichat  honoured with his friendship, has recalled im-
mediately  to their minds  the great man whose remem-
brance is so dear  to them. 
V 
HISTORICAL NOTICE
              OF

XAVIER BICHAT.
   IT is  easy to enumerate  men, who, in the sciences,
have thought for themselves ; their genius opens the path
of  discovery and  the multitude follows  them.  Bichat
enjoyed  this happy privilege.  Anatomy and physiology
will always consider him among the number of those
whose works are the most fruitful in useful results, and
history will assign him  one of the first places in  that
brilliant  epoch  of  medicine  which gave so great an eclat
to the  end of the eighteenth  century.
   Xavier Bichat, born at  Thoirette, in the department
of  Ain,  on  the 11th of  November,  1771,  pursued his
classical  studies at  Lyons, and distinguished  himself
especially in rhetoric and philosophy.   He commenced
in that city the study of anatomy and surgery under Marc-
Antoine  Petit.   The political troubles  of 1793 having
soon obliged him to  remove from that unfortunate city,
he came to Paris with the intention of perfecting himself 
via              historical notice.
at the school of Desault, that he might afterwards practise
surgery in the armies.  But  soon a more brilliant and
extended path opened before him.  Having one day writ-
ten down a clinical lecture of  Desault, in the absence of
the person whose duty it was, the reading of it occasioned
the greatest sensation.  The master knew henceforth how
to appreciate the merit of the  pupil.  He offered to him
his house, treated  him as a son and associated him with
his glory and his  labours.
   Endowed with an indefatigable ardour, Bichat did  not
disappoint  the exalted hopes of his benefactor.   The
variety of his occupations was his only relaxation, and his
methodical mind and wonderful facility made him acquire
with ease  all the knowledge which is ordinarily the fruit
of long and painful study.
   Bichat  was scarcely twenty three years of age when
Desault died, (in 1795) and so  far from being overwhelm-
ed by  this unforeseen loss, it appeared to redouble his
activity.  The dressings at the Hotel-Dieu, the daily visits
to the patients, consultations,  dissections, and operations
on the dead body, had heretofore  employed all his time ;
the death  of Desault  created  for  him new occupations;
gratitude made it his duty to publish the researches and
labours of the master who had adopted him.   He wished
also then to commence his career as a teacher.
   In the winter of 1797 he gave his first course of anato-
my, and his second the  year  following.  After his duty
at the Hotel-Dieu was finished, he superintended the dis-
sections of more  than eighty pupils; he performed  nu-
merous physiological  experiments upon  living animals: 
                 historical notice.                ix
prepared for the press the surgical works of Desault, and
composed memoirs for the Medical Society of Emulation,
of which he was one  of the  founders.
   It was at this period that a revolution took place which
was to change the face  of  the science.  Professor Pinel
was the first to perceive that a  disease can  only  be an
alteration  of textures  or of organs ; that it is necessary to
study these organs and  textures,  first under  the relation
of their structure and then under that of their functions,
before we can arrive with certainty at a knowledge of
their alterations; and that thus analysis in medicine con-
sists in referring the  symptoms, the external signs of dis-
eases,  to  the  suffering  and morbid alteration of  some
organs; to study them in their seat, is to derive from the
knowledge of this seat the  indications of the treatment,
and  finally to class them according to the analogy or the
difference of the affected textures.  Such was the original
idea, which presiding over  the  execution  of the Noso-
graphie Philosophique, published in 1798, had just over-
thrown forever that  badly constructed  scaffolding raised
upon the incoherent plans  of the chemical, humoral and
mathematical  physicians, and which would  lay the  first
foundations of a true physical science.
   Bichat, struck with the description and the distinction
of the mucous and serous membranes, and especially with   /
the classification of their diseases, seized this first idea,
made new researches, and extended them to all the mem-
branes of the body; and in eighteen months after (in 1800)
he published his  Treatise upon  the Membranes, a model
of precision, originality and analytical method, which was
              2 
 X                historical notice.
 afterwards embraced in his General Anatomy, enriched
 with happy developments and new ornaments.
   It was  a  spectacle worthy the  regard  of  history, that
 noble  emulation,  frank and generous rivalship,  in this
 period of enthusiasm and  discovery, should turn every
 thing to the advantage of science.  If Bichat owed to
 Professor  Pinel the idea of his work, the latter in his turn
 drew new lights from the  researches of the young anato-
 mist,  and corrected  in the  second  edition of his Noso-
graphy the  classification  of the  diseases of the  fibrous,
 synovial and cellular systems.  This alliance of nosogra-
phy with  anatomy and physiology, this mutual exchange
 of instruction,  formed one of the characteristic traits of
this period.
   Physiology is the inseparable  companion  of anatomy ;
the structure of  the organs  is only interesting as  it leads
to researches with regard to their  functions ; thus the
Treatise upon Life and Death followed soon after the first
works  of Bichat upon Anatomy ; it  appeared the  same
year.   It is  in this work that he began to develop that
distinction of the two lives, the organic and animal, which
he has reproduced under  a thousand forms, but which
cannot be admitted, as has  been proved by Legallois,
without some  limitations.   The richness of the means
with which he pursued the development of this idea can-
not be too  much  admired.   The beautiful  experiments
that fill his Treatise, the  facts that are  made known by
them and the bold and profound  thoughts that shine in  a
great number of passages, are more than sufficient to make
us excuse some flights of a vivid and ardent  imagination. 
                  historical NOTICE.                XI
   Bichat, in his two first works, had  only thought  of
anatomy and physiology; but the circle  of his ideas en-
larging as he reflected on his subject, he ventured to leave
the beaten track, and published in the  following year his
General Anatomy, wrhich placed  the seal upon his repu-
tation, and which was translated into  almost every lan-
guage.  Before  his time, anatomy had been confined  to
the simple  description of the organs ;  he was the first
who thought himself able to rise to bolder views.   He
observed that the human body exhibits uniform, identical
systems, subjected to the same laws of growth, nutrition
and  diseases ; that these systems, everywhere present,
can be  studied in their structure as in their functions, so
as to embrace the most general results  of their organiza-
tion, and the most fruitful and useful applications.  From
that period he created a new science, General Anatomy.
He created for anatomy and physiology, a species of phi-
losophy, to which there was nothing wanting to render it
perfect, but that it should not be limited to the study of
the textures of man.   He should have extended his views
to all classes of animals, traced in them the inferiority of
the textures and organs, and  observed  the properties
which they bore  or the new functions  to which they are
called.  Comparative  anatomy and physiology would have
furnished to his lively and brilliant imagination the most
novel  views,  the most  substantial knowledge, and the
most ingenious analogies.
  It is astonishing that Bichat with that independence
of opinion which  characterized  him, should have so often
brought forward, in his General Anatomy, those old ideas, 
XI!
HISTORICAL  NOTICE.
which for two  thousand years have  continued in  the
schools, those words  vital force  and  vital properties,
abstractions which he  seems to have taken for realities, to
which he  gave a separate existence, and which  he  made
perform so important  a part in the animal economy.  Yet
for a long time past we have only recognized and we ought
to recognize but  two things in organization, structure and
functions of organ.  The philosopher should confine him-
self to the study and observation of the sensible phenom-
ena which  matter exhibits in  these two states,  without
endeavouring to  penetrate  further ;  beyond, an immense
abyss commences ; we should take care lest we fall into it.
   The General Anatomy contains  also the first germs of
a science to which Bichat would no doubt have  devoted
his whole  life,  I  refer to morbid  anatomy.   It was a
natural  consequence  of  his  first  labours;  after having
studied the structure and functions of the organs, and per-
formed  upon  living  animals experiments for  the  exact
observation of their phenomena, either in a state of health
or in  that  of disease, he was naturally led to seek  for a
knowledge of the changes in their texture which this last
state brings.
   Appointed, at the age of twenty-nine, physician to the
Hotel Dieu, he devoted himself to this kind of research
with all the activity that was natural  to him ; in  one single
winter he opened more than six hundred bodies, and soon
after he stated in a course of lectures his observations upon
the morbid state of the organs.  It was in this course that
he demonstrated that  each texture has a peculiar mode of
disease as it has a peculiar character of vitality ; that even 
HISTORICAL  NOTICE.
xm
in the  intestines, the morbid  state of a membrane can
connect itself with the sound state of the neighbouring
membranes, and that it is very important to know how
to distinguish, by a correct analysis, the peculiar suffering
of these different textures.   Bichat began to unite into a
body of doctrine the  fragments of morbid anatomy scat-
tered throughout his works ; he would have raised to the
science a monument worthy of it and of the great epoch
which owed to his labours a part of its distinction.  But
he died during the printing of his Treatise on Descrip-
tive Anatomy, the two first volumes  of which he pub-
lished himself, (in 1801 and 1802) and left the  third im-
perfect.
  One day, after having visited some specimens of morbid
anatomy subjected to maceration and having been exposed
without any precaution to their noxious  exhalations, he
fell in descending  a staircase of the Hotel-Dieu, and the
slight shock occasioned by this fall deprived him of his
senses.  A violent affection  of the head, very severe gas-
tric symptoms, a continual tendency to stupor and ataxic
phenomena succeeded with rapidity, and Bichat sunk on
the fourteenth day of his disease, 22d of July, 1802.
  Thus were turned to bitter regrets the hopes that he was
just realizing; thus was arrested in  his  rapid flight this
genius who seemed to hover over the whole  edifice  of
medical science.  Bichat, embracing in a single vie.w all
the knowledge connected with medicine, saw on the one
hand anatomy brought to the greatest degree of exactness,
physiology established for the  first time  upon facts, and
the description of diseases reduced to  simple  and clear 
XIV              HISTORICAL NOTICE.
language ; and on  the other,  morbid anatomy still separ-
ated from physiology, and therapeutics still abandoned to
empiricism.   He had conceived the project of connecting
by a regular chain  all the parts of the art  of healing, of
raising  a complete  system of medicine  founded  upon
anatomy, upon the study of the functions in the state of
health and in that  of disease,  upon the distinction  of  the
textures, the sympathy which connects them together, the
observation of the local and  the  general effects of medi-
cines, and the results of the examination of dead bodies.
He would no doubt have  executed this  plan, vast and
methodical as it is,  which, notwithstanding the preten-
sions of some physicians of our time, is yet but a project.
  Such is in fact the happy influence which the great men
who appear from time to time have upon  their age, that
from their labours  as from an inexhaustible source, new
sciences seem to flow.  Those who have nothing  to  say
continually repeat what has been said ; but before the man
of genius the field of discovery seems to enlarge from day
to day.   How many researches has he to make in morbid
anatomy,  a  physical science, which only considers  the
symptoms of diseases as the signs which should be refer-
red to the alteration of the textures, who  seeks in these
textures  the  various lesions  produced by  the  different
degrees of diseases, and who  only endeavours to go from
the alterations to the symptoms !  How little advanced is
morbid physiology, the knowledge of the functions of the
organs by the different modifications which the alterations
produce in these functions, which will alone resolve an
infinity  of enigmatical  problems of  our organization, and 
                 HISTORICAL  NOTICE.               XV
especially make known by pathological analysis the  dif-
ferent properties of the nervous system !   How much has
anatomical chemistry been neglected even  to this day,
the research into the composition of the textures, which
would  alone be able to establish the identity or the differ-
ence of the systems and the apparatus of the human body !
Pathological chemistry, the investigation of the chemical
changes produced by the alterations in the organs, is it
not an  entirely new science, upon which we  have hardly
thought,  and  which will perhaps give the explanation of
many phenomena, whose character and cause we are un-
able to determine by other means ?
  How many  researches has  Bichat opened for us the
way !  What  an immense inheritance has he left  us to
improve !  The mind can hardly conceive that the life of
one man  was sufficient for  so  many labours, for so  many
discoveries, either made or pointed out; Bichat died
before he completed his thirty-second year !
                                  SCIPIO PINEL. 
 
GENERAL. ANATAOMY.
           ADDITIONS

                TO THE

GENERAL  OBSERVATIONS.
               Anatomical Elements.

  Page 49, volume  1, Bichat's  General Anatomy.—
■" If you  would have  only general notions of anatomy,
you can study each  organ as a whole; but it is essential
to separate the textures, if you have a desire to analyze
with accuracy its intimate structure."

  Some have attempted to extend too far this analysis of
the  textures ; and, as  in chemistry, we recognise in the
organic substances the immediate principles which them-
selves result from the union of the  simple  elementary
bodies, such as oxygen, hydrogen, carbon and azote, they
have sought to discover what  are, in  the organization of
animals,  these primitive elements,  the  assemblage  of
which, variously modified, gives rise to  the secondary
textures,  to the organic systems of Bichat.
             3 
IS
ADDITIONS to the
      The ancients had already admitted an elementary fibre,
    {fibra simplicissima) composed of earthy particles united
    by a species of gluten, and being able to assume two forms,
    the one linear and  the other lamellated.  This fibre was
    the base of the cellular texture, which  they regarded as
    the substratum of all the solids of the human body.  But
    this elementary fibre has never been seen, and moreover,
    there are textures which we cannot  reduce by decompo-
    sition to the simple cellular substratum.
      An opinion more conformable to nature is that which
    recognizes  in the organization  three distinct  elements,
    the cellular, nervous and muscular fibre.   Very  striking
    differences characterize these three primitive textures, and
    do not permit them to be confounded.   1st. In relation
/   to the form ;  the cellular fibre is composed of fine laminae
    and delicate filaments, white and extensible ; the nervous,
    of a soft substance  nearly fluid,  contained in a cellular
    envelope ; the muscular, of round filaments, soft, pulpy,
    greyish or red.  2d. In  relation to the chemical nature ;
    one is resolved into almost pure gelatine when it is treated
    with boiling water  ; the other  is essentially formed  by
    albumen united to a fat substance, and the third by fibrin.
    3d. In relation to the vital properties ;  those of  the  cel-
    lular fibre are obscure and are  confined to the latent sen-
    sibility and  the invisible contraction known  under the
    name  of  insensible organic  contractility, whilst  the
    nervous has, besides the faculty of transmitting the im-
    pressions to the mind, sensibility properly  so called; the
 )  muscular on the contrary, is distinguished by the irrita-
    bility which it possesses.
       All the organized textures  have for their base one  of
    these three  primitive fibres, or result from the union  of
    many of them ; thus the cellular element is  found in most
    of  the  organic systems; it constitutes  almost alone the 
general observations.
19
cellular texture, the serous membranes, the dermis of the
skin and of the mucous membranes, the parietes of the
sanguiferous  and lymphatic vessels, and the fibrous or-
gans ;  thus the  muscular system is formed by the assem-
blage of the muscular and cellular  elements, &c.
   This division of  the primitive textures, pointed  out
by Haller and Blumenbach, has been followed by most
modern anatomists.   Some have  modified it by adding
to them a fourth element, the fibrous texture.   It is to
this new fibre that M. Chaussier  has given the  name of
albugineous fibre.   The characters  which he gives  to it
are a white colour, shining like satin, and a considerable
density; boiling water converts it in great part  to gela-
tine ; it is but slightly extensible and very resisting ; its
vital properties  are  hardly perceptible;  it  is this which
forms the fibrous or  albugineous membranes, the tendons,
aponeuroses and ligaments.   These characters resemble
very much those of the cellular fibre,  from which the albu-
ginea seems to differ only in the greater approximation of
the particles, which is  the  reason  of the greater  tenacity
it possesses.   We can  even refer to  a modification of the
cellular fibre the elastic, yellowish texture,  which consti-
tutes  the  middle texture of the arteries, the yellow liga-
ments  of the vertebrae, the posterior cervical ligament of
animals, &c. and which is distinguished by its colour  and
its elasticity from the common or albugineous fibrous tex-
ture  of M. Chaussier.   Nothing proves  more  the great
affinity which naturally approximates the cellular fibre  and
these two species of fibrous textures, than the facility with
which they are transformed  into cellular texture, when
they disappear preternaturally.
  If we consider the organized elements  under  another
point of view, we see that it  is possible  to  bring by  the
analytical  method the  different textures  of the  animal 
20
ADDITIONS TO THE
economy to a certain number of  primitive forms, which
are inseparable elements of all organization.  This obser-
vation has occasioned many  classifications of forms  or
elementary textures.  The first and most  simple is that
which admits but  two of "them;  1st, the fibrous form;
2d,  the lamellated form, a division already established
by the ancients.   A greater extent in length characterizes
the fibre ;  the lamina has  dimensions nearly equal  in
length and breadth, but little thickness.  The  fibres and
the laminae can by their interlacing  leave between  them
spaces variously formed, called cells.  The fibrous struc-
ture predominates ;  it is evident  in  the nerves, the mus-
cles, the bones,  and  the  fibrous  textures; some organs
exhibit at  the same  time  a  fibrous and lamellated tex-
ture.
   Others recognise a greater  number of elementary forms
and add to  the two preceding ones the  globular and the
granulated  form;  the  first belongs  especially to the
fluids ;  the  second is observed in the  glandular texture.
They admit besides as secondary  forms, 1st, the cellular;
2d, the vascular;  3d, the solid, as that of  the cartilages,
the bones, &c.
   Other divisions also exist which  appear  to be founded
at the same time upon the  forms  and upon the nature  of
the textures.  It is  thus that Walter  establishes,  1st, a
cellular or membranous texture ; 2d, a vascular or fibrous
one; 3d, a nervous one.   So we  find in the classification
of  Dumas,  1st,  the cellular or spongy texture; 2d, the
muscular or fibrous texture; 3d, the mixed or parenchy-
matous texture;  4th, the  lamellated or osseous  texture.
These divisions are by no means preferable ;  they are in-
sufficient  if  they represent the  secondary textures  or
organic systems, and too multiplied  if they only express
the primitive elementary forms. 
general observations.
21
  Notwithstanding the delicacy of microscopic researches
and the deceptions so difficult to be avoided in this  kind
of experiments, the labours of Hewson, Prochaska, Wen-
zel and other observers, have served for the  basis of a
theory of the organized elements which differs considera-
bly from the other opinions upon this subject, and which
has been particularly developed latterly by J. F. Meckel.
  According to this anatomist, the solids and the fluids of
the human body can be  reduced, in the last analysis, to
two elementary substances, one formed by  globules,  the
other by a coagulable matter, which, either alone or united
to the first, constitutes the living solids, if it be in a liquid
state, and gives origin to the solid textures,  if it be in  a
concrete state.
  The globules exhibit, in their appearance  and even in
their nature, differences which are  especially relative to
the places in which they  are  examined.  In the blood,
they appear flat and composed of a central part which is
solid, and of an external part  which is hollow and vesi-
cular.  Those  of  the kidneys are  smaller than those of
the spleen; the globules of the liver are still more deli-
cate.  The globules contained in  the substance  of  the
nerves exhibit a less size than those of the  blood; it  is
the same in the lymph, the milk and the chyle.   Certain
fluids, as the urine, do not contain globules.   Many solids
are entirely destitute of them ; such are  the cellular  tex-
ture, the fibrous parts, the cartilages and the bones.  They
abound on  the contrary in the blood, the nerves  and  the
muscles.   They form the essential  part  of the  textures,
the  colour  and nature of which they determine.
   These globules  appear to undergo modifications accord-
ing  to age ; but  direct  experiments are wanting on  this
point.   Hewson says he has  found in birds and  reptiles,
the globules of the blood  of a different form and size  in 
    22               ADDITIONS TO THE

    the  embryo and the adult animal.   In  the  first periods
    after conception, the mucous and homogeneous mass which
j    constitutes  the  embryo  does not  contain  globules; it is
    not till a more advanced period that it is composed of two
1    substances,  one  fluid and  the  other  solid, every where
    immersed in the first.  The globules are then very appa-
    rent, more distinct than they will be afterwards ; they are
    seen in all parts of the embryo.
      These two elements,  the globules and the coagulable
    fluid, may  assume the form of fibres or  laminae.  The
    lamellated form  belongs  almost  exclusively to the fluid
    matter.  The fibres may  be formed by this substance only,
    as we see in the bones,  the tendons,  &c.  ; they are the
    effect most  often of the union of the globules  and the con-
    crete fluid, of which the  nervous and muscular systems
    exhibit examples.
      These considerations of Meckel upon the organization
    of animals  have some relation with  the division of the
    organized elements established by PfafF,  which admits as
    primitive elements fibres and cells, themselves formed of
    a series of  particles or globules.   They differ from it in
    this that we find in it, besides the solid globules, the idea
    of a concrete fluid substance, analogous to  that which the
    ancients designated by the name of gluten.  It is accord-
    ing  to Meckel  the cellular texture which  represents this
    substance ;  it regards in fact this  texture as a sort of con-
    crete fluid,  as we shall see in the article on the cellular
    system.

             Classification of Morbid Anatomy.

      Page 59.—" This  course  (of classing  the alterations
    according to the systems to which they belong) is incon-
    testably the most natural, though, as in all divisions in 
               GENERAL OBSERVATIONS.            03

which we wish to subject nature to  our views, there are
many cases which it almost excludes."

  The recent progress of morbid anatomy has occasioned
new classifications which, without being entirely exempt
from  the  inconvenience of constrained approximations,
nevertheless contain useful divisions founded upon natural
relations established between the various organic altera-
tions.  Bayle, Laennec, Cruveilhier, J. F.  Meckel,  &c.
have been particularly  engaged in this subject.
  1st. Having seen that the alterations  of  texture have
nearly the same characters, whatever  may be the tex-
ture they affect, they have found the greatest advantage
in uniting them into  one and  the   same  class,  so that
they avoid the numberless repetitions which an opposite
method produces ; they exhibit at  the same time and
under the same point of view,  analogous objects,  and no-
thing is more proper, as we know, to hasten the progress
of any science.
  2d. The same method has been applied, though with
less success, to  the derangements that affect only the ex-
ternal forms.  It is scarcely any where but in the  original
defects  of conformation that a  methodical  order can  be
followed or that it is attended with any real  utility.   The
preternatural derangements of form have too little resem-
blance,  to make it  advantageous to approximate  them.
Thus it has been  proposed to preserve  here the anatomi-
cal  order adopted by Bonet,  Morgagni and in part  by
Bichat, till  the  science  shall be sufficiently advanced to
substitute another for it.
  They  have followed the same principles, as much as
possible  in   the  subdivisions.    The most natural and
numerous is  that of the transformations or organic pro-
ductions, which the class of the alterations of texture em- 
24
ADDITIONS TO THE
braces.   They are characterized  by  the  preternatural
development of a  new  texture in the part which is the
seat of them.  They are divided, according as this texture
has some analogy in the economy or is wholly foreign to
it, into organic transformations properly so called,  and
into degenerations or preternatural textures which only
exist in a state of disease.
  J.  F. Meckel is hitherto the only  one who has made
an application of these data  to  a complete  system of
morbid anatomy.   The  following is the  order  which
he has pursued  in a  very extensive  treatise  that he has
published in Germany on  this subject:
  He admits  the  two great divisions of  which  we have
spoken, viz. the alterations of form and those of texture.
Among the first are found arranged,  1st,  the original de-
fects  of conformation,  subdivided  according  as they af-
fect  the number  or nature of the parts,  into  defects of
quantity and defects of quality ; 2d, acquired  derange-
ments of size, situation,  configuration,  &c. which com-
prehends luxations, hernias, solutions of  continuity, con-
tractions, dilatations, atrophies, &c.
   The alterations  of texture are confined  to two principal
heads.  Some change only the physical properties  of the
affected  texture,  such  as the colour and density.   The
others completely change its organization.   These being
often the product of inflammation, this  affection is naturally
placed here.  The manner of the separation of the injured
organs is described at the same time.  Finally come the
transformations  and  degenerations properly  so  called.
The  author still ranks among the^ preternatural produc-
tions worms and concretions. 
GENERAL OBSERVATIONS.
25
   We shall adopt the following order in the exposition of
the morbid alterations of each system.
1st. Alterations in the exter-^
        nal forms
                          Situation.
                          Size          \ Hypertrophy.
                                       ( Atrophy.
                          Density.
                         ^Configuration.
                         f Inflammation.

                         I Mechanical Lesion \ Wounds-
2d. Alterations  in  the  or--{                  ( Foreign Bodies.
      ganization by        | Transformation.
                         ^Degeneration.
n i  tl.   .•   •  .■  j   ,       .( Defects of conformation.
3d. Alterations in the development < D  .   .   , ,^   ,      .
                         v     ( Preternatural Development.
4 
 
ADDITIONS
            TO THE

CELLULAR SYSTEM.
                  Adipose Texture.

  Page 128.—"We shall see also, that the fat is sepa-
rated by an exhalation analogous to that  of  all the other
exhaled fluids, that is to say, by  vessels of a particular
order, which are intermediate between the extremities of
the arteries and the cellular texture.  We  can  apply to
the exhalants  of fat, what will be  said upon the exhalant
system in general."

  The fat  does not appear to be simply deposited in the
small spaces of the cellular texture ; it has a texture which
is peculiar  to it and which contains the oily fluid of which
it is formed.   The existence of the adipose texture, which
was imperfectly known  to Malpighi, distinctly pointed
out by A. de Bergen and Morgagni, has  been particularly
demonstrated  by W. Hunter.  It has been  described in
turns under the names of cellular texture, by calling our
cellular texture filamentous, of fatty texture  or pan-
nicle,  of  adipose  membrane or  network, of  adipose
tunics or vesicles, &c. 
28
ADDITIONS TO THE
   The general arrangement of the adipose texture already
 exhibits many peculiarities which cannot arise  from the
 fat; this  fluid cannot of itself have a determinate form,
 and nothing is more variable than  the  external confor-
 mation  of the fatty texture.   In one place it is a  mem-
 branous layer more or less thick, analogous to that which
 exists  under the skin, in which  it constitutes  the  fatty
 pannicle.   In another it is in irregular masses, such as
 are found around the kidneys, in the orbits and  the thick
 part of the cheeks.   In other places the adipose texture
 exhibits the appearance of pyriform elongations, pedicu-
 lated, such as are seen in the appendices  of the omentum,
 around  the  arteries  which go  to the peritoneum, in the
 openings  of the  umbilicus and  the  infra-pubien  rings,
 &c.; in the omentum it forms flattened ribbons  or  kinds
 of network which follow the course of the blood-vessels.
 Accumulated in some parts, it appears under the form of
 tumours more or less large  and prominent, examples of
 which are seen in the eminences upon the nates of Hotten-
 tot women,  in those on the backs of dromedaries, camels,
 the bos  urus, and the tail of the Barbary sheep.
   The adipose texture, considered in its  external organi-
 zation, is not less distinct from the fat which it contains.
Whatever may be the different forms it assumes, its struc-
ture is every where the same.   It is divided into rounded
 bunches, separated from  each other by grooves  more  or
less  deep, of a form irregularly  oval, and  of a  diameter
varying from a line  to half an inch ; their size differs also
according to the degree  of corpulency and according  to
the part examined.   Each of them is composed of smaller
particles, which are easily separated by dissection.  These
are spheroidal, miliary, compressed, similar in form to the
seeds of the grape  or still more to the vesicular granula-
tions which  constitute the inside of oranges, and  other 
CELLULAR SYSTEM.               29
fruits of the family of hesperides ; we discover, by the
aid of the microscope that they are  themselves a collec-
tion  of united vesicles, exhibiting precisely the same ap-
pearance, except  as to  size,  since according to Monro,
their diameter is from the  eight hundredth to  the six
hundredth of an inch.   According to Wolff these vesicles
may have a different  size in different species of animals.
They do  not  appear to communicate with each other;
their parietes are delicate and  transparent, which has
made Monro  and Clopton-Havers who  have observed
them in the marrow of the bones, compare them  to col-
lections of small pearls.  They contain the fatty fluid, the
yellowish colour of wdiich is visible.
   The adipose texture is provided with a vascular  appa-
ratus, which has been  very well described and drawn by
Mascagni.   Arterial and venous  branches are lodged  in
the grooves which separate the fatty particles; their divi-
sions represent, by their anastomoses, capillary networks
which run  along  the  interstices of the small masses  or
particles of which they are composed ; each of these par-
ticles receives a little artery and a little vein which form
for it a sort of vascular pedicle; the microscopic vesicles
themselves  are penetrated  by the most delicate ramifica-
tions, which follow at first their interstices, form for them
also  a kind of  pedicle and  finally  terminate  in  their
parietes.   This  collection  of vessels  and agglomerated
grains  has  some  resemblance to a bunch of grapes sus-
pended by its peduncle, and in which each of the grains
that compose  it, has  besides  its  own  pedicle.   This
arrangement is easily  seen upon a  portion of fat  taken
from an injected body, or still better from  a part naturally
infiltrated with blood.
   A very delicate cellular texture seems to exist between
the vesicles and around them  ; this texture becomes more 
30
ADDITIONS TO THE
apparent in  the  interstices of the particles visible to the
naked eye, which it connects together ;  the little bunches
that arise from them are united by a firmer texture almost
fibrous in some parts, evidently ligamentous in the palms
of the hands, on the soles of the feet, &c.
   The fatty texture no doubt contains  absorbent vessels,
but we are ignorant of their arrangement.   It is the same
with regard  to the nerves.  Its  intimate nature appears
to resemble  very much that of the cellular texture.  It is
in fact a soft  substance, whitish, extensible, contracting
when distension is removed, appearing  under the form of
fine and  semi-transparent laminae and having the greatest
analogy with the lamellated  or cellular fibre.  If the  fat,
which it contains, disappears preternaturally, the vesicles
flatten and are confounded with  the surrounding cellular
texture,  without  leaving  any trace of  their existence.
Hunter says,  nevertheless, that in these cases the cellular
texture  differs in some of its properties from that which
never contained adipose  vesicles, and he attributes these
differences to the presence of the empty vesicles which
the first contains.
   It would  be  wrong to  conclude from the resemblance
that is found between the fatty and cellular textures that
they are precisely the same.  It is easy to  point out  the
characters  which distinguish them.  1st. The adipose
vesicles  are shut  on  all  sides, and  their substance is not
permeable to the fluids which tend  to  penetrate it, very
different in  this from the areolar substance of the lamel-
lated  texture.   This  is proved  by many facts.   Take a
piece of adipose texture,  raise its temperature gradually
by means of warm water,  until it is sufficient to melt the
fat without  altering the structure of  the vesicles, the oily
matter  will remain  contained in  them without flowing
out.  Expose a bunch of fat to the heat of  the sun suffi- 
CELLULAR SYSTEM.
31
cient to raise the centigrade thermometer to + 40 degrees,
you  are very  certain that at such a temperature the fat
must  be perfectly fluid ;  yet not an atom of it will flow
out; cut some  of the  vesicles, and  the  oily  fluid will
immediately appear.  We obtain also the'same result by
compressing between the fingers  a fatty mass ;  the fat
does not escape unless the vesicles are  ruptured.   In the
most  extensive  emphysemas, in the greatest serous infil-
trations, the effused  fluids never penetrate the vesicles;
the fat  remains distinct  and is not  mixed with these
fluids.   If it were otherwise, should  we not  see during
life, the fat, fluid at the ordinary temperature of the body,
constantly descending to  the lowest places, as takes place
with  the serum of dropsical  patients, yielding to  external
pressure in  parts which, such  as  the  feet and the nates,
are continually  subjected to  it, as is observed  also in
oedema ?   The  adipose  vesicles do not  form, like the
cellular texture, one continued  whole; they are  merely
contiguous to each other.  This is easily demonstrated by
inspection.  It is also seen in anasarca; the liquid, which
is poured in the cellular texture  that is interposed be-
tween the adipose particles, separates them, and they con-
tinue  insulated  in the serum that surrounds them.  3d.
There  is  another character.  Wherever  cellular texture
is found, there are parts  always destitute  of the fatty tex-
ture, even in the fattest subjects.  Does not this fact seem
to indicate, that there must be  a peculiar organization  in
the cellular texture, that  fat may be developed in it?
4th.  Finally their uses  are  very different ; those of the
 adipose texture only relate to  the fat that is  constantly
exhaled in  the interior of its  vesicles,  and  constantly
taken up  by the absorbent vessels; the  cellular texture
has much more important uses, since  it forms  a  common
link  which  unites all  the parts at the same time that it 
32
ADDITIONS TO THE
insulates them, and serves to facilitate their motions and
to maintain the harmony of their functions.

             Chemical Nature of the Fat.

   Page 128.—" I  will not treat of the  chemical nature
of fat.   This would lead  me  into  details  foreign to this
work.   Besides,  I  could add nothing to what modern
chemists have said  upon this subject."

   The recent labours of M. Chevreul upon the fixed oils
and the different species of fat, have given results too satis-
factory not to be mentioned here.   The fat, far from be-
ing an immediate principle  of animals, as has for a long
time been thought, is composed of two peculiar principles,
non-acid, designated from their consistence, by the names
of stearine and ilaine.
   Stearine exhibits a solid  mass,  without colour, almost
inodorous, insipid, soluble in  alkohol and  preserving  the
solid  state at the temperature of  38 degrees of the  cen-
tigrade thermometer.  Elaine on  the contrary, is fluid at
a  temperature of 17  or 18 degrees ;  it is  without  colour
or yellowish, lighter than water and much more soluble in
alkohol than stearine.  It is  by taking advantage of this
last property, that we can separate these two  principles.
For this purpose we  treat a certain quantity of fat with
boiling alkohol ; as the liquor becomes cold  the stearine
is precipitated, taking with  it a little elaine ;  the  greater
part of the elaine remains in solution with a little sttjarine.
The action of cold  upon fat, and the continued contact of
this substance with paper that has  not been sized, can also
serve to demonstrate  the existence of its immediate mate-
rials.   In  the first case,  the  stearine becomes solid, whilst
the elaine preserves its fluidity;  in the  second,  the 
CELLULAR SYSTEM.
33
elaine is absorbed by the paper and the stearine remains
on the surface.
  The proportion of the principles of the fat is not the
same in all animals nor  in all parts  of the same animal,
hence all the varieties of consistence  which that of man
exhibits.   However, as stearine  is not more solid, even
when pure, at a degree of heat  equal to the temperature
of the body, the fat ought  at least  to be semi-fluid during
life, and this is  in fact what is observed in surgical  opera-
tions, during which there often flows with  the blood some
oily drops coming from the cutaneous adipose vesicles.
  Besides the  peculiar  acid, (the  sebacic  acid) which  is
produced during the distillation of fat, there are two others
that are obtained  by treating it  properly  with an   alkali
or some metallic oxyd ;  one is the  margaric acid,  so
called  from  its pearl  colour, the other  the  oleic acid.
Soaps, which result from  the action of alkalies upon oils
are nothing but salts formed  by these two acids and the
base that is  employed.   M.  Chevreul thinks that some-
thing analogous takes place in the spontaneous decomposi-
tion  of muscular flesh, when it happens without the con-
tact of the air; he considers the fat of dead bodies which
is produced in this way as a kind of  soap, which is the
result of the action of the ammonia coming from the de-
composition upon the fat contained in the  muscle.

       Intimate nature of the Cellular Texture.

   Page 131.—" All these vague ideas of concrete juices,
of inorganic glue, of hardened juice, that have been applied
to the cellular texture, have  no solid  foundation, and rest
neither upon experiment nor observation, and ought to be
banished from  a science in  which imagination is nothing
and facts every thing."
              5 
34
ADDITIONS TO THE
  The ancients do not  appear to have been  acquainted
with the cellular texture, at least they do not mention it
in their writings.   It is without cause that some have
pretended, that they have found some notions of it in  a
passage of Hippocrates, in  which the question is respect-
ing the general permeability of  the textures.  Adrien
Spigel is one of the first who have spoken of it.  Vesalius
and others made it known successively in different parts
of the  body.   It is only since Haller and  Bergen  that it
has been  considered as  generally distributed to all the
parts.   Bordeu appears to be the first who compared the
cellular texture to  a sort of slaver or glue.   Quesnay said
that it  rather resembled a fluid matter than  an  organized
solid.  Wolff went further; rejecting all idea of cells, he
regarded the  cellular texture as a homogeneous substance,
glutinous and without evident organization.  Blumenbach,
Era. Platner and J. F. Meckel, have adopted this opinion.
This last has made the cellular texture his  concrete fluid
element.  The following are  the  observations and facts
upon which these anatomists rely.
  1st.  Inspection,  say they, does not discover in the cel-
lular system the fibres or layers of which it is supposed to
be formed.   Examine   it under the  skin,  between  the
muscles, around the arteries, on the exterior of the  mem-
branes, everywhere is  found a substance semi-fluid,  trans-
parent, tenacious  and without any appearance of fibrous
or lamellated structure.   If fibres or laminae be developed,
it is owing solely  to the means  of investigation that are
employed.  Thus  when we separate from each other two
contiguous organs,  which are united by cellular texture,
two muscles, two  fasciculi of the  same  muscle or two
muscular fibres ; when we raise this texture from the sur-
face of the organs it covers, it yields to the distension, is
elongated and presents the appearance of delicate laminae, 
CELLULAR SYSTEM.
35
which are changed to round filaments if the distension be
carried further, precisely as if it were a  piece of glue or
paste, according to the expression  of Bordeu.   The dis-
tension having ceased, the parts approximate, and the in-
terposed  cellular  layer reappears homogeneous and  per-
fectly continuous.   So when we examine the cellular tex-
ture of the scrotum by stretching it to a kind of membrane,
it is evident that the laminae and the interlaced filaments
that are seen are  the  product of distension, and this ap-
parent organization is not observed until after having de-
veloped it artificially.
  2d. These  pretended cells do not exist either in the
mucous texture, which does not exhibit openings on its
surface, as it would  if there were these little cavities.
When cavities are found there, it is because foreign bodies
raise it up and give it a vesicular appearance.   When, for
example, the cellular texture is drawn in  different direc-
tions, it often happens that it is penetrated with air in itg
interior.  This air then assumes the form of bladders, as
it does in soap suds.  But if we press upon these bladders,
they disappear ;  and, if we  afterwards reproduce them,
they may be very different from the first.   We give them
very various forms, increase or  diminish  their number,
precisely as in soap suds.   Inflation produces also in the
mucous texture a cellular appearance, which is explained
in the same way by its state of softness  and semi-fluidity.
The injected air penetrates it easily, and the distension,
which it occasions, produces that appearance of fibres and
interlaced laminae, which has been said  to be peculiar to
this texture, whilst it is a form which it possesses but for
a moment.   It is the  same with  regard to the cells ob-
served  after  congelation ;  they are interstices preternat-
urally produced by the presence of a fluid diffused in the
cellular texture. 
36
ADDITIONS TO THE
  3d. Any part of the cellular system exhibits by turns,
fibres, laminae or cells, according to the process employed
to develop in it either one or the other structure.  Dis-
tension produces laminae  or fibres, according to the extent
to which it is carried ; inflation produces cells, &c.
  4th. The cellular  texture is permeable ;  most fluids,
such as air, water, pus and urine traverse it easily  and
run over a great extent in its interior;  solid  bodies even
have penetrated it, and have gone longer or  shorter  dis-
tances.   How can we admit that bodies thus immersed in
the mucous texture follow precisely the direction of the
cells and of their orifices ?  Is  it not rather the medium,
and, as it were, viscid consistence of  this texture which
permits it to yield to the effort of the substances which
tend to penetrate it, and  accommodate itself  at the same
time to the various forms which they imprint upon it ?
  5th. Finally, they add, that in the foetus of man and in
the lowest classes  of animals it is  impossible, under  any
circumstance,  to discover any organization in the cellular
texture ; a mucous and homogeneous mass only is found.
  It is for anatomical inspection  to pronounce upon the
validity of these objections, which  cannot be overthrown
by  the single consideration of the phenomena of vitality
which the cellular texture exhibits in  diseases.  Would it
be the first example of a  texture endowed with life, whose
homogeneous  structure  did not  allow distinct laminae or
fibres to  be seen ?  Is it not so with the cerebral substance,
the cartilaginous texture and the  serous membranes ?  We
do  not seek to know if the texture peculiar to the cellular
system be the seat of an evident vital action ; this point
would not be contested, but only if we should admit that
it has a fibrous or  lamellated organization, or whether this
organization is developed, except under certain influences
 of which it is the immediate result.   What is certain is, 
CELLULAR SYSTEM.
37
that  it  appears  under many circumstances as if it were
really spongy or  cellular, and  there  can  be  no  incon-
venience in regarding it as such.
      MORBID ANATOMY OF THE CELLULAR SYSTEM.

         I.   Alterations in the external forms.

   The size of the cellular texture can be  increased in
 consequence of a  more copious exhalation of the fluids it
 contains.   This is what happens in anasarca and in obesity
 or corpulency.  The serum accumulated in anasarca resem-
 bles that  of dropsies.  It runs moreover freely through
 the  cellular texture, and collects in general in the  most
 depending parts.  The looseness of this  texture in some
 regions disposes it also to infiltration.  In old oedemas, the
 cellular texture sometimes acquires a very  great  thick-
 ness ;  it seems as if there were made an exudation of a
 fluid capable of concretion which increases its density by
 adding to the laminae which compose it.
  Obesity or the  accumulation of fat is general or local;
 the first has been examined under  the article upon the
 cellular fat.
  Fatty tumours, which constitute the second, are of very
 various forms; their size is sometimes very considerable;
 frequently they are provided with a pedicle through which
 the vessels  enter.   A cellular coat  invests them on the
 exterior;  their structure i6 that of the adipose texture.
 The vesicles appear to  be more numerous than  in a state
of health, for Monro has  observed that their diameter is 
38                ADDITIONS TO THE

the same.  These tumours are especially developed  in
parts  which contain much fat; hence  the  frequency of
wens  or sub-cutaneous fatty tumours.
  Besides the fluids naturally contained in  the  cellular
texture, air can also accumulate in it, which constitutes
emphysema.   This last is more or less extended.   It is
sometimes  developed after  death,  in apoplexy,  urinous
effusions, &c.
  An  increase of  size  and density at the  same  time
appears to constitute the disease described under the name
of hardening of the cellular texture.  There is only found
in it  in fact a greater thickness and consistence of this
texture, which scarcely  }*ields  to  the pressure of the
finger;  there  is  usually  joined  with it a  more or less
considerable serous infiltration.  This affection is, as we
know, almost  exclusively confined  to new  born  infants.
It is below the skin that it  most commonly appears; it
has also been seen in the inter-muscular cellular texture.
  The elephantiasis or disease of Barbadoes is owing to
an alteration of the same kind.

         II. Alterations in the organization.

  Inflammation of the cellular texture is very frequent;
there  are many varieties of it, particularly  according  to
the part it attacks.
  In acute inflammation, in phlegmon properly so called,
the cellular texture is of a more or less bright red,  as if
infiltrated with blood ; the serum disappears,  the  small
spaces being obstructed are much less permeable  than  in
the natural state; they are afterwards filled with a concrete
albuminous matter, which resembles a kind of jelly.   The
ulterior phenomena differ according to the mode of termi-
nation.  In the most common  cases, suppuration takes 
CELLULAR SYSTEV1.
39
place, the pus hollows out a cavity which is continually
enlarging, and an  abscess is  formed ;  or  there is an ab-
sorption of the effused albuminous matter, and consequent
resolution.   At  other times this matter seems  to  become
organized at the same time that its consistence increases ;
it is insensibly confounded with the organ which furnishes
it;  this is what is  observed in the termination by indura-
tion.   In gangrene, the mortified cellular texture produces
soft eschars, of a whitish or grayish colour; it is  reduced
to a sort  of putridity.
  Chronic inflammation especially produces induration, as
we see in old ulcers.  We frequently find  as its conse-
quence that sort of brittleness of which Bichat speaks
(page 142).  In some cases the  inflammation is accompa-
nied with ulceration and  destruction of the cellular tex-
ture.
  The cellular texture, when simply divided by a mechan-
ical lesion, unites quickly, if the divided edges be in con-
tact ; this is what takes place in the closing of abscesses,
in the union of wounds by the first intention, &c.  The
adhesion is established by  means of a coagulable fluid
which is effused, becomes concrete and organized, so as  to
form a new texture for some time more dense than the
surrounding cellular texture, with which it finally becomes
confounded.
   The cellular  texture, laid bare by a solution of con-
tinuity with a loss of substance, exhibits  all the phenom-
ena described in the formation of fleshy granulations and
of  cicatrization.   Vanhoorn has seen in amputations the
fatty cellular texture disappear at  first from  the surface
of the wound, to be afterwards replaced by a new texture,
more dense and resisting than the first.
   Foreign bodies introduced into the cellular texture pro-
duce there a more or less severe inflammation; the suppu- 
40
ADDITIONS TO THE
ration which results from it brings them gradually to the
exterior, so that if they be deeply situated, they thus go a
considerable distance.  We see this texture then approxi-
mating, constantly uniting behind the foreign body, whilst
it  suppurates and opens before it.   This  peculiar course
of the inflammation has given it the name of  the expul-
sory inflammation.
   In some cases however,  foreign bodies remain in the
cellular  texture  without producing  any inconvenience
there ; there is formed around them a kind of membrane,
a cyst,  which keeps  the  neighbouring parts from  their
contact; this is what takes place in  some  sanguineous
effusions, when the  presence  of the  coagulum  does not
occasion the formation of an  abscess.  The  sac, which
contains the blood in false  aneurisms, is  produced by an
analogous mechanism.
   Besides inanimate bodies, solid, fluid or gaseous, which
preternaturally enter  the cellular texture, we find there
real animate bodies, worms.  The  cysticercus cellulosoe,
the filaria medinensis or hair snake properly called, and
the larvae of the oestrus have been met with by different
observers,  not  only  below the skin, but in the inter-
stices of the muscles, in the substance of the pia mater,
and even upon the bones.
   Various natural textures of the economy are preter-
naturally developed in the cellular system.
   Osseous and cartilaginous transformations  and produc-
tions are not  rare in it; they are  observed  particularly
in the cellular texture which exists in the neighbourhood
of the serous and synovial membranes, sometimes even in
that which penetrates the substance  of  the  organs,  and
less  frequently  in  the  sub-cutaneous  cellular  texture.
The fibrous texture frequently appears also in the lamel-
lated texture ; we find  examples of it in the parietes of 
CELLULAR SYSTEM.
41
certain cysts,  in the production of fibrous tumours, &c.
It is  to  the transformation  of  this texture into serous
membrane that must be referred the production of  most
cysts, which are developed at its expense.  Motion also
produces in  some places preternatural serous membranes.
( Vide Serous System.)  Abscesses and old  fistulas are
lined  by  a membrane which has  some analogy with  those
of the mucous system.
   All these  various forms, which the cellular texture can
assume, ought not to surprise us, when we  recollect that
the fibre  which constitutes it makes at the same time the
base of most of the organic systems.
   Degenerations, properly so called, are very common in
the cellular texture; the more  abundantly an  organ is
provided with it, the more is it exposed to this kind of
affections.   But they do not  only attack  this  texture,
when it  is  found combined  in  the  different organs with
the other elements of which they are composed, but the
loose cellular texture that surrounds them is equally sub
ject to them; that even,  which, being accumulated in
certain regions, seems entirely insulated  there, is not
exempt from them.   Thus in the white  swellings of the
articulations, in the cancerous affections of the glands and
of the viscera, the lamellated texture is almost always con-
founded  with the diseased parts which it  covers and  is
degenerated like them.   Thus we  find, in the  places
where the cellular texture  is accumulated, schirrous, car-
cinomatous, tubercular and fungous masses, in which this
texture alone appears to be  altered.

         III. Alterations in the Development.,

   The  cellular texture  can itself be developed  preter-
naturally ;  it  is  met with in a great number of morbid
              6 
42      ADDITIONS TO THE CELLULAR SYSTEM.

productions ; many of them are essentially formed  of it.
This  texture takes the place of atrophous organs ; it is
produced on the surface of suppurating wounds, in which
it  constitutes the  membrane  of the fleshy granulations.
The mechanism of its formation  under  these  circum-
stances is far from being perfectly understood, to  say that
it  is an extension, an elongation of the cellular texture
which pre-existed in the part, is not explaining how this
sort of exuberance,  is developed.  Every thing leads us
to believe  that it is a new  texture  formed, as in  the
union of simple wounds, by means of an exudation  of an
albuminous nature  or at least of one capable of concre-
tion.  What is observed in fact in a solution of continuity
which is cured  by cicatrization ? The hemorrhage ceases,
the blood  is replaced by  a  serous fluid,  the wound is
covered by a soft  whitish layer, at first feebly adhering
to it; soon this substance, to  appearance  inorganic, is
penetrated  with vessels, becomes more dense, it cannot
be  separated but with difficulty from the subjacent parts
and it takes all  the characters of  the  membrane of  the
fleshy granulations.  Has  not  this  series of  phenomena
the greatest analogy with what takes place on the surface
of inflamed serous membranes? Do we not  see in both
cases an effusion of lymph capable of concretion, the re-
sult of which  is the production  of  a false  membrane,
which, by  becoming organized, is changed into real cel-
lular texture ? 
ADDITIONS
                       TO THE


NERVOUS SYSTEM OF ANIMAL  LIFE.
          Nerves which the Brain furnishes.

   Page 172.—" The cerebrum furnishes but two nerves,
 the  olfactory  and  optic; .........their softness is greater
 than that of most of the other nerves."

   The  optic nerve is placed at the present day, among
 those of the medulla oblongata.  It derives  its origin in
 fact from the tubercles which surmount the posterior part
 of the tuber annulare; tubercles called quadrigemina in
 man, though there  are but two of them in many animals,
 and the size of which is  such, in many classes,  as birds
 and fishes,  that they might be taken for cerebral hemis-
 pheres.   These tubercles which deserve to be called optic
 rather than the thalami to which  this name has been
 given, are evidently a dependance of the  cerebral protu-
 berance, and not of the cerebrum,  as  some  anatomists
have said.  As to  the olfactory nerve,  its origin is  not 
44
ADDITIONS TO THE
 yet well known.   Animals exhibit it to us coming out of
 an accessory part which their cerebrum has,  from a kind
 of lobe superadded to its hemispheres.  This lobe, some-
 times more considerable than all the rest of the cerebrum,
 is formed by an elongation of the peduncles which extends
 forwards.  But nothing  similar appears to exist in man.
 The olfactory seems to be detached  from the surface of
 the brain itself.  Yet some anatomists say that they have
 traced it further.   M.  Chaussier makes it arise from  the
 corpus striatum, and others have seen it  continued with
 the peduncles.  In this last hypothesis, and by reasoning
 from  analogy, some consider the pulpy swelling of this
 nerve  as  its real  point of origin.  This swelling would
 form  part of the  cerebrum and represent the olfactory
 lobe of animals ; the nerves of this name would only com-
 mence at the ethmoidal canal.

                Origin of the Nerves.

   Page 173.—" It is  clear,  that the nerves  do not arise
 deep  in  the cerebral  substance, at least  in  an apparent
 manner, but take their  origin  from its external surface."

   Accurate  researches have  demonstrated,   1st, that we
 can trace, to a certain depth, the filaments of the origin of
 most of  the  nerves  both  spinal and  cerebral ; 2d,  that
these  nerves do not arise from the medullary substance
which they only pass through, but from the grey substance,
which  is always found  accumulated in the neighbourhood
of the places  where they are sent off, as Vicq-d'Azyr has
already remarked.  These truths  have been  placed be-
yond a doubt by the  recent labours of M. Gall.
   The mass of grey  substance which  occupies the centre
of the spinal marrow forms there on each side, when the 
          NERVOUS SYSTEM OF ANIMAL LIFE.        45

marrow is cut across, two arched striae.  From the median
line, where these striae are united,  they go obliquely out-
wards, one before and the other behind, and are evidently
continued with the anterior and posterior branches of the
spinal nerves.  In other words, this grey substance repre-
sents in the marrow two species of prismatic cords united
at the back by one of  their angles, and continuing with
the nerves by the other two.
   In examining  attentively the cerebral  nerves at their
origin, we perceive moreover more or less distinctly the
grey substance which furnishes them.  Sometimes  this
substance is superficial, as at the origin of the olfactory and
optic nerves, and nothing is more easy than to see the  me-
dullary filaments  separating from it.   Sometimes it is
deeply situated, and it is only by  a careful dissection  that
we can  discover  the  true origin  of  the  nervous fibres,
which, breaking off on a level with the cerebral substance,
seem to arise from  this place.   Sometimes the nerve is
strengthened in  its  course  by the addition of new  fila-
ments  which come  to it from the neighbouring parts of
the  cerebral substance;  this is  the  case  with the optic.
There  exists also some of the grey substance at the origin
of these filaments.
   Nevertheless we ought not to conclude from these facts
that the grey substance produces the nervous  filaments,
and it  is no doubt in a figurative sense that M. Gall has
called  it the originating,  or nourishing substance, or
matrix of the nerves.  The word origin, as Bichat has
observed, must not be understood literally.  Besides, be-
cause the grey substance is met  with wherever the  ner-
vous is continued with the nervous  centres, it does not
follow  from that, that  one is  made by  the  other ; the
union  of these  two substances may  have very different
uses. 
46
ADDITIONS TO THE
                Crossing of the Nerves.

   Page 174.—". I do not  believe that with our present
 knowledge we can explain this phenomenon" (the crossing,
 in  paralysis  from compression  of  the  brain,) " and the
 anatomical opinion pointed out above" (viz. that the nerves
 cross at their  origin) " is contradicted  at the first sight."

   If in fact the crossing of the nerves at their origin has
 been  rather supposed than  seen, it is not so with that of
 the spinal marrow which Petit, Lieutaud, Winslow and
 other anatomists  have admitted.  Raise carefully the pia
 mater which  covers the  extremity of  the medulla ob-
 longata,  afterwards  separate the anterior pyramidal emi-
 nences, and you will distinctly see the  medullary fila-
 ments of the  right  side going  to  the  left,  directed ob-
 liquely towards  the cerebrum ; and  vice versa,  those
 which compose  the  left  pyramid  ascend  and go to the
 right side.  Above  this crossing in the  form of a  mat,
 the pyramids are  united   by  transverse fibres, which
 should not be  confounded  writh  the oblique ones  here re-
 ferred to.
  This arrangement enables  us to explain how the lesions
 which exist above this place, either in the  cerebrum or
 the medulla oblongata, produce paralysis  in the  side op-
 posite to the  affected one.  On the contrary, when the
 spinal marrow is divided transversely and  on one side
 only, the same side is paralyzed, as Yelloly  has  proved ;
 Galen had before noticed this fact.
  It has  been "said that in  some cases, paralysis and the
 eerebral injury which was the cause of it, have been seen
to occupy the  same side of  the  body, the  motions being-
preserved on the  opposite  side.  It is hardly possible to 
          NERVOUS SYSTEM OF ANIMAL LIFE.        47

explain these insulated facts, at least to admit the explana-
tion which M. Gall has given.   This explanation is found-
ed upon this, that among the fasciculi which  go from the
spinal  marrow to the cerebrum, the anterior  pyramids
alone  cross.   Now,   by  supposing  that  the  cerebrum
should be injured in a point where  its fibres  are not con-
tinued  with  those of the  pyramids, the  phenomenon
arising  from  the  crossing will  not take place.   It would
remain  to be known if this exception is met with in the
cases observed ; this has not been stated.

     Chemical Composition of the Nervous System.

   Page 196.—"  This hardening,  the effect  of acids,  of
boiling and of alkohol.........approximates this substance''*
(the cerebral) " to the albuminous fluids.  I 6ay that it
approximates it, for there  are  still  great differences be-
tween them,  of which, I think, we  know but little."

   The  cerebral substance has  been analyzed by modern
-chemists.   M. Vauquelin has found in it,  1st,  two pecu-
liar  fat substances united to a certain quantity of phos-
phorus ; 2d, water which forms 0,80 parts of it; 3d, albu-
men ;  4th, osmazone; 5th, sulphur ; 6th, phosphate of
potash, lime and  magnesia; 7th, some appearances of the
muriate of soda.
   Of the two fat  substances, one is  white,  shining and of
a  soft  and viscid  consistence.   It  is distinguished  from
fat, properly  so called, by its crystalline appearance,  by
the  facility with which alkohol  dissolves it and by the
black  colour  it assumes  when heated.   When burnt, a
charcoal is left for a residuum which contains phosphoric
acid.  It  constitutes  0,45 of the  substance  of the  cere-
brum.   The  other fat substance is much less abundant in 
48
ADDITIONS TO THE
it, and differs from the preceding only in having a red
colour, a strong odour and  taste and  being  still  more
soluble in alkohol.
  The same principles are found in the spinal  marrow ;
the proportion of fat  substance is greater in it; there is,
on the contrary, less albumen, osmazone and water.  The
medulla oblongata exhibits the same differences.
  It is the albumen which predominates in the nerves;
the white and red fat substances  are in very small quan-
tity in them.

       Peculiar Texture of the Nervous System.

  Page 199.—" In general I think that this substance,"
(the nervous) " as well as the cerebral, would be ranked,
if they were deprived of the vessels  that run through
them, rather  among the  fluids than  the solids, or they
would form a medium of connexion between the two."

  We ought  to distinguish in the texture peculiar to the
organization  of the nervous  system, the two  substances
which it contains,  the white and the grey.
  The white or medullary substance  is evidently com-
posed of fibres in  many  parts of the cerebrum ; such as
the corpus  striatum, the corpus callosum, the tuber annu-
lare, the elongations  which it sends to the cerebrum and
to the  cerebellum  and  the termination of the medulla
oblongata.  Except this  small number of exceptions, the
cerebral mass, when cut in  all directions, seems to  be
perfectly homogeneous, and is uniform in appearance ex-
cept  from  the red points which are  the  orifices of the
divided vessels :  there is no very distinct filament  seen
in it.  Yet we shall be compelled to admit the existence
of filaments,  for, if we endeavour to  tear the white sutn 
NERVOUS  SYSTEM OF ANIMAL LIFE.
49
stance, we shall  see that it  resists more in one direction
than another.   But if  instead of thus dissecting the cere-
brum by cutting  it irregularly, we  attempt to  trace the
course of the apparent fibres to its inferior part, by gently
scraping the cerebral  substance in the direction of  these
fibres, we shall soon acknowledge that they extend much
further  than we  at first thought.  We shall see  them
penetrating  the cerebral mass itself, becoming stronger
there and contributing by  their union to form those emi-
nences that are so numerous, those fasciculi  so  variously
formed,  between  which we  do not at first find any kind
of connexion.
   It was by pursuing this'method that Malpighi discover-
ed the real structure of the cerebrum, so well developed
since by Reil, M. Chaussier  and M. Gall.   Nothing  is
easier than to verify the facts stated by  these anatomists,
provided we could have  a brain of a certain consistence,
such as would be that  of a  living animal.  We can ren-
der  it firmer  by  the  means of reagents.   We  cannot
say that  it is  their action  which produces an appearance
of fibres, for  with very dissimilar  liquids,  the results
are uniform.  The following is  the arrangement which  is
observed :
  The fibrous  fasciculi which constitute the termination
of the medulla oblongata, having arrived at the inferior
edge of the tuber  annulare, separate.   The posterior bo-
dies go to the  cerebellum in which they  terminate.  The
anterior pyramidalia and the cords coming from the cor-
pora olivaria, traverse the tuber annulare  by passing above
its  transverse   fibres.  They plunge into  the grey sub-
stance which   they  there  meet with, then come out in
front of the pons varolii, and are extended  on each side,
to form the  peduncles  or crura of the cerebrum ; the me-
dullary filaments  are very distinct in these elongations,
             7 
50
ADDITIONS TO THE
because they  are  mixed  with the grey substance which
insulates them.  These filaments  become  larger,  when
they are extended across the optic thalami and the cor-
pora striata.   Beyond  these eminences,  the  fasciculi
which  come  from the medulla  oblongata  spread out in
each of the cerebral hemispheres; their fibres go  in  all
directions and  extend even  to the circumference of the
organ.   Those  which  occupy the posterior and  superior
part of it come  from the corpora olivaria,  whilst the
pyramidalia form  especially the anterior and inferior part
of the cerebrum.
   On the other hand, the fibres  which unite the  hemi-
spheres at the median line, as those of the corpus callo-
sum, the fornix and the anterior  and posterior  commis-
sures, do not appear to be continued with the  fasciculi
coming from  the medulla oblongata.   Hence  the distinc-
tion of the diverging and the  converging fibres, or appara-
tus of  formation and apparatus of union, (Gall) called also
system of the crura of the cerebrum, and system of the
corpus callosum, (Reil.)  Anatomists are not agreed  re-
specting the origin of the fibres of the second order; per-
haps it differs in each of its parts.
   The  cerebellum  has also  two  orders of fibres.  The
greater part of its mass is derived from those which  come
from the corpora posteriora, and which are much increased
in the  grey substance of these bodies.   Some come from
the  fasciculi  which the cerebellum receives from the
tubercula quadrigemina; they are those which form more
especially the  median lobe,  or  the superior vermicular
eminence, as Vicq-d'Azyr first demonstrated.  Finally
others, analogous to the commissures of  the cerebrum,
unite the two lateral lobes by forming what is called  the
Pons Varolii, whether these fibres arise, as M. Gall thinks,
from the external  grey substance, or whether  they  are 
NERVOUS SYSTEM OF ANIMAL LIFE.        51
nothing but the diverging fibres curved, as is the opinion
of Tiedemann.
  The medullary substance of the nerves is formed, like
that of the  cerebrum, of fibres in juxta-position.  Accord-
ing to the experiments of  Reil, this fibrous  appearance is
not owing to the  presence of the  neurilemas which  can
be destroyed  with acids without altering the filamentous
texture.
  The white  substance, examined  in the spinal  marrow
is also composed of  filaments ; Vieussens was among the
first who noticed this arrangement, since very well ob-
served by Monro and M. Gall.  The arrangement of the
fibres is here very remarkable.  The pia mater is buried
in the anterior median furrow, and continued behind into
the substance of the spinal marrow, almost to its posterior
face; from  each  side of  this elongation many grooved
filaments are detached, directed from above  below, which
contain the medullary substance.  By subjecting the spi-
nal marrow to the action  of  the alkalies, this substance is
destroyed,  and the membranous tubes remain  untouched.
There  is then a great analogy in this respect, between the
structure of the spinal marrow and that of the nerves ; the
pia mater performs here really the part of the neurilema,
If the  consistence of the  spinal marrow is  increased  by
acids, the fibres which compose it  are easily distinguished.
Most of them are longitudinal, and represent an infinite
number of small lamina, formed themselves of delicate
filaments;  some  are  transverse.    These  last  are seen
especially in  the  depth  of the anterior median furrow ;
the posterior, on  the contrary, exhibits only longitudinal
fibres.   All these fibres unite and anastomose in different
ways, as the nerves do.
  The grey substance does not form like the white a con-
tinued  whole ; sometimes exterior to this last, sometimes 
52
ADDITIONS TO THE
 intermixed  with its  fibres,  it  is  in general met with,
 wherever the medullary filaments  become  larger.   It  is
 found in the whole circumference  of the cerebrum,  and
 forms what is called the cortical substance ; it composes
 at the base of this viscus many masses  which have  been
 compared to  ganglions.  It occupies  the centre of the
 spinal marrow ; it has been said that the nervous extremi-
 ties are provided with it, but this has by no means been
 demonstrated.
   The colour of this substance is generally of a brownish
 grey, in some parts yellowish and even black; the diver-
 sity  of these shades is attributed to the greater or  less
 quantity of  blood which it  receives.   Its density is  less
 than  that of the white substance.   Its structure is but
 little  known ; some have admitted  that  there were fibres
 in it; Vicq-d'Azyr has traced filaments coming from the
 medullary  substance.   It contains  many  blood-vessels,
 more even than the white substance ; but it is not entirely
 formed  of them,  as  Ruysh thought.  His belief arose
 from  the fact that by washing this substance, after having
 injected it, there was finally nothing left but vessels;  but
 it is  evident, that in this case,  as Albinus  observes, the
 washing takes avVay every thing that is not vascular or
 capable  of injection.
  The nervous texture, examined by the  microscope ap-
 pears to be composed of globules ; this has been observed
 a great number  of times.   Prochaska, Wenzel, Barba,
 and recently M. Bauer have paid particular  attention to
 these globules.   In order to see them,  it is necessary to
mix with water a small quantity of the white substance
and place it in the focus of a strong  lens.  Their  size has
been very differently estimated ; it has been  compared, as
well as their  appearance, to that of the colourless globules
which are found in  the blood.  Prochaska  thinks them 
           NERVOUS SYSTEM OF ANIMAL LIFE.        53

 smaller than those of the blood.   The Messrs. Wenzels
 brothers think that  they  are hollow.  They  are not de-
 stroyed by maceration nor by reagents.  Their union ap-
 pears to be intimate ; we are ignorant of the mode of it; it
 is supposed that there exists between them a very delicate
 cellular texture, containing vessels; others  have thought
 that they saw there a fluid and viscid matter.   Sometimes
 arranged in a row, they form straight parallel lines ; some-
 times they are found confusedly heaped together, as Pro-
 chaska says he has observed in the grey substance.  It is
 no doubt from this difference that  Carus, rejecting the dis-
 tinction of white and grey substance, says that the organ-
 ization of the nervous system exhibits but  two essential
 modifications ; in the  one, which constitutes the  gangli-
 form or central masses, the nervous substance is composed
 of irregularly scattered points; in the second,  which com-
 prehends the nerves, they are regular and constant  lines.
 From this difference of organization, he deduces the dif-
 ferences of action of the twro systems, the first being able
 to act by irradiation, whilst the other is limited,  in this
 respect, to the direction of its length.
   The colour of the grey substance appears to reside less
 in the globules themselves, than in the species  of soft
 cellular texture which  separates them.  To  remove the
 colouring matter from this substance, it  is merely neces-
 sary to put it in tepid water in thin slices.   Sublimation
 produces in part the same effect.   This  matter does not
 then seem to be inherent  in the globules.

        Development of the  Nervous Centres.

   Page 237.—" The extreme softness of the brain ren-
ders its dissection very difficult in the foetus." 
54               ADDITIONS TO THE
   Tiedemann has succeeded in overcoming this difficulty.
This author has traced all the changes of the development
of the encephalon, and has described them with great
precision.  Carus, Doellinger and  Ackermann, had pre-
viously stated some facts  relative  to the development of
the nervous system.  M.  Serres  has  recently been  en-
gaged in  this subject.
  The brain scarcely exists in  the  beginning;  in an em-
bryo of six weeks, there  is found only a flattened cord
which  represents the spinal marrow,  and the superior
extremity of which is  slightly enlarged.
  In pregnancy of two months, the brain is still but very
little developed compared with the spinal marrow; it is
then composed, 1st, of the cerebellum,  the transverse ex-
tent of which is considerable; 2d, of the cerebrum, which
is very small; 3d, of  a third portion placed between the
two first, and the size  of which exceeds that of the cere-
brum ;  this  part  appears to correspond  to  the cerebral
protuberance, or more exactly  to the tubercula quadrige-
mina.  M. Serres has  ascertained that it is formed in man
and  animals, before the  cerebrum and cerebellum, and
immediately after the  spinal marrow.
  The relative dimensions of these organs  afterwards
change.  The cerebrum grows more and more ; towards
the fifth month, it already covers a part of the protuber-
ance ; at the sixth, it  extends even upon the cerebellum,
which it  gets beyond at the seventh.   The other parts on
the contrary increase less in  proportion, especially that
which corresponds to  the protuberance.
  The whole encephalon is divided at first into two parts
by  a longitudinal furrow ; this arrangement is observed
in foetuses of seven months.  The two  halves  afterwards
approximate  and finally  unite, except in some  places,
where the interstices form cavities ; so that at three months 
          NERVOUS SYSTEM OF ANIMAL LIFE.        55

we discover instead of a  longitudinal division,  1st, the
third ventricle ;  2d, the aqueduct of Sylvius which is, at
this period, a great cavity continuous with  the  middle
ventricle ; 3d, the fourth ventricle. Afterwards the cavity
of the aqueduct is gradually contracted ; it is nothing but
a canal towards the seventh month.  The two other cavi-
ties undergo  no ulterior changes  but those which belong
to the development of the parietes.
   In the first periods of gestation,  the conformation of
the cerebrum is very simple ; there then exists but  the
base of this viscus, and that even  is very imperfect.  We
see in a foetus of seven weeks only the thalami nervorum
opticorum, the  corpora  striata are hardly  visible ; a sort
of membranous part seems to indicate the place  of  the
hemispheres.
   It is in fact under the form of a membrane that each
hemisphere is developed ; this membrane,  originating at
the base is bent before  and behind, as  it  is  seen  at  the
ninth  week, and extends to  the  corpora striata and  the
thalami nervorum  opticorum ; the space which remains
belowT  them  constitutes the  lateral ventricles.   The  an-
terior lobes appear  first; they are very visible  at three
months.   The  corpus  callosum  is formed  almost at  the
same time, by the  junction of the two membranes of the
hemispheres; it occupies at first  only their anterior part,
and is extended backwards as they grow ; at six months
it only extends half their length.   The cornua Ammonis
appear with the corpus callosum, as well as the fornix,
the mamillary eminences, the posterior commissure, and
the peduncles of the cerebrum, shortly after is discovered
the hippocampus minor and the  groove which gives rise
to it, the pineal gland and its peduncles, then the ante-
rior commissure, the septum lucidum and its cavity, which
then communicates with the  third ventricle, between  the 
56
ADDITIONS TO THE
two pillars  of the  fornix ; in the last place,  the semi-
circular band, the plexus choroides and the infundibulum ;
this successive evolution is completed towards the seventh
month.
  All  these parts  have not the same appearance in the
different periods  of their development; thus the fornix
is at first composed of two cords insulated in their whole
extent; thus the corpora striata are for a long time larger
than afterwards  and of a different form.  At the third
month, the lateral ventricles are open at their internal and
posterior part; we  can, even  towards the fourth month,
penetrate  into their interior by turning back  the mem-
brane which forms them.   At the fifth,  their extent is
considerable, owing to the small  degree of thickness of
their  parietes ;  they  progressively  diminish, as  these
parietes are  developed.   The  surface of the cerebrum is
smooth in the first months ;  soon  the  fissure of Sylvius is
visible, some inequalities appear, and the circumvolutions
are  formed at  the seventh or eighth month.
  The cerebellum, in an embryo  of seven weeks, appears
like a fine lamina,  stretched horizontally from each  side
of the fissure which divides the encaphalon at this period,
and continuing on the one hand with  the spinal marrow,
and on the other with the cerebral protuberance.  Tins
lamina, bent backwards, forms towards the fourth month
a great cavity  continuous with the  fourth ventricle ; it
afterwards becomes  thicker and  the cavity diminishes.
This is reduced to the fourth  ventricle towards the fifth
month ; transverse  furrows  then  divide the cerebellum
into five lobes.  The structure of this viscus  is more and
more  developed.  The  lamina are very  distinct at the
seventh month.
  The cerebral protuberance would be better called in the
beginning the mass of the  tubercula quadrigemina ; its 
          NERVOUS SYSTEM OF ANIMAL LIFE.        57

inferior part or Pons Varolii is wanting, there only exists
the lamina which is afterwards surmounted by the tuber-
cula.   This part is hollowed  out from the aqueduct or
cavity of Sylvius,  and exhibits  a groove which is the
trace of the division which is early observed.  The tuber
annulare, properly so called, begins to appear in the course
of the fourth month, but its development is  not complete
till the seventh ;  it is also at this period only  that the
tubercula appear.
  The spinal marrow forms at first a species of ribbon,
divided by the common  fissure  and occupies the whole
length of the vertebral canal, extending to the os coccygis.
In the third month, its edges turn over behind and unite,
by which means a canal is  formed  which is continuous
with the fourth ventricle.  At twelve weeks, the termi-
nation  of the  medulla  oblongata is very evident; we see
there the posterior pyramidalia which are continued with
the cerebellum and the anterior ones making a continua-
tion with the peduncles of the cerebrum.   It is at the
third month, according to M. Serres, that the medulla is
contracted and reaches by  degrees to the  level of the
second lumbar vertebra.   At the  fifth,  we distinguish the
cervical and  lumbar  enlargements as  well  as the  cauda
equina; the canal of the medulla  still  evidently commu-
nicates with the fourth ventricle.
  Such are the principal changes which take place in the
conformation of the encephalon.   Those which it expe-
riences in its texture are not less  remarkable.
  All is fluid and  homogeneous in the beginning.  The
white substance afterwards becomes more  distinct.  Its
fibrous structure  is early manifested ;  the  interlacing  of
the pyramidalia is seen  at the eighth week, according to
M. Serres.  Tiedemann has seen at  the fourth month
fibres in these pyramidalia, and shortly after in the fasci-
              8 
58
ADDITIONS TO THE
culi of the olivaria; these fibres can  be traced in the tha-
lami nervorum opticorum and in the corpora striata ; they
extend out in  rays to  form the membrane of the hemi-
spheres.   These diverging fibres become more and more
evident; at  the sixth  month,  they are  almost naked on
the parietes  of the lateral ventricles.  At the same period,
the cerebral  substance has appeared,  through the micros-
cope, to be composed  of globules immediately below the
pia mater, and of fibres  lower down.  At the seventh
month, a section  of the ventricles exhibits very evident
layers of radiated fibres.  New ones are afterwards  pro-
duced which  form the  circumvolutions ;  they seem to
arise from the external pia mater and are joined at a right
angle to the first; these are called the  converging fibres.
At the ninth month, the organization is completed.
   The grey substance does not appear till a  long time
after  the white.  It is not until from the sixth to  the
seventh month that the cords of the corpora olivaria form
real eminences, by the development of this substance in
their  interior;  the  pyramidalia are  enlarged  a month
sooner.   In  the last periods of gestation, the canal of the
spinal marrow  is also  filled with a  grey substance ;  the
same  substance is developed in the circumvolutions of the
cerebrum, in the cerebellum, &c. ; its  colour is not very
evident in all these parts till the ninth month.  M. Serres,
as well as Tiedemann,  thinks, that  the white substance
arises before the grey in the spinal marrow ; but it is not
the same, according to him in regard  to the  cerebrum;
he considers the optic thalamus and  the corpus striatum
as entirely formed of  grey substance in the beginning ;
the white is not developed till afterwards.  The grey and
white subst?inces  are  always preceded  in  their develop-
ment, by that  of the red vessels in the  places where they
are produced. 
NERVOUS SYSTEM OF ANIMAL LIFE.        59
             Development  of the  Nerves.

  Page 237.—" The nerves of animal  life have a devel-
opment proportional to that of the brain."

  This relation is very different in  the beginning, for we
distinguish the spinal marrow and the brain, whilst most
of the  nerves are wanting, on account of the late develop-
ment of  the other systems.  We know not  if it  be  the
same with the heart and  the digestive canal, which are
formed almost as soon as the nervous system. M. Meckel
thinks that the nerves of  these organs, like those of the
other parts, do not appear until after the nervous centres.
Yet  the  great sympathetic  appears to  exist very  early,
and is  developed if not sooner, as Ackermann  thinks, at
least at the  same time as the  brain and spinal marrow.
Another exception to this rule is, that we find, in a month
after conception, the intercostal nerves as well as the ver-
tebral ganglions ; now, neither the  brain nor the marrow
are distinct at this period.   Perhaps the filaments of the
great sympathetic being more transparent escape observa-
tion.   This  nerve  is  found in foetuses which  are born
entirely destitute of all the parts  of the encephalon.
  In a foetus of  three months is  seen distinctly the optic
and olfactory nerves.   In  the  following month the fifth
pair  is visible.   At the seventh, the origin of all  the
nerves is seen perfectly well.  The olfactory nerves are
at first very large,  they begin to diminish at  the sixth
month.  The  spinal nerves  are, like  the  cerebral, very
distinct at their origin before  the  grey substance is  dis-
coverable, (Tiedemann.)
  The texture of the nerves does  not become apparent,
until their vessels are developed. 
60
ADDITIONS TO THE
MORBID ANATOMY OF  THE NERVOUS SYSTEM OF  ANIMAL
                         LIFE.

       I.   Alterations in the External Forms.

   Organic diseases often increase the size of the nerves,
as Reimarus has observed with regard to white swellings.
Neuralgias are  sometimes accompanied with  the same
alterations.  Cotugno has found the sciatic, in the neural-
gia of this name, as if it were infiltrated with  gelatinous
matter.  Fat also may  accumulate  between  the  nervous
fibres.  A sort of atrophy of the nerves  is on the contrary
the result of  some paralyses or of pressure too long con-
tinued ; thus in  amaurosis, the optic nerve  is  often har-
dened like horn, and gradually reduced to its neurilema;
thus various tumours produce atrophy of the nerves which
they compress.   The brain appears to have  experienced
a diminution of  size in the cases stated by Littre and Sa-
batier, in which after a powerful concussion, this viscus,
they assure us, no longer filled the cavity of the cranium.
M. Cruveilhier has seen the same thing in the dead body
of an  idiot.
   The nerves have  sometimes appeared to  be less con-
sistent than in the natural state.   Weinhold, as cited by
Hufeland, has found in them after typhus, a peculiar soft-
ness and flaccidity.   They exhibit, it is said, this altera-
tion in dropsies and fatal hemorrhages.
   The brain presents the two extremes  in relation  to its
consistence ; its  hardness is  seen in mania, idiocy and
epilepsy;  its softness, observed at first  in the  same cir-
cumstances, has  been since seen in  ataxic and  adynamic
fevers and in hydrocephalus.   M. Rostan has given some 
          NERVOUS SYSTEM OF ANIMAL LIFE.        61

new details upon this last alteration and upon the disease
which results  from it.  In the cases which  he has ob-
served, the softening varies much in relation to its extent,
depth, intensity, colour of the  cerebral  substance, &c.
M. Lallemand has also described  this alteration.
   The spinal marrow loses its consistence in spina-bifida.
Softness of the  marrow has  recently been met with by
M. Scipio Pinel, in cases where it appeared to have pro-
duced peculiar symptoms.  Frank  has  found this organ
hardened.
   Tumours, such as aneurisms, situated upon the course
of the nerves, may displace, distend and flatten them.  It
is known how  they yield under  these  circumstances.
Perhaps their elongation may be in great measure attri-
buted to the kind of unfolding which they undergo.  The
nerves are in fact folded in the natural state ; their sur-
face is, at it were, wrinkled ; by examining it attentively,
we can discover there an innumerable quantity of small
striae, transverse in most, oblique in others, interlaced in
some, forming zig-zags, spirals, &c.  These striae are re-
markable for their yellowish or fawn colour, which forms
a contrast with the pearl white which the  nerve preserves
in their interstices.  This is at first viewr so striking, that
we only see at first a multitude of white threads, arranged
precisely like the striae ;  the deeper  colour of these last
prevents them from fixing the attention so much.  Now
these striae are effaced by extension and reappear when it
is taken off.   The same thing then should take place in
the cases of which we have spoken.
   The brain and spinal marrow are exposed to compres-
sions, which alter more or less their form.  The marrow
in particular  undergoes at times remarkable  bendings;
its functions are not always deranged by them.  The  form
of the brain also experiences very great  changes in hydro-
cephalus. 
62
ADDITIONS TO THE
        II.  Alterations in  the  Organization.

  Inflammation of the nerves is a  very rare disease.  Can
we give this name to the sanguineous engorgements, vas-
cular dilatations,  which their  surface exhibits in certain
cases, in typhus, for example ? To be certain of the na-
ture of these engorgements, it is necessary to destroy the
neurilema by an acid, and observe what is then the colour
of the medullary  substance.   Reil, who has followed this
course in many cases, has found the nervous  medulla of
a red colour and evidently inflamed.  Suppuration, gan-
grene and ulceration can affect the nerves, but they never
do primarily.   The  brain, on the  contrary, is often the
seat  of purulent  collections;  gangrene sometimes  seizes
upon it, as is seen particularly after wounds of the head,
when this viscus  is  injured or merely laid bare ; we re-
move it then by  spoonsful, in the form of an extremely
fetid, grey sanies.  False membranes are produced  in the
brain, especially upon the parietes of the abscesses which
occupy its interior.   They are susceptible of being organ-
ized and becoming vascular.
  The  mode of  reunion  of the  nerves, when  they are
divided, has been a subject of discussion.  Arnemann has
described  it with much  care.  Shortly after the division,
the superior end swells  at its extremity, and forms a kind
of greyish knot, elongated and  very hard ; the inferior
swells also but less, then both unite and their separation
disappears.  The knot continues and often even acquires
a consistence almost  cartilaginous.  The portion  of the
nerve  which  is  below also  undergoes  some  changes,
though all observers are not agreed upon  this point.  In
general it becomes  more slender, is withered, as it were, 
NERVOUS SYSTEM OF ANIMAL LIFE.        63
its colour changes  and its  folds are effaced.  As to the
nature of the cicatrix, most authors think it nervous, and as
such, capable of re-establishing the continuity of the nerve
in relation to its functions.   Haighton has even made ex-
periments upon this subject, which appear to be decisive.
After having cut in a great number of dogs the two nerves
of the eighth pair, either at the same time, or one after
the other, but with only a few days between, and having
thus ascertained that death was uniformly the consequence,
he allowed in another  dog  six weeks to elapse between
the section  of  the two  nerves.  The  animal  recovered
perfectly.  We may conclude from  this, either that the
cicatrix of the first divided  nerve transmitted the  nervous
influence, or that  the  functions  of this nerve were  re-
established between the first and  second  operation, by
means of anastomoses.  To  remove  every kind of doubt,
the two reunited  nerves were cut a second time in  the
same animal  and he died.  Then it was by  means of the
cicatrix that he had lived.  Arnemann denies to the cica-
trices of the  nerves the property of the  nerves ; they are,
according to him,  purely cellular, and when the functions
of the nerve are re-established, it is because there is an
immediate reunion  between the  two  ends; but  when
these ends are  separated, or there is a loss  of  substance,
he denies that  a regeneration can  take  place.   The knot
which is produced appears to him to be incapable  of re-
placing the nervous substance; he has seen it arise from
the cellular texture and only gradually unite with the two
ends of the nerve.  Yet Fontana,  Michaelis and  Mayer
say, that they  have traced nervous  filaments through the
regenerated portion.   These filaments are evidently con-
tinued  with the  nerve.  Til. led  with nitric acid, far
from being  destroyed by it, they  are hardened,  like the
medullary substance under similar circumstances, (Mayer.) 
64
ADDITIONS TO THE
Now these physiologists have removed one,  two, six
lines, and even an inch of the length of the nerve.
  In amputations, the superior  end, which forms part of
the stump, swells as in the preceding case.  M.  Lobstein
has given new details upon this fact, which had been ob-
served by Vanhoorn.
  Lesions  of the brain appear, like those of the nerves,
to be followed by a sort of regeneration.  Solutions of
continuity of another kind have, moreover, their seat in
this viscus.  These are the internal lacerations, in conse-
quence of which the blood is effused either in the cerebral
substance, or in the ventricles;  concussions of the brain
and apoplexy offer  examples of them.   The  blood then
becomes  a foreign body,  whose presence occasion serious
difficulties.  These  difficulties  should also be in  part at-
tributed to this, that the cerebral substance is disorganized
in a greater or less extent; its colour is a yellowish red,
and its texture is  softened.   When  death is not the con-
sequence of it, a membrane is formed around  the  blood,
this  fluid is absorbed, and  there remains only a serous
cyst, which also  finally  disappears.   The spinal marrow
is likewise  liable  to  experience this alteration ;  it was
converted into a sort of  porridge infiltrated with  blood,
in a case observed by M. Gaultier de Claubry.
  The nerves are hardly  ever ossified.  The  brain is so
sometimes ;  various instances of which are found  in au-
thors.  They are almost  always osseous productions, for
the  most part loose, rarely adhering closely to the cerebral
substance.  Tumours, which seem to belong to the fibrous
or cartilaginous textures,  are developed in the nerves, the
brain and even  the spinal marrow.  They are hard, grey-
ish and separate the medullary fibres, which take no part
in their development.  M. Dubois and Home have extir-
pated these tumours.  Some refer them  to the cancer of 
          NERVOUS SYSTEM OF ANIMAL LIFE.        65

the nerves.  Cysts  are formed  in  the brain ; we have
already pointed out one of the circumstances under which
they are produced.  They are often taken for hydatids.
These  are rare in man, though they are sometimes found.
  The scrophulous affection is the most common  in the
brain.  It appears under  the  form of tubercles of very
various size, round, greyish or yellow, soft  and brittle,
the number of which is sometimes very considerable.  A
cellular membrane surrounds them.   Cancer of the brain
has also been observed.   Finally M.  Meckel  speaks of
fungous and spongy tumours, analogous to the productions
called  erectile, and which have their  seat  in this viscus.
They are extremely rare in it.   The  nerves are  foreign
to almost all these alterations.

        III.  Alterations in  the Development.

  Clarke  has given, in the Philosophical Transactions,
the description of a foetus so  imperfect,  that  it had no
nervous system.  It is the only fact of the kind  known.
We often meet with acephalous foetuses, or rather aence-
phalous ones, that is to say, destitute of a part or of the
whole of the brain.   The spinal marrow exists in the
greatest number of cases,  but in some it also is wanting.
Examples of this last kind are cited by M. Lallemand in
his inaugural dissertation.   I have myself seen  some.  In
these cases,  the peculiar membrane  of the spinal marrow
forms the parietes of a cavity which contains a liquid, and
the nerves are implanted  as usual  into  this membrane.
Otto, (Treatise on Morbid Anatomy,) mentions many
cases in which the optic nerve and other nerves of the
senses were  wanting  in  individuals  destitute of sight,
hearing,  &c.; the rest of the nervous system  was as in
the natural state.
              9 
66
ADDITIONS, kc.
   Anomalies are quite rare in the nervous system, espe-
cially in the portion of it which belongs to animal life.
Yet the brain  sometimes exhibits an inequality in the size
of its lobes.   Bichat was himself a remarkable example
of this.   Hydrocephalus is most often a congenital affec-
tion. The canal of the spinal marrow sometimes continues
until after birth, as M.  Portal  and others have  seen  in
hydrorachitis.   The nerves vary  a little in their distribu-
tion, though it is more uniform  than that of  the arteries.
  The nervous texture is never preternaturally produced,
if  it be  not in the case  of the  wound of which we have
spoken above. 
ADDITIONS
                       TO THE


NERVOUS SYSTEM OF ORGANIC LIFE.
        Insulation of the Great Sympathetic.

   Page 252.—" It is evident that a  line of demarcation
separates the nerves  of the  ganglions and  those of the
brain, and that the method is inaccurate which considers
them  as forming a single  nerve, arising by some origin
from this last."

   The great sympathetic has always been a subject of dis-
cussion among anatomists. Haller, Zinn, Scarpa and Legal-
lois have maintained, that it depended on the brain and the
spinal marrow, like the other nerves, and that, like them,
it only transmitted an influence which it  receives from
these parts.  Many other physiologists, on the contrary, 
68
ADDITIONS TO THE
think that this nerve  is insulated, by its  arrangement as
well as by its action, from the rest of the nervous system.
Authenrieth makes it come from the general nervous sys-
tem ;  but he supposes that as  its  filaments  pass  through
the ganglions, they are less and less subjected to the cere-
bral action.   According to Reil, the great sympathetic has
only  filaments of  communication  and  no origin,  but  it
enjoys the  property  of a semi-conductor.    Gall, like
Bichat, makes a multitude of insulated systems of it, which
arises from the  manner in which  he has considered the
nervous  system in general.  Finally J.  F. Meckel has
adopted a sort of mixed opinion  according to  which the
great sympathetic, though insulated, may depend, to a
certain extent, upon the central organs.
   It would be superfluous to give  in detail here the rea-
sons alleged for and against these opinions ; we shall con-
tent ourselves with pointing out the principal.  Nothing
prevents us  from calling, in the great sympathetic  nerve,
points of origin, the points of communication of this nerve
with the spinal  marrow and  the  brain,  if we recollect
what ought  to be understood by the term origins  in the
nervous system ;  they are the central  extremities  of the
nerves,  those which are the nearest the nervous centres.
All that has been said  to prove  that  the  ganglions are
these centres, only shows that there are great  differences
of organization  in the great  sympathetic and the other
nerves.   It  is unimportant  whether  this  series of gan-
glions and intermediate cords  is considered as  a  single
nerve, or as so many insulated parts, united  by anasto-
moses.   But it is not so, to know if this system be really
independent of the cerebral, or if, as Legallois  pretended,
it be  on  the contrary  from this last that it  derives all its
influence.  We  know the  experiments of  this physiolo-
gist upon animals from which he removed the brain and 
          NERVOUS SYSTEM OF ORGANIC LIFE.       69

afterwards supported life by means of artificial respiration.
The destruction of the spinal marrow constantly produced
death by the sudden cessation  of the pulsations of  the
heart.   When the spinal marrow was destroyed only in
part, the pulsations were only weakened, cutting off'  the
limbs did not occasion  the blood to  flow, but life still
continued.  Legallois concludes from them, 1st, that the
heart receives the principle of its action from all the points
of the spinal marrow, through  the medium of the great
sympathetic ; 2d, that the integrity of the spinal marrow
is indispensable to the functions of this  last.   But we
have seen  monsters born  without a spinal marrow,  and
yet they lived in the womb of the mother.  Dr. Wilson
Philip having repeated the experiments which we have
just cited, found that the pulsations did not cease imme-
diately  after the spinal marrow  had been removed ; they
ceased quicker when it  was violently torn out than when
it was taken away with care.   The animals, subjected to
these experiments,  resist  also  in general  so  much  the
more in  proportion  as they are younger.  Finally, in
many fishes, carps in particular,. Mr. Clift  has seen  the
pulsations of the heart continue notwithstanding the lesion
of the spinal marrow.  We ought then to have regard, in
the conclusions which we draw from this sort of experi-
ments, to the age  and species of the animal.   We may
apply to  the spinal  marrow, in this last respect, what is
elsewhere said of the brain ;  it is, that in  the inferior  ani-
mals, the centres are much less  necessary to the action of
the rest of the norvous system.   Their less importance in
animals accords with their less development.   So in man
and the  superior  animals, the great sympathetic depends
so much the less  on the brain and the spinal marrow, as
these parts are themselves less developed, as,  in a word,
the individual is younger.   It is in this way, and  not in 
70
ADDITIONS TO THE
an  absolute manner, that we should resolve the question
proposed.

             Structure of the Ganglions.

  Page 258.—" I  think then  by  admitting,  even to  a
certain extent, the internal arrangement that this author
(Scarpa) has observed in the ganglions, we cannot describe
these organs in the point of view in which he has present-
ed them."

  The observations made  by Scarpa have been repeated
in our time.  The ganglions are composed, as this anato-
mist has demonstrated, of  two very different substances,
before pointed out by Winslow.
  1st. It is almost always  easy to trace in the ganglions
the nervous filaments which  emanate from  them ;  these
filaments preserve  in  them  their cylindrical  form, and
white colour, and are easily distinguished from the non-
medullary substance, in which they are, as it were, buried.
It is often sufficient, according to the remark of Haase, to
cut  a ganglion to perceive many small white points, which
are  nothing but  the extremities of the divided nervous
filaments.   These  filaments frequently  anastomose.  In
the  ganglions situated  in the  course of a single nerve,
their direction is  parallel to that  of the nerve itself; when,
on the contrary,  many nerves  unite to form a  ganglion,
there is  nothing uniform ; the medullary filaments  are
seen interlacing  in all directions, and  thus  establishing
numerous communications between these nerves.  Hence
the  ganglions of the first species are  elongated and usually
oval, whilst those of the second have a much more irreg-
ular form. 
          NERVOUS SYSTEM OF ORGANIC LIFE.       71

   2d.  The peculiar substance of the ganglions  is soft,
 pulpy, like albumen or gelatine, of a reddish grey, some-
 times yellowish, lodged in the  interstices of a very deli-
 cate cellular texture.   It is separated with more or  less
 ease from the nervous filaments which it surrounds;  this
 separation is made  with difficulty in the ganglions of the
 great sympathetic ; the medullary filaments are very soft
 in them and almost semi-fluid at their circumference, so
 that their external  layers  are confounded  with the grey
 pulpy matter of which we are treating.  The  plexuses
 exhibit nothing similar to this substance ; it is  this which
 distinguishes them  essentially from the ganglions.
   It  has  been thought that the grey substance  of the
 ganglions was the same with that  of the brain ;  that the
 use of both was  to strengthen the white substance of the
 nervous fibres.  If we examine  comparatively  a ganglion
 stripped of cellular  texture and a portion of brain in which
the grey  substance predominates, we shall see that  this
 resemblance does not exist.  Without speaking of their
 dissimilar appearance or of  the physical  characters which
 distinguish them, the manner in which they are affected
 by  the various reagents establishes  very striking differ-
ences between these two textures.  This is a fact already
recognized by Bichat.   The experiments of Wutzer leave
nothing to be desired upon  this  subject; the following is
an extract from the comparative table which he has given
of the chemical properties of these two  substances in his
Treatise de  Gangliorum Usu et Fabricd. 
72
ADDITIONS  TO THE
 Treated with
cold concen-
trated   nitric
acid,
              f  The one, furnished by the cervical or semilunar gang-
               lions, taken from an adult, stripped of their cellular tex-
               ture and washed in distilled water,  experiences the fol-
               lowing phenomena ; 1st, it  undergoes the horny harden-
               ing; 2d, at the end of eight days, the horny hardening
               continues, the matter blackens, and gives, if  agitated,
               and afterwards left to deposit a friable precipitate, in
               which there is still here  and there discovered an appear-
               ance of  structure ; 3d,  at the end of a longer lime,
             ■^ putrefaction renders it  liquid, but  it exhales  no other
               odour than that of the acid.
                 The other, taken from parts of the cerebrum or cere-
               bellum formed of three  quarters or  nearly of grey sub-
               stance,  1st, is hardened without the horny hardening;
               2d, diminishes a little,  and takes  the  consistence of
               curd ; gives, after having been mixed with the liquor by
               agitation, yellowish albuminous  flakes  which  swim;
               3d, the odour of  the solution  has something similar to
              j.that of rancid  oil.

                 The ganglion is dissolved; the liquor  is only a little
              I turbid;  by cold a  slight precipitate is  formed and  a
               small quantity of the matter comes  to the surface.
  .«jr iuc oaiuc j   rpjje cerebra] substance is dissolved but in part, a cer-
         °'    tain quantity swims upon the liquor; the solution pre-
               serves its transparency after it is cold, though an infinite
              jiumber of medullary particles is seen suspended in it.

              f  The first is  softened a little ; its  white filaments dis-
   By a solu- ] appear;  its solution is slow and imperfect.
tion of caustic ■{   The second is dissolved more  easily ; one  tenth of
potash cold,   f the matter floats upon  the  liquid,  and  does  not mix
              l.with it.

                 In one, some filaments remain insoluble; cooling is
  By a solu-  followed by a deposition formed of  globules of a deep
tion of boilingl red.
caustic   pot-'   In the other,  the  solution is  almost complete; by
ash,            cooling, the surface of the liquid is  covered with flakes
               of a yellowish white.

              f  The  substance of the ganglion  is  contracted, then
   R  h Tn  ! dissolved to two thn"ds ;  the liquor is turbid.
  rohol        i   ^e cereDral matter bardens, and afterwards experi-
              j ences changes observed by M. Vauquelin ;  albumen is
              (^obtained from it.

  Finally, different reagents, which have no action separately on  the
acid  solution of these substances give precipitates when employed to-
gether ; the alkaline solution  presents the  same phenomenon,  when
treated  with the muriatic acid, and then with nut  galls.  These  pre-
cipitates furnish new characters by the differences  which they exhibit in
their properties, according  as  they belong to the cerebral substance or
to that of the ganglion.
alkohol, 
NERVOUS SYSTEM OF ORGANIC LIFE.
73
   No doubt a good analysis of the ganglions remains to
 be made, in order to know precisely the difference which
 exists between  their substance and that of the brain, but
 these data are sufficient to prove  that these differences are
 real.
   According to Scarpa, the peculiar substance of the gang-
 lions is replaced by  fat in very fat subjects ; it  appears
 that  this is not always so.  When the  corpulency has
 been  the greatest, there  has only been found some fatty
 vesicles  under  the peculiar membrane of the  ganglions
 (Wutzer).  We  can conceive that if fat  should accumu-
 late there, it would compress  the grey matter, and make
 it disappear in whole or in part.


                 Uses of the Ganglions.

   Page  273.—" Scarpa has collected the  opinions of all
 who  have preceded him,  together with  his  own,  upon
 the uses of the ganglions.  I refer to what he has said
 upon this subject."

   We can divide into two classes the opinions of physio-
 logists upon the uses of the ganglions.
   Some attribute to them purely mechanical ones, as that
 of facilitating the distribution  of the nerves, of effecting
 the intimate mixture  of the nervous filaments, of  favour-
 ing their union, separation, &c.   Meckel the elder, Zinn,
 and Scarpa are of this number.
   The others  allow  them  functions  of a higher  order,
essentially vital, and think that they are designed to mo-
derate and  even destroy the  reciprocal influence of the
brain  and the nerves.  They thus explain how the organs
of the internal life are to a certain extent independent of
              10 
74
ADDITIONS TO THE
the cerebral action,  and how the brain in its turn per-
ceives  with difficulty  the  impressions  made  upon these
organs or upon their nerves.  In a word, the two  lives
do not differ more than in their nervous systems.
  This idea, obscurely stated in the writings of Willis,
F. Petit and  Bianchi  belongs truly to Johnstone ;  most
modern  physiologists   have  adopted   it.   It  must  be
acknowledged that it  accords very  well  with  what we
know  of the  structure of the ganglions, and  nothing
seems  more capable of breaking the nervous force than
these medullary  interlacings  surrounded  by a substance
wholly different  from that of the nerves.   It is  asked
nevertheless why some impressions  are transmitted not-
withstanding the obstacle which the ganglions present to
them ; why the vertebral  ganglions  do not  perform in
respect to  the  parts which receive their nerves of  them,
the same uses as the ganglions of organic  life.  The first
objection has been answered by saying, that the ganglions
are imperfect conductors, that they insulate sufficiently to
arrest ordinary impressions,, but that very acute ones pass
through  them.   Wutzer has seen the action  of the gal-
vanic pile upon the  lumbar ganglions cause very severe
pains, accompanied with convulsive motions, whilst a less
degree of irritation produced nothing similar.   As to the
second  objection,  it can hardly be combatted except by
considering the differences of structure  which the  gang-
lions of the spinal nerves exhibit compared with those of
the great sympathetic,  differences which ought to produce
a difference in the functions.
  To concentrate  the nervous power, to strengthen it, to
spread it uniformly upon all the apparatus of  organic life
and  thus to contribute to the regularity of their action,
are the uses commonly attributed to  the system of which
we  are treating.   It  is difficult to  assign those of the 
         NERVOUS  SYSTEM OF ORGANIC LIFE.      75

ganglions which are found in the posterior branches of the
nerves of the spinal marrow.

                Ganglions of Animals.

  Page 274.—" If the ganglions were not the centres of
certain  important  functions of which we are ignorant,
would they be so invariable in the animal organization ?"

  It is difficult to determine to what part of the nervous
system the  organs of this kind belong which are met
with  in the lowest classes of animals.  Worms  and in-
sects  have insulated  swellings, united by nervous  cords
which go off in the form of rays.  In  the mollusca, the
whole system consists of two great nerves twisted around
the oesophagus and an annular swelling which embraces
this tube.   Blumenbach, Cuvier, Gall and J. F. Meckel
admit that these parts correspond with the spinal marrow
of  the vertebral animals.  If, on  the contrary, Reil and
many others are to be believed, it  is  the great sympathe-
tic that they represent.  Walter of Landshut, assimilates
the nervous cords  of the mollusca to the nerves of the
eighth pair, by comparing to the spinal marrow those of
insects and  worms.  Weber  takes the ganglions of the
vertebral nerves as the term of comparison.  But no one
 can be exact;  there are too many differences of structure,
 distribution and functions between these imperfect ner-
 vous systems and those  of the superior animals.  What
 seems to approach nearest the truth  is the term of com-
 parison adopted by Walter for the  nerves of the mollusca,
 which in fact very much resemble the nerves of the  eighth
 pair.
   For the same reason,  we  can hardly give the name of
 ganglions to those swellings,  or rather to those irregular 
76
ADDITIONS, ice.
masses, whose nature is still but little known, which ap-
pear to take the place, in the inferior animals, of the cen-
tral organs of which these last are destitute.   It is how-
ever upon this resemblance that is founded in great part
the opinion of those who pretend that the brain and the
spinal marrow are assemblages of ganglions ;  the proof of
it is, say they, that these ganglions are insulated in the  in-
ferior animals.   We shall not again advert to this opinion,
which  is contradicted by facts  already  stated  in  the  or-
ganization, development, &c.  of the nervous system.   M.
Serres thinks, like Weber, that the insulated ganglions of
the inferior animals answer to the vertebral ganglions.
   In animals who, like  man, have the  spinal marrow
enclosed in a bony canal, the system of the  ganglions is
not by  any means developed to the same degree.  1st.
Having regard to  the whole size of the body, this system
is of so  much the more  extent  as  the animal is more
elevated in the scale of beings, consequently  as  his  or-
ganization is more perfect. The eighth pair diminishes on
the  contrary in the  same proportion.   2d.  Its develop-
ment is always in proportion to that of the spinal marrow
if we compare both  in  relation to the whole body in
general and  not to the  brain alone.   3d. The great sym-
pathetic follows also the alimentary  canal in its develop-
ment.  4th.  Finally, it is equally connected  in this  re-
 spect with the vascular system. 
ADDITIONS
                     TO THE


VASCULAR SYSTEM WITH  RED  BLOOD.
              Situation of the Arteries.

  Page 292.—" Both of them" (the trunks and branches
of the arteries) " are covered almost  every where by a
thickness of parts that protects them from external in-
jury."

  Besides, the arteries are almost every where situated in
the direction  of flexion of  the articulations.   Thus the
aorta is placed in nearly its  whole course in front of the
vertebral column.  Thus the carotids on the anterior part
of the neck, the iliacs in front of the pelvis and the sub-
clavian on the inside of the shoulder, all occupy the side
towards which the motions are the most extended.  This
becomes more evident in the extremities.  We  see,  on 
78
ADDITIONS TO THE
the inferior ones, the crural  artery  at  first  situated  in
front of the ilio-femoral articulation,  that is to say, in the
direction of the flexion of this articulation, turning within
and behind to its inferior part, and preserving the same
relation with the articulation of the knee.   The foot seems
at first to form an exception ;  but this exception is only
in appearance, what is called extension in this part being
really the direction of flexion, if  we compare it with the
hand, and is  besides the direction of the  most extended
motion.  Moreover, it is in descriptive anatomy that we
must look to see to what extent every thing, in the neigh-
bourhood of an artery, unites to protect it efficaciously from
the injuries which might alter its  structure. The arrange-
ment of which we are treating evidently  contributes to
this object, as has  been  very well seen by Soemmering.
Without it the arteries would  at every instant be exposed
to stretching, which, by elongating them too much, would
produce the  double inconvenience  of embarrassing  the
circulation of the blood in their interior, and of producing
in their texture, which is but slightly extensible, inevi-
table  ruptures.   This  situation of the arteries has also
another advantage ; it follows from it that in flexion, they
become much less  liable  to external injuries ;  which, in
various places, remedies to a  certain extent their super-
ficial position.
   In the spaces between the articulations, the arteries of
the extremities occupy in general their internal side, less
exposed than the others to the action of external powers,
especially when the limb is in adduction.

              Termination of the Arteries.

   Page  301.—<• The pilous,  epidermoid, cartilaginous
systems, &c.  destitute of arteries,  contain  only white 
         VASCULAR SYSTEM WITH RED BLOOD.      79

fluids in the division of the general capillary system that
has its seat in them."

  In  their  termination  in  different  organs, the arteries
exhibit also many points for consideration.
  1st. The course they run  before arriving at it is longer
or shorter.  We  meet in this respect with  great differ-
ences, which  themselves are not uniform, on account of
the varieties  of  origin  so  frequent  in  this  system.  In
general the  arteries  arise at a  little distance  from the
organ to  which  they arc destined.   When  a contrary
arrangement exists, it arises  from some local  cause.  It is
thus  that the spermatic arteries are, at their origin, very
far  from the testicles, because the testicles were originally
situated much higher up.
  2d. The  mode of distribution of the arteries,  their
number  and  size vary in each  organ.   There are some
which possess many arteries ; this is the case  even with
the  greatest number.   Others,  as the liver,  the kidneys,
the spleen, &c. receive  but a single trunk.  The arteries
are almost always more or less divided before penetrating
the substance of  the organs, as we  see  in the  brain, the
bones, the muscles, &c.   Sometimes they enter them  on
one side only, and occupy but a  very small space on their
surface ; sometimes almost  the  whole  circumference  of
the  organ gives  passage  to them.   Finally,  their  size
differs in the  different organs ; it is  generally in relation
with the nature of the functions which they perform.
   3d. The arteries,  when  arrived  in the textures them-
selves, give rise, by their divisions and subdivisions, to
very delicate networks.  The form  of  these networks  is
not the  same every where  ; Prochaska and Soemmering
have pointed it  out for a great number of parts.   They
are trees in the intestine, stars  in the liver, tufts  in the 
so
ADDITIONS TO THE
tongue, &c. ; so that we can by the aid of a  microscope,
at a single glance, as it were, determine  whence the ves-
sels come that are previously injected.

              Resistance of the Arteries.

   Page 306.—" This  longitudinal resistance" (of the ar-
teries) " to distension is less than the lateral resistance op-
posed to the injection ; experiments prove it, and  it arises
without doubt from  this,  that no  fibre, in  the  first case,
is found directly opposed  to the effort."

   The cellular coat is in fact almost the  only one capable
of sustaining an effort which is exerted  in the longitudi-
nal direction, whilst the peculiar coat resists with  it when
the effort is lateral.  Besides, the resistance of the arteries
is not the same in  all;  it depends  in general on the thick-
ness of their parietes;  the  cerebral arteries, which have
such delicate ones, are so  much  the  weaker than other
arteries of  the  same  size.   For  the  same  reason,  the
trunks have more resistance than the branches, these than
the smaller branches, &c ; only as  the  thickness does not
diminish in the  ratio of the capacity, it  follows that the
arteries the most distant  from the part, are, in relation
to their caliber,  the most resisting.   Another  cause, ac-
cording to Clifton-Wintringham, which makes the small
arteries resist more, is that their texture  is softer and
looser.
   But few comparative experiments have been made upon
the strength of the  arterial parietes in  the  longitudinal
direction.  The object of those of Wintringham  was to
ascertain the lateral  resistance ; it appeared to him to be
greater, in relation to the thickness even of  the parietes,
in the small arteries than in the  large ones.   The aorta 
         VASCULAR SYSTEM WITH RED BLOOD.       81

has also borne a  greater effort at its inferior extremity
than near its origin.   Gordon has endeavoured to measure
the effects of the distension ; he  has ascertained that it
requires a  greater weight  to  rupture  the external iliac,
than the  carotid.  But in  his experiments, the  rupture
took  place where  the  suspensory cord  was attached ;
there was  at the same  time a  section  of the  artery;
so  that nothing  can be  concluded from it  in  relation
to pure and  simple  distension.   If we  should wish to
repeat these  experiment, which,  however, do not appear
to lead to any very important result, we might  insulate
the artery of a limb for a certain extent without entirely
separating  it,  and afterwards employ  upon  this   dis-
articulated limb  all the necessary efforts.   We  shoulpl
avoid in this  way the inconvenience of ligatures.
   In the arterial  curvatures, the convex  side is  thicker
and stronger  than  the concave  one.   This arrangement,
no doubt  accommodated  to  the  greater  effort  of the
blood on that side, is  very evident at the arch of the
aorta.

      Nature of the Middle Coat of the Arteries.

   Page 308.—" The action  of different reagents upon
the arterial  texture, proves clearly how much it differs
from the muscular.  There are then general  phenomena
common to  all  the  solids ; but different  peculiar phe-
nomena that  are distinctive."

   Those  who consider  the peculiar  membrane  of the
arteries as of a muscular nature, and Haller, Walter and
Soemmering are of this  number, think  so, 1st, because
its fibres become soft and  greyish  in the small  arteries,
and resemble very much,  at least in appearance, those of
              11 
82                ADDITIONS TO THE
the intestine, bladder, &c. ; 2d, because the same appear-
ance  is found  in  animals ; 3d, because, notwithstanding
the dryness, resistance, elasticity and species of brittleness,
which distinguish the arterial fibre, there is not  more
difference  between this fibre  and the  muscular, than  is
found between the different  kinds of muscles ;  between
the  great  pectoral of birds  and the  muscles  of  their
claws  or stomach, for example;  4th, finally,   because
the properties which  the arteries enjoy during  life  also
approximate  their texture  to the muscular.  It might
be  added,  that it is not  very  dissimilar  in  chemical
properties  ; for  I am confident it contains a  certain
quantity of fibrin.
  These considerations nevertheless do not  seem to me
to be  sufficient to warrant us  in  ranking the  arterial
texture  among those  which  have  the  muscular fibre
essentially  for  their  base.   I  think  rather,  considering
the elasticity which forms the principal character of it,
that this texture belongs, as some anatomists have already
thought, to the yellow or elastic fibrous system which
will be examined hereafter.

   Cellular Membrane and Sheath of the Arteries.

  Page  318.—" The  arteries have around them  two
kinds  of cellular  texture ; one, which  is  very external,
loose,  fatty, full  of serum, with distinct layers, unites
them to the  neighbouring parts ; the  other, firm,  com-
pact, not  fatty, filamentous and not lamellated, forms
the first  of their coats."

  This cellular coat, (cellulosa propria  of Haller) re-
jected  by  Monro, Walter,  Scarpa  and Mascagni,  and
which Soemmering united to  the peculiar membrane,  is 
         VASCULAR SYSTEM WITH RED BLOOD.      83

not less distinct from  the other coats  which  it  covers,
than frotri the cellular texture which surrounds it.
  It  is  a  fibro-cellular  membrane,  delicate,  tolerably
dense  however, and  really  forming  a constituent  part
of the arterial tube.  In the great arteries it  is  divided
into two laminae;  one  external, which  approximates
more to  cellular  texture ; the other  internal, yellowish
and  tough,  which resembles  the layers  of the middle
coat.   Its appearance  upon  the  arteries of  the middle
size is that  of the  aponeuroses, or still more of the neu-
rilema.  Its texture is composed of fibres  interlaced and
Oblique,  more separated  without  than within ;  these
fibres  are especially apparent in  the distension of the
artery, either lengthwise, or across, because they stretch
and  separate before  breaking.    Mascagni  has  given  a
good  plate of them.   The small  arteries  have this coat
thicker than the  large ones, in proportion to their size ;
it  is  on this account that  they  bear ligatures  better,
which, as is knowm, only act upon the cellular coat.
  Into this membrane are inserted many soft and exten-
sible  filaments, which  come from a  species of sheath
which the artery receives from  the surrounding cellular
texture.  It is the  only relation  which there is between
it  and this  cellular texture.  By means of this arrange-
ment, the artery slides easily in  the interior of its  cellu-
lar canal ; the retraction of divided arteries is very much
favoured by it.
  The cellular sheath of the arteries, the  external coat
of Soemmering, described by Haller  under the  name of
tunica cellulosa  adscititia, is in fact nothing  but this
lamellated cellular texture which joins and embraces them
so as to form a real canal around  them.  Hebenstreit has
treated of it in a dissertation which forms a part of the
Collection  of Dissertations of  Haller.  This  sheath  is 
84
ADDITIONS TO THE
attached on  one side  to the external membrane  by the
elongations of which we have just spoken, and  is  con-
tinued on the  other  with  the  cellular system.   It is
wanting in some arteries which  have serous coverings.
Others are destitute of it, from the want of cellular tex-
ture in the parts where they are found.  Its arrangement
varies like that of this texture ;  in  general  compact on
the  extremities, it  is  very loose  in  some parts, around
the  spermatic  arteries for  example.  These  differences
deserve an examination, because they may explain various
morbid phenomena.   Thus  arterial ruptures are followed
in the brain by  a general effusion which disorganizes its
substance, whilst in the  extremities the cellular sheath
prevents this accident by circumscribing the  progress of
the effusion  ; thus, in  this last case, the blood infiltrates
to  a greater or less  extent according to  the resistance
which the sheath opposes to it, &c.

                Nerves of  the Arteries.

   Page 322.—" There is merely juxta-position" (between
the cerebral nerves and the arteries) " as we see  it in the
extremities, in the intercostal spaces, &c."

   The nerves of the arteries are so much the more abun-
dant in proportion  as  these vessels are of  a  less caliber;
they are more evident upon the  branches than the trunks.
Those of the arteries of the extremities come in part from
the cerebral nerves.   Lucae says  that he has traced them
into the arteries.   He  has made two classes of them in
relation  to  their course;  1st, some  stop  in the  cellular
 coat and are lost there, after having run some time in the
 cellular  texture  which surrounds it ;  2d,  others  pass
 through this coat and go to the peculiar membrane, upon 
VASCULAR SYSTEM WITH RED BLOOD.
85
which they are spread into a very delicate network.   The
first are short and  flattened;  the second,  which are ex-
tremely delicate, have a little more consistence, their form
is rounder and they run a shorter course.   No one reaches
the internal membrane ; Oudemann says  however that he
has traced them to the nervous membrane of Haller.  Some
arteries appear to be destitute of nerves.  The pulmonary
tree receives fewer of them than the aortic. According to
Lucae, the nerves of the  arteries are less apparent in old
age, particularly the filaments destined for the middle coat.

         Irritability of the Arterial Texture.

   Page 332.—" The contraction produced by the defect
of  extension, is that which  characterizes  the contractili-
ty of texture.   Irritability or sensible organic contrac-
tility, on the contrary,  uniformly supposes the applica-
tion of a stimulus."

   Notwithstanding all these considerations, there are phy-
siologists, who allow to the arterial texture the faculty of
contracting under the influence of an appropriate stimulus.
The reasons which they allege in  favour of this opinion,
are the  following.   1st.  If the arteries,  say they, do not
always contract in experiments, they resemble in this res-
pect some textures of whose irritability there is  no doubt.
The intestines, the bladder and the stomach sometimes
give no sign of irritability.  2d.  The action of the acids,
which Bichat considers as a mere horny hardening,  is dif-
ferent during life and after death ;  in the first case, there
is  a real contraction ; in  the second, it is rather  a kind of
erosion, as Verschuir has seen.  3d. The same author has
succeeded  in  producing  a contraction of  the artery, by
merely irritating  it with a scalpel.   4th. In other experi- 
86
ADDITIONS TO THE
ments, the simple contact of the air has produced a sudden
and  very evident contraction, sufficient to efface almost
entirely  the cavity of the artery.  5th. This  contraction,
in all these cases, extended beyond the point  touched;  it
ceased when the stimulus was removed.   6th. The elec-
tric  spark lias also produced contractions according  to
Bikker and  Van-den-Bos.  7th.  It  is even said  that this
effect has been  obtained by applying stimuli to the nerves
of the arteries.   Galvanism has been successfully employ-
ed in this way by  Giulio and Rossi.  Home employed
alkalies;  their  contact with the great  sympathetic nerve
produced violent  pulsations in the carotid artery.   He
was  led  to this experiment by the  local changes which
the circulation  appeared to experience from severe pains
from an  ulcer.  8th.   Thomson  has  seen the   arterial
parietes  contracted by the action of  ammoniac, so that its
cavity seemed to have entirely disappeared.  The muriate
of soda, on the  contrary, almost uniformly dilates them.
   Many of these experiments require, no doubt, to be
repeated; but we cannot deny, that the contraction of the
arteries may be very different during life from what it
is after death;  for, 1st,  an artery, opened between two
ligatures, does  not continue to empty itself some instants
after death, except  from an excess of distension,  its  elas-
ticity does not  make it contract.  2d. Arteries, emptv  at
the moment of death, and being still contracted in virtue  of
this contraction, return to their ordinary dimensions when
all vital  influence has entirely ceased :  their elasticity,
which resumes  its ascendancy, then supports their parietes
separate ; this is  what is seen especially in death, from
hemorrhage ;  3d,  so in  the  experiments cited  above,
the  contraction  ceased  after  death,  and that  which
was  obtained  by putting  the elasticity  in  action  by
the distension of the parietes was much less marked.  No 
        VASCULAR SYSTEM  WITH RED BLOOD.       87

doubt that the force which thus makes the  arteries  con-
tract during life does not differ from that which presides
over the  contraction of the heart,  the intestines,  &c. ;
perhaps it is wrong to  give  it the name of  irritability ;
but that of contractility of texture is no more  suitable
to it.   Kramp has proposed to make a particular force of
it which he calls the vital force of the arteries.  Parry
refers all  its  effects to tone or insensible organic  contrac-
tility.  Whatever be itsnature, its intensity increases as the
arteries become  smaller,  which  Soemmering attributes
to the greater quantity of nerves which the small  ones
receive; the elasticity diminishes in the same proportion.

       Action of the Arteries in  the Circulation.

  Page 345.—" It is not the contraction of the arteries
that drives the blood to their extremities.-----Each jet of
the arterial throw should correspond to each relaxation of
the ventricle ; the contrary of this is the case as I have
just said."

   If the arteries do not contract upon  the blood,  the flow
of this fluid  would  not be  continuous but  intermittent;
whilst it  is, as it were, remittent.  The jet of an  open
artery is  increased  at  each  contraction  of  the ventricle,
because this  contraction increases the velocity of the cir-
culation.   It is diminished in the  relaxation because  there
is then only  the  arterial  action  which  makes the blood
flow.  The jet should cease entirely at each relaxation of
the ventricle, if  it was only owing to  the  contraction of
this last.   There are then two causes of the  motion of the
blood.  1st. The arteries, always  full, constantly tend, by
their elasticity and contractility to react upon this  fluid.
2d.  The contraction of the heart is added  to this by in- 
88
ADDITIONS TO THE
tervals, and gives to the motion a  new activity.  This
last cause is much the most important, especially in  the
great arteries, but the first is nevertheless real.

        Development of the Vascular System.

  Page 364.—" The arteries are made to  develop them-
selves, and the heart does not hollow them out, as Haller
has said, in the interior of our organs by the force of its
impulse.  This mechanical manner  of considering their
formation is evidently contrary to the known laws of the
animal economy."

  The opinion  of  Haller is  so much the less admissible,
as it appears that there are vessels before the heart exists.
The development of these vessels, and in general of the
whole vascular system, is a point still obscure, but never-
theless curious.   Malpighi, Haller,  Wolff, and especially
in recent times Pander, have traced  it in the chick.   The
first vessels appear in the membrane of the yolk, which
represents the umbilical vesicle of man  and the  superior
animals.   The vein of this part appears before any of the
rest of the vascular system.   Its ramifications commence
by small insulated cavities, species of vesicles, which are
afterwards united  by grooves.   They are at first mere
hollowed  passages in the membrane of the yolk,  filled
with a colourless  fluid ; the blood  afterwards shows its
colour in them, the parietes become more distinct and their
consistence greater.  The small branches,  branches and
trunk of the vein are developed in the same manner.   The
vena porta succeeds to that of  the  vesicle, of which it
appears to be but a continuation.   Soon after this vein is
enlarged at  its  superior extremity to give origin to  the
heart.   This is then semicircular, and formed entirely by 
        VASCULAR SYSTEM WITH RED BLOOD.       89

the left ventricle.   The origin of the aorta is afterwards
joined to  it and then the  auricle; both at first quite dis-
tinct from the ventricle, gradually  approximate it.   The
space which thus  exists for some time between this last
and the auricle, is the auricular canal.  From the aorta
arise  successively all the other arteries, beginning with
that of the yolk  or vesicle, which  the  vessels of the
allantoid membrane soon follow ; the development of the
arteries is followed by  that of  the corresponding veins.
On the other hand, the liver is developed and the vena
porta, united to the umbilicus, is almost exclusively dis-
tributed there ; the portion of this vein which is extended
beyond forms the ductus venosus.  The  cavities of the
heart are  completed ; a partition divides the auricle into
two parts, which still communicate by a large opening ;
there arises from the superior  part of the left ventricle a
small tubercle, which by extending  towards the apex of the
heart, gives  origin to the  right ventricle.   At this period,
the base of the heart which the left side alone forms, estab-
lishes a communication between the two ventricles, which
makes the aorta  seem to  arise from  both of  them ; the
pulmonary artery is yet only indicated by a bifurcation
which the aorta exhibits a little above its origin ; the two
branches  which  result from this  bifurcation unite  again
after  a short course.   In  the ulterior  development of the
heart, the place of their separation  is found  more and
more approximating this origin ; the  two divisions finally
detach themselves entirely,  and the pulmonary  artery
becomes a trunk  insulated at its origin, and forming as it
were  a second  branch to the aorta.   It is itself divided
for the lungs of each side,  and takes beyond the name of
ductus arteriosus.
   By admitting that these  phenomena, observed in the
oviparous animals, take place also  in man, as  some facts
              12 
90
ADDITIONS TO THE
seem to prove, we see, 1st,  that in the  beginning the
circulating organs are much less  numerous than they are
to be afterwards.  The heart has but  one ventricle and
one auricle; the vena porta is the only venous trunk, the
aorta the only artery, &c.   The motion of the blood must
then be very simple  at this  period ;  this is  also what is
observed in the chick.  The blood, in this last, runs a very
simple course at the commencement ; it  is a single circle,
formed by the vein of the yolk, the vena porta, which is a
continuation of  it, the heart,  the  aorta and the artery  of
the yolk.   There  must be added  to it afterwards the um-
bilical  vessels, whose development follows  nearly that
of the vessels of the vesicle ; this gives a little more extent
to the  circulation  without  rendering  it much more com-
plicated.   2d.  In a second period, on  the contrary, the
circulatory organs are more numerous  than  after birth.
Thus the ductus  arteriosus, the ductus  venosus, the um-
bilical arteries and vein and the foramen ovale are after-
wards to disappear.   There however remain traces of the
simplicity of the first period ;  the auricles, though two  in
number, communicate together;  the course of the blood
is much more complex, but the two circulations are still
in part confounded.   It is not  until this  second period
that the circulation begins  to be well understood in man.
  MORBID  ANATOMY OF THE VASCULAR  SYSTEM  WITH
                     RED BLOOD.

        I. Alterations in the External Forms.

  The  arteries  often  increase  in  size,  either in their
whole  extent, or in a single point, or even on one side
only of their circumference.   The increase of the arteries 
        VASCULAR SYSTEM WITH RED BLOOD.        91

in their whole length is a real hypertrophy, which takes
place when the organs  themselves are the seat of  an
excess of nutrition, when they experience a very acute
and long continued irritation, and under various circum-
stances  pointed out above.  After the obliteration of an
artery, the collateral branches do not increase in breadth
only, but in length also ; thus they describe curves which
did not  before  exist.  The partial dilatation constitutes
one of the varieties of aneurism, the true aneurism of the
ancients.  This affection is in fact  in the beginning only
a simple, circumscribed and sac-like dilatation of the three
arterial coats, as is proved by  many observations ;  the
artery is rarely dilated uniformly and in  its whole  cir-
cumference ; when this  takes  place the disease exhibits
differences sufficiently striking to  warrant us in distin-
guishing  it,  as  Scarpa has done,  from aneurism; these
two kinds of dilatation are sometimes united.
   The contraction of the  arteries  is  less  common than
their dilatation.   1st.  It is observed whenever the blood
ceases to pass through them, or does it in less quantity, as
happens in gangrene, especially in that variety known
under the name of dry gangrene, in some cases of atro-
phy,  paralysis, &c.  2d. Circumscribed  contractions, the
cause of which it is very difficult to determine, have been
met   with, particularly in  the  great arteries,  such as the
aorta and the pulmonary artery.   In the greatest number
of cases the texture of the artery is however sound ; some-
times it  has  been found thickened.  There is often  con-
nected with this  alteration some organic  disease of the
heart, or even  the rupture of  this organ.  3d. Various
tumours,  situated in  the course of the arteries may also,
by the pressure they exert, diminish  their caliber more
or less.  Old aneurismal tumours produce this effect upon
the arteries in  which they are situated,  and  upon the 
92               ADDITIONS TO THE
branches they are near and which they compress.  Under
almost all these circumstances,  the contraction of the ar-
teries may extend even to their obliteration.
  The manner of distribution of the arteries  undergoes
important changes when  a principal  trunk is obliterated
in a part; there is then formed one or more anastomosing
passages which supply  the  place  of the trunk  in  the
whole course of its obliteration,  and which  carry  the
blood from the last branch furnished above the obliterated
trunk, to the first furnished below it.  This is what is seen
in ligature  of an  artery, after  wounds of these vessels,
aneurisms, &c.

         II. Alterations in  the  Organization.

  The internal membrane is much  more susceptible than
the others to inflammation.   Sometimes this state is first
developed in this membrane, sometimes it is transmitted
to it from other organs ;  it is thus that in acute inflam-
mation of the thorax or abdomen, the internal membrane
of the aorta has sometimes been at the same time  found
greatly inflamed ;  in the  affected  parts  themselves, the
arteries commonly partake of the  inflammation  of  the
other textures.  The redness  which characterizes this
arterial phlegmasia  is usually accompanied by  a thicken-
ing of the  membrane and an effusion of an albuminous
nature, sometimes very copious ; the vessels of the pecu-
liar membrane are also frequently more or less engorged.
  Inflammation of the arteries is followed by their oblitera-
tion, when  the two sides of the inflamed  internal  mem-
brane unite together.  This adhesion is owing,  like most
of the phenomena of this kind, to  the circumstance that
the effused  fluid passes to the solid state and forms a sort
of false membrane  which afterwards becomes organized. 
         VASCULAR SYSTEM WITH RED BLOOD.       93

It is in this way that we can understand how, notwith-
standing  the destruction of the arteries in ulcers often-
times very extensive, no hemorrhage takes place ; the
preceding inflammation  has first  obliterated the vessels.
Pus has  never been found in the arteries; perhaps it is
carried off by the blood, as fast as it  is formed.  Ought
we to refer to a state of  induration or of chronic inflam-
mation many of the organic diseases of the arteries, which
are accompanied by a greater thickness and consistence of
their texture?  This question cannot be resolved.   What
is certain is, that inflammation, connected either inciden-
tally, or as effect or cause, is often united to similar altera-
tions.  Gangrene never  succeeds to the inflammation of
the internal membrane alone;  but the arteries are  often
comprehended in eschars ; it happens  then, that the blood
is coagulated beyond the dead portion, so that there is no
hemorrhage when  the eschar separates, unless the  vessel
be very  large.
   The cellular texture exterior to the arteries  is  subject
to the same alterations as the rest of the cellular system ;
inflammation may engorge, thicken and ulcerate it, suppu-
ration may destroy it, &c.  The cellular coat, properly so
called, is but very  rarely inflamed.  When it happens and
the  inflammation  is  long continued, there  sometimes
results  from  it  that  sort of brittleness which has been
treated of  in the article on the cellular system ; a brittle-
ness which has perhaps, however, been much exaggerated.
   That  state of the arteries of which Bichat has  spoken
and which resembles their inflammation, because  it con-
sists in a more or less extensive redness of their internal
membrane, has been met with in cases in which it could
be attributed neither to  maceration, exposure to the  air,
the presence  of a  coagulum nor  to  the time that  had
elapsed  since death.  (See Hodgson on the diseases of the 
94
ADDITIONS TO THE
arteries.)  We know not then  if it be not, under some
circumstances, a real morbid  alteration.  According to
Franck, this redness was constant and occupied the whole
extent of the arterial system in a species which he had
occasion to observe.
  The solutions of continuity of the arteries differ, accord-
ing as they penetrate the  cavity  of the vessel,  or affect
only a part of its membranes.
  The first  case, which is the most common,  has been
very well observed by Dr. Jones upon dogs.  I have also
made some  experiments upon this subject.  The follow-
ing is what takes place when an artery of a living animal
is opened.
  1st. If it  be by  a simple puncture, with the point of a
needle for example, a small quantity  of blood flows,  a
coagulum is formed in the cellular sheath and  stops  the
hemorrhage.  This coagulum afterwards  disappears, the
edges of the opening inflame, and adhesion takes  place.
The cicatrix is confounded in time with  the arterial tex-
ture,  and no traces  are left of the  small  wound.  The
cavity of the artery is preserved.
  2d. When the wound is of some extent, the issue is
different according  to the  state of the cellular sheath and
the direction and size of the  opening.   If the sheath has
been destroyed, the hemorrhage  continues in all cases ;
and, though suspended for  a time by  syncope, it only
ceases with  the life of the animal.  When, on  the con-
trary, the sheath remains  uninjured, 1st, if the wound be
longitudinal, to the jet of blood which escapes,  succeeds
the formation of a clot which shuts the opening ; then this
cicatrizes, as  in the  case of simple puncture ;  only  the
cicatrix remains apparent ; it is  linear,  continuous with
the texture of the  artery,  and is seen very well  by open-
ing this last and examining its  parietes against  the light; 
        VASCULAR SYSTEM WITH RED BLOOD.      95

2d, if the wound be transverse, but occupying only a quar-
ter of the circumference  of the  artery, the hemorrhage,
though more abundant than in the preceding case, because
the retraction of the arterial  fibres gives a circular form
to the opening, may still stop of itself, and its suspension
be followed  by the formation of a  cicatrix, of which I
have preserved  examples ; 3d,  if  the wound embraces
half the circumference of the artery, the opening takes an
elliptical form, and death necessarily ensues ; 4th, finally,
if three  quarters  of the circumference  of  the  artery
have been divided, the  separation is  very considerable;
the  opposite  ends of the artery,  extremely  elongated,
represent, if we may so say,  the extremities of two pens
united at their  points ;  the  kind of tongue that  unites
them is finally broken, and the  cure, when it is effected,
is made by the obliteration of the vessel.
   3d. In  complete  transverse  sections, death does not
take place unless there is at the same  time denudation of
the artery.   When the sheath is left, the wound is almost
always  cured in animals  by an obliteration  of the artery.
The two  ends retract into the  interior of their cellular
canal, which thus extends beyond their  extremity.   The
hemorrhage  brings on weakness and syncope; the blood
is effused and finally forms a coagulum which, filling the
sheath, surrounds the artery  and  shuts  its  extremity.
When the force of the heart returns, the coagulum  resists
and the hemorrhage does not again come on.   The blood
coagulates in  the artery  as far  as  the  first collateral
branches, the parietes of the  vessel contract, a cicatrix is
formed at each  end and obliteration takes place.   This
obliteration  is,  according  to  Jones, the result of a lym-
phatic  effusion which is poured out in the artery near its
extremity,  between  the external  and  internal  coagula.
When this takes place, the coagula are absorbed  and dis-
appear. 
96
ADDITIONS TO THE
   The same things do not always take place in man.   In
 punctures, for example, it is extremely rare that the cure
 is solid,  unless the artery is at the same  time obliterated.
 The hemorrhage in this case left to itself, continues with-
 out interruption; the blood, if it does not flow  out, is
 effused into the  cellular texture, and produces a diffused
 or primary false  aneurism.   Suppose  that by compres-
 sion or rest,  a coagulum should be formed, and a cicatrix
 even established, the cure may be only apparent.  Though
 this  state may continue for years, the blood will  finally
 remove or break these feeble barriers and a tumour will
 appear;  this will be a  circumscribed or  consecutive
false aneurism.  Such is at least the result of facts  ob-
 served up to the  present time.  It  is true that  we are
 almost always ignorant of the direction and  extent of the
 wound ;  and, as has  been seen, the termination is very
 different in this  respect.   It is thus extremely probable
 that a puncture  made lengthwise would  heal  as well in
 man as it does in animals.
  Spontaneons cure is likewise very  rare, in  man,  of
 wounds  which  comprehend the whole  circumference of
 the artery ;  and, unless the caliber  be very small, these
 wounds,  left to themselves, are uniformly fatal.   It is
 necessary however to except from them, 1st, certain cases
 in which, notwithstanding  the  considerable size  of  the
 vessels opened,  a coagulum formed  during a  syncope
 has been  sufficiently powerful, or rather the circulation has
 been  sufficiently feeble, so that the hemorrhage has not
 reappeared and the adhesive inflammation has had time to
 take place ;  examples of this kind are cited by Boerhaave,
 Garengeot and others.  2d.  Wounds from fire-arms and
 those which  result from the action of fire  and caustics;
 here it is the eschars which prevent the hemorrhage, and
 when they fall off the vessels are often obliterated.  3d. 
         VASCULAR SYSTEM WITH RED BLOOD       97

Lacerated wounds; I have collected a number of observa-
tions  respecting  them  made by authors ; the most re-
markable  is  the  case  of Samuel  Wood, related  in the
Philosophical Transactions, and  since in various works.
In some of these  observations, death has been the  con-
sequence of a copious hemorrhage ; but in the greatest
number, as also in  the  experiments which I have  made
upon animals, a cure has taken place.   Besides the retrac-
tion and  contraction noticed by Bichat, twr*  additional
causes are opposed in  this case to  the flow of blood, and
favour the obliteration of the artery.  In fact, at the instant
even  of the accident, this yields  and is elongated  before
breaking ; but the internal  membranes,  less  extensible,
are torn  at  first  unequally and in different places, and
then  are  completely separated, whilst the cellular  coat
continues to  stretch, approximating more and more the
axis of the vessel, like a tube of melted glass  drawn at
both ends.   When the separation is completed, the artery
exhibits then at  its extremity a conical  elongation, ter-
minated  by a narrow opening, and in  its interior  irregu-
lar shreds which obstruct its  cavity.   This last  circum-
stance appears to be the most important of the three, for,
1st, the retraction is often wanting, the end of  the artery
is pendent, and yet there  is no hemorrhage; 2d,  by cut-
tins in an animal the summit of the  kind of cone which
the artery forms,  the flow of  blood does  not  return,
unless the section be made  above the internal lacerations.
   Solutions  of continuity, which affect but one part of
the arterial membrane, act  upon the  internal or  external
coats.  Hunter and Home have seen,  that if the internal
membrane be laid bare in  dogs, by cutting the external
and middle  ones, there  results  from it  an  albuminous
exudation,  by which  the thickness  of the  artery is in-
 creased.  They  have even removed these membranes to
              13
                                                \ 
98
ADDITIONS TO THE
a certain extent, without the internal one being distended
by the blood.   This must however  take  place  in  man
m what is  called mixed or internal  mixed aneurism,
aneurysma herniam  arterias  sistens, in  which  it is
supposed the  sac is formed  by the  internal membrane
dilated.  Many authors reject this  kind  of  aneurism,
but examples of it have been given.
  It has been thought, that the distension of the arteries
during life, v  violent motions, might produce the rupture
of the nternal membranes and thus dispose to  aneurism.
Bui. the arteries are everywhere  so  arranged that  it is
impossible that their distension  can  o™°sion even a par-
tial rupture, of which it is easy to u~   ^nvinced on the
dead body ; this would  not hap^-ii  unless tb~ir  parietes
were  the seat of seme  organic  disease.   This  internal
rupture is observed, on  the contrary, under the following
circumstances.   1st. By pressing with a pincers an artery
of ar. animal, we effect  the division of the  internal and
middle  membranes, the  external  one remaining whole  ;
the small wound, which results  from it, cicatrizes, and
the artei-y loses nothing of its strength in this  place ;  its
parietes are even  rather thicker; when there is a  great
number of lacerations,  the obliteration of  the  artery is
sometimes the  consequence.   2d.  What in the preceding
case, happens  to a moderate extent, takes place circularly
from  a ligature, as  has  been  elsewhere said.   There is
also this difference, that  the edges of the \vou;:d  being in
contact are agglutinated by a mechanism  analogous to
that of the  reunion  of wounds by the first intention.  The
artery is then obliterated ;  th^ blood is coagulated above
and below  the cieFvix,  as  far  as  the first  collateral
branches ;  the obliteration  goes all this extent.   If  these
br-riches are  very  near, the  coagulum being very weak,
the cicatrix is not maintained, and  a hemorrhage may take 
         VASCULAR SYSTEM WITH RED BLOOD.      99

place when the ligature comes off, and even before, when
the membranes begin to be  broken.   Jones says that it
is not necessary for a ligature to remain applied upon an
artery in order that obliteration  should  take place ; by
placing many ligatures and removing  them successively,
he has seen- this effect produced.  Travers assures us that
obliteration  is  certain when  the ligature  has remained
applied for an hour ; though  the blood often resumes its
course at the end of that time, the artery is not the less
obliterated, according to  the experiments of this  author.
I have uniformly seen in  my experiments  the  artery re-
main  permeable,  when  the  ligature  has been removed
even at the end of twenty-four hours ; it was  not closed
definitively until  the adhesion was established at the mo-
ment the  ligature came  off,  which commonly happened
at the end of eight and forty  hours.   3d. If an aneurism
be of any standing, the internal membranes yield to  the
distension, as we have seen ;  they are torn by the  mere
effort of the  blood or by any external violence.   The
tumour, which is then formed by the cellular coat alone,
makes more rapid progress ;  the  blood coagulates  in its
interior  and  forms fibrous layers, the density of which
increases as they are removed from the axis of the vessel;
the sac, freed from these eoagula, exhibits  on its internal
surface an irregular line which indicates the  point where
the membranes  cease ; these are sometimes floating, and
exhibit a sort of incomplete partition  which separates the
cavity of the sac from  that  of the  artery ;  this  is the
true aneurism, arrived to  that degree which  some  have
called external mixed.   In time, the cellular  coat itself
is affected, it is destroyed, and the sac is formed only of
the cellular texture and the other surrounding parts.   4th.
In  another  species" of aneurism, which, at an advanced
period, does not  differ sensibly from  the preceding, and 
100
ADDITIONS TO THE
which  has been  designated  under  the  same name, but
which others call spontaneous aneurism, the destruction
of the membranes precedes the formation of  the tumour.
This destruction is here owing to the  ulceration or  rup-
ture which the internal membrane experiences in organic
diseases ; the blood is then confined below this membrane
and distends the  cellular coat.   This variety of aneurism
is perhaps the most common ; but it is not correct to say
that all  begin  in  this way.  Moreover, the ulceration of
the internal membrane is not always followed by aneu-
rism ;   M.  Cruveilhier has  found  this  membrane  des-
troyed as well as the fibrous, and yet there was no dila-
tation of the cellular coat.
  Foreign  bodies,  in  contact with  the  arterial texture,
inflame  and often ulcerate it so  as to open the cavity of
the vessel.   If these bodies act by approximating to  each
other the parietes of the artery, they produce an adhesion
of these parietes.  When  they  make a circular constric-
tion, like  a  ligature, they produce  mortification  in  the
narrow  portion which they embrace, and are afterwards
removed with it; this is  what takes  place with a ligature
at the end of from eight to twenty days.
  We know the frequency of arterial ossifications ;  they
exhibit  many forms.   There  are  circular  ones  which
invade  arteries  almost in  their whole length ; they  ex-
tend to  the peculiar membrane, and are sometimes attend-
ed with  a contraction and obstruction of the  vessel ; that
species  of  gangrene which is called  senile is oftentimes
the consequence of it.  In other cases,  the  incrustation
is much more limited ; there  is  only on the interior of
the artery a  great  number of small  white marks, super-
ficial  and  but slightly prominent.   Between these two
extremes are found yellowish plates, semi-transparent and
irregular, which appear at first to be situated in the space 
        VASCULAR SYSTEM WITH RED BLOOD.     101

between the two membranes, but which the blood  after-
wards touches immediately, because  the  internal one is
destroyed on their surface.
  The cartilaginous transformation has also been observed
in the arterial texture.   It has  its seat in the  internal
membrane,  and is characterized  by plates of  a  white
colour,  prominent, fibrous and  very dense.  The  carti-
laginous state  almost uniformly precedes the  ossifica-
tions of the arteries which take place in adult age, whilst
those of old people are owing simply to irregular deposi-
tions of calcareous matter.
   The arteries are changed into a fibrous or ligamentary
texture, whenever their  cavity is obliterated naturally or
preternaturally.   This  texture  in  time  becomes  more
delicate, and disappears  itself or is  confounded with the
cellular texture.
   There are some morbid alterations peculiar to  the arte-
rial  texture; they have hardly any thing in  common
with those  which  affect the  other textures.  1st.  Some-
times in aneurisms the internal membrane is found  thick-
ened,  softened, and  as  it were fungous.  2d.  Growths
similar in form to those  which are the product of syphilis
have been  met with in  the  aortic valves; Hodgson has
even seen them in the femoral artery.  3d. The deposi-
tion of a pultaceous  substance on or under the internal
membrane is a much more  frequent alteration.   It has
been compared to  steatoma;  but there is a greater anal-
ogy between it and the tubercular affection.   Sometimes
this substance, irregularly disseminated, forms on the inte-
rior of the  artery small yellowish  granulations, covered
with an extremely delicate pellicle; sometimes, accumu-
lated between the  internal and  the fibrous coat, it forms
round masses, which obstruct more or less the  cavity of
the  vessel, or even real centres, filled  with  a purulent, 
102
ADDITIONS TO THE
opake and yellowish fluid.   The tumour, in the last case,
terminates  sometimes by opening  into the  artery.  At
others, the substance hardens and assumes all the charac-
ters  of the osseous productions; it then  contains  much
phosphate  of lime.  This  affection  is often connected
with  the  osseous  transformation.   Both are common in
aneurisms especially the first.
  The arteries partake of the affections of the organs of
which  they make a part.  Their destruction, in cancer-
ous,  tubercular  and other  affections,  produces various
hemorrhages; sometimes,  however,  their  obliteration
prevents the flow of blood.

        III.  Alterations in the Development.

  Without speaking of the numberless varieties of origin,
distribution,  &c.  observed  in  the  arteries,  and which,
being all different from the natural  arrangement,  exert
however only  a  very  limited influence  upon  the  cir-
culation, it will  be sufficient to point out some  of  those
the importance of which is greater in this respect.   The
heart has  been seen wanting with  all the superior parts,
and consequently  also  their vessels.   In  the heart itself,
it sometimes happens that there is but one auricle and one
ventricle ;  the  pulmonary  artery  arises   then  from the
aorta.   Or it is the  partition between the ventricles that
is perforated; or it  is  the  foraman  ovale which is pre-
served, or  the ductus arteriosus that  remains permeable.
In one  instance  the aorta  terminated immediately after
its ascending portion, and the pulmonary artery continued
it below.   In another,  the  trunk  of the  first was bifur-
cated so as to embrace  the trachea  and oesophagus.
  Besides  the  capillaries  which  are  developed  under
many  circumstances, arteries  of a  certain size  are  some- 
        VASCULAR SYSTEM WITH RED BLOOD.     103

times preternaturally produced,  Charles Parry says that
he has  found,  in a sheep  in whom he had  divided  the
carotid  artery,  new arteries  which went parallel from
one  of the two ends to  the other, the whole extent  of
the cicatrix, and thus reestablished the  circulation. 
 
ADDITIONS
TO THX
VASCULAR SYSTEM WITH BLACK  BLOOD.
                  Venous  Valves.

  Page 406.—" We find in the works of Haller very
minute descriptions of the  general arrangement, form
and position of the vascular folds of which we are treat-
ing."

  The following should be added to what Bichat has
said.
  1st. These valves are more* numerous in  the superficial
than in the deep-seated veins, in those of the extremities,
than in those  in the interior of the trunk; the superior
extremities have fewer of them than the inferior.  In gen-
eral they are not found in the branches of communication
             14 
106
ADDITIONS TO THE
 of the veins, such as the median of the arm.  The veins
 of the heart are entirely destitute of them ; it is usually  the
 same with those of the uterus.   The  spermatic veins of
 woman have no valves, those of  man have.  It is  on  the
 inferior part of the extremities that there are the most of
 them ; the veins of the exterior of the head contain but a
 small number; there are usually some at the opening  of
 the branches in  the trunks.
   2d.  The loose edge of these valves is thicker than the
 rest, and forms, like the adherent one,  a sort of cushion.
   3d.  Above the  valves, the vein exhibits a  dilatation
 which produces a  depression on the interior and  a pro-
jection on the exterior of the vessel.   This arrangement,
 in some cases, gives  rise to  knots, which  are  only seen
 at the  places where the valves are.
   4th. Besides the two membranous  layers which, it is
 said, form the valves, though they can in no way be sepa-
 rated, fibres appear to enter into the composition of these
 folds ;  at least, by examining  them  upon  one of  their
 faces, white, interlaced filaments can often be distinguished.
 Sometimes also  the valves are perforated and formed  by
 an areolar texture.
   5th. Perrault  has established  many species of  valves
 according to the form which they  affect.  The  only real
 difference in this respect  is,  that in the great veins they
 are very broad, and the  curve wrhich they describe small,
 whilst  in the small  ones  their want of  breadth renders
this curve more  evident.  The valves are also broader at
the angles of union of the  branches  with  the trunks.
This is independent of  the state of contraction or dilata-
tion of the veins, which has an influence upon the size  of
the valves, as has been seen above. 
VASCULAR SYSTEM WITH BLACK BLOOD.     107
              Contractility of the Veins.

  Page 415.—"The question," (viz. whether the veins
are 'irritable,) " is  not, then, fully settled, though  I in-
cline much more'to the belief that there is no venous irri-
tability."

  Whatever may be  the name under which we would
wish to designate the contractile  force of the venous tex-
ture, we  cannot refuse  to admit that this texture pos-
sesses, during life, a property very different from all those
which are  found in it after death, and  consequently one
essentially  vital.  It is in virtue of this property  that a
vein opened between two ligatures drives out from a dis-
tance the  blood  which it contains, whilst in the same ex-
periment  made upon the dead body, the blood only oozes,
the effect alone of the elastic spring of the parietes.  The
contractility of  texture, in the sense  which Bichat gives
to this word, cannot  be the cause of this  phenomenon,
since it exists after  death as well  as  during life.  If we
compress in a living animal the principal artery of a limb,
taking care  to  keep the limb in  a  horizontal  position,
we shall  see the sub-cutaneous veins gradually  contract,
though the circulation may be suspended in the artery, and
empty themselves  of all the blood which they contained
at the moment of the experiment.  In the dead body, the
veins  do not contract thus upon the blood they contain;
their size depends  always upon the quantity of this fluid
which remains  in  them at the  instant of death.  More-
over it is with this contraction as with that of the arterial
texture, it  cannot  be referred  to  any of the forces which
preside over the other kinds  of contraction.   The galvanic 
10S
ADDITIONS TO THE
stimulus appears to be capable of producing it,  though
this has been  denied.
  Verschuir  calls this  contractile faculty of the  venous
texture irritability ; Whytt gives it the name of vibra-
tory  motion of the veins ; Kramp  designates it simply
under that of vital force of the veins, and others refer it
to tone.  I shall not decide which of these denominations
is preferable; I would merely observe, that there is in the
venous motions  during  life something besides the effect
of the elasticity of inanimate matter.

                Venous Circulation.

  Page 420.—" The blood is evidently beyond the influ-
ence of the heart when  it arrives in the veins."

  This opinion is diametrically opposed to that of Harvey
and  the  mechanicians  of his time, which  some modern
physiologists  have adopted.  They  consider the heart as
the sole  agent of  circulation, venous as well as arterial;
Harvey compared it to a suction and forcing pump, which
on the one hand attracts the  venous blood, and on the
other sends out the arterial.  There is  no doubt exag-
geration in this manner of considering it, though it would
be wrong wholly to reject the influence  of the heart
upon  the motion of the blood in the veins.  The capil-
lary  and  venous action are the  principal  causes of this
motion; but  the  contraction  of the  ventricles  should
be enumerated  among  the secondary causes.  One fact
will be sufficient to prove this.  Open a vein and observe
the jet of blood which flows from it; at the end of some
time, this jet will be no longer uniform, it will  be evi-
dently  raised,  and the blood will come out quicker at 
        VASCULAR SYSTEM WITH BLACK BLOOD.     109

each contraction of the ventricles.  This influence is then
real, though  much less evident than  in the arteries.

         Development of the Venous System.

   Page 425.—" The veins have in the foetus an arrange-
ment inverse of that of the arteries; they are in propor-
tion much  less developed."

   By applying to man the labours of Haller, Pander and
others,  upon the development of the blood vessels of the
chick,  it would follow from it  that  a part of the venous
system  is earlier developed than  the arterial system. The
first vessels that are discovered  are the  small branches  of
the vein of the  yolk, or  the umbilico-mesenteric.  This
vein itself, as well as the vena porta, is distinct when the
aorta hardly exists.  J. F.  Meckel  thinks nevertheless
that, from  the arrangement  of the sanguineous system  in
some monstrous foetuses, and the manner in which  this
system  is complicated in the scale of beings, it would  be
possible that the aorta should be formed  in man at the
same time  as the first veins, or even before  them.   If so,
this  artery must exist before the heart, and communicate
directly with the vena porta before the formation of  this
viscus.   With  this  exception only in regard to the um-
bilico-mesenteric vessels,  the veins in general are not
developed  till  after  the  corresponding arteries.  As  it
regards  the development of the pulmonary artery, what
I have  said in the vascular system with red blood may
be seen. 
110
ADDITIONS TO THE
MORBID  ANATOMY   OF  THE  VASCULAR  SYSTEM  WITH
                    BLACK BLOOD.

       I.  Alteration in the external forms.

  The veins, like the arteries, experience total or partial
dilatations ;  this is  what constitutes varices.  The  fre-
quency of this affection in the inferior extremities is well
known ;  the reason of it has been given above.  It is also
quite often met with in the veins of the rectum, the blad-
der and genital  organs,  and in  the sub-cutaneous veins
of the anterior parietes of the abdomen.   The deep-seated
veins are not exempt from  it, though they are much more
rarely affected than the  superficial ones.  Morgagni has
found the azygos vein considerably  dilated ; the jugulars
and  the  crural sometimes become  varicose.  In some
cases, the  whole venous system exhibits a very evident
increase.  Puschett, who has recently published in  Ger-
many a  very extensive treatise on  the  diseases of the
veins, has  insisted  very much on  this general dilatation,
which, in his opinion, performs  an important part in a
great number of diseases.  The  dilatation may, not as we
have  seen, be confined to a single vein, but extend to all
its divisions.  The  increase of size takes place then not
only  in the  transverse direction ;  the veins  form curves
which are evidently owing to their  increase  in  length.
Finally there  are  dilatations still  more limited  which
affect but a part of  the circumference of the vessel.
  The state opposite to the preceding, or the  diminution
of capacity of the  venous system,  is by  no means so
common.   Yet it is seen under some circumstances, either
in the whole system, or only in some veins in particular. 
       VASCULAR SYSTEM WITH BLACK  BLOOD.      m

This diminution can extend even  to obliteration.  There
are examples of the spontaneous obliteration of the venous
trunks themselves, as of the venae cavae, jugulars, &c.

         II.  Alterations in the  Organization.

   The inflammation of the  veins takes place under many
circumstances.   1st. It has  been seen  to extend a greater
or less distance after the operation of blood-letting.   It is
always on the  side  of the  heart that it is  propagated in
this case,  and- never on that of  the  capillary vessels.*
Death even may  be the consequence of it.  2d. Tying
the veins, which has been sometimes done in amputations
has been followed by inflammation, which, as in the  pre-
ceding case, extends towards the heart for a greater or less
distance.   3d.  Tying  the umbilical  cord appears  to have
produced the same effect.  Meckel the elder, and Osian-
der have related examples of it.  4th.  Veins affected with
varices and tied above  the disease have also exhibited this
phenomenon.   5th. In very extensive phlegmonous in-
flammations, in those,  for example, which come after par-
turition,   in the  abscesses  and gangrene which  succeed
them, the veins are often found more or  less inflamed on
the exterior as well as the  interior.   This inflammation
sometimes extends far oeyond the diseased part.
   There is  no  vein which  does  not  sometimes  exhibit
traces  of inflammation, from some of the causes  that we
have just pointed  out.   The disorders produced   by this
affection  are, a redness more or less  considerable on the
internal membrane, with a ihickening of the two other
coats;  purulent collections of different kinds  around the

  * This rule however is not without exceptions.  Abe rnethy has seen
the vein inflame below, almost to the wrist, after bleeding in the arm,
and remain sound above, that is to say, on the side of the heart. 
112
ADDITIONS TO THE
vessel  or even in its  internal cavity, fibrous concretions
which obstruct this cavity more or  less, sometimes even
the complete  obliteration of the  vein, in  some  cases  a
remarkable hardness, and at  other times ulcerations ; such
are the principal disorders  to which this affection gives
rise.
   It becomes  salutary,  on the contrary, when,  as after
venesection, it is limited to the lips of the  wound, and
does not extend beyond the degree necessary for its ad-
hesion.   Every one knows that these punctures heal with
the greatest ease;  it  is also known  that at the end of
twenty-four hours  the  means of union is still not very
firm, that it can even  be broken by  a moderate effort, and
that it is not till afterwards  that  there is a  real cicatrix.
The mechanism  of the union is  here the  same as  in
wounds of the other  textures, whilst as it  regards the
arteries, this union has hitherto been only observed upon
animals.   If we may credit Mr. Travers,  the  internal
membrane of the veins  does not partake  of their adhe-
sive inflammation.
   The  same author believes, that in  the  obliteration  of
the veins which follows  their transverse division, it is not
the adhesion of the internal membrane, but  the  thicken-
ing of  the parietes, which closes the cavity of the vessel.
His observations upon this subject should be repeated.
   Wounds produced by an external  cause resemble spon-
taneous ruptures.  Morgagni cites a case of  this kind, in
which  the azygos  vein  exhibited an  oval  opening in a
woman who died of phthisis.   The blood was  effused in
the thorax ; the vein, though partly flattened,  had still
the size of the vena cava.    Convulsive motions have ap-
peared sometimes to be the  cause of these ruptures.
   Wounds made in the parietes of the veins may affect
at the  same time an  artery  which is united  to them ;  if, 
     VASCULAR SYSTEM WITH BLACK BLOOD.       113

in this case, the external wound cicatrizes, the opening of
communication subsisting  between  the  artery  and the
vein, there will result from  it the disease described under
the name of aneurismal varix, in which the blood, pass-
ing from the artery to the vein at each contraction of the
ventricle, distends this last  and produces  in it a pulsatory
motion analogous to that  of the arteries.   Sometimes
there  is  merely a round opening, formed of the corres-
ponding parietes of the two vessels ;  sometimes there is  a
consecutive  false aneurism, which is found between the
artery and the vein.  It is in this last case that the dis-
ease deserves the name of varicose aneurism.   The bend
of the elbow is the most frequent seat of this affection, of
which various examples are found in  authors, particularly
in the work of Hodgson on the Diseases  of the Arteries.
   Bichat  has already remarked how rare osseous  trans-
formations are in the vascular system with  black blood  ;
it is even one of the characters which he has given to the
common membrane which  lines the whole interior of this
system.  Yet this membrane is not entirely exempt from
them.    Morgagni found  in  a  young  girl the sigmoid
valves of the pulmonary  artery partly cartilaginous and
already  exhibiting  the  commencement  of ossification,
M. Corvisart has many times met with this alteration in
these  valves, as well as in the tricuspid.   The veins them-
selves are susceptible of ossification  in old  people, espe-
cially on the side where they touch  an artery.   There is
sometimes found  in the veins small, hard, round bodies,
which might be taken at first sight for osseous produc-
tions.  Some have even supposed that they are  formed at
first in the parietes of the veins; others  have said that it
was in the substance of the valves ;  Hodgson thinks that
their primitive seat is on the  exterior of the  vein.  These
bodies, which I have many times had  occasion to examine,
              15                     # 
 114                 ADDITIONS,  &c.

 have appeared to me to be real concretions, phlebolithes.
 They are usually found in  lateral  dilatations in which
 the blood is stagnant ; there is observed in their structure
 nothing which resembles the osseous texture ; they seem
 to be formed on the contrary of layers superadded to each
 other,  and have around them a very evident  coagulum.
 They are found also of different degrees of consistence.
 The veins which exhibit this alteration the most frequently
 are those in which the course of the blood is the most ex-
 posed to being retarded ; thus it is very common in veins
 which  occupy the interior of the pelvis, the neighbour-
 hood of the arms, &c.
   The venous texture has not any morbid affection which
 is peculiar to it; it partakes of those of the  other organs.

         III. Alterations in  the Development.

   Are varieties in the situation, origin and  distribution of
 the veins  more frequent than those of  the  arteries,  as
 Haller thought ?  Meckel maintains the contrary, and that
 the veins seem  to have more varieties, only because their
 number is greater.   There  is perhaps exaggeration on
 both sides ; yet  it is  evident that  in the great trunks
the arrangement is much more constant in the veins than
in the arteries.
   There are veins in all parts as there are arteries.   The
following is a proof of it;  a false membrane, which was
found in  the  tunica  arachnoides,  and  adhered to the
 serous membrane only by one of its edges, at the superior
longitudinal sinus, and  was  entirely free elsewhere, was
injected with mercury, which  enabled me to  see  veins
going to this sinus.
% 
ADDITIONS
TO THE
CAPILLARY SYSTEMS.
  Continuation of the Arteries  with the  Veins,  the
                   Exhalants, fyc.

   Page 19, vol. 2d.—" It has been asked,  if there was
any  thing intermediate between the arteries and the
veins,  inspection proves that the capillary system alone
is there."

   It was formerly thought, in fact even since the beautiful
discovery of Harvey of the circulation of the blood, that
there was a texture intermediate between the last extremi-
ties of the arteries and the first  branches of  the veins.
This opinion was founded on  the fact that oftentimes in
injections, the substance pushed into the arteries, instead of
returning directly  by the veins, seems at first to be  infil-
trated  in the surrounding cellular texture.  It  was after_
wards perceived, that this infiltration was accidental, that 
116
ADDITIONS TO THE
 certain substances only, a solution of glue  for example,
 were capable  of  infiltrating, whilst others do not exhibit
 this phenomenon.  The existence of an intermediate tex-
 ture was then rejected, especially as no one  had seen this
 texture.   Finally, Malpighi appears to have  been the first
 who proved by microscopical examination, the direct con-
 tinuation of the arteries with the veins, so  well  demon-
 strated since by the  experiments of Spallanzani and espe-
 cially  of Leuwenhock.   At the present day  any one may
 see this continuation who will take the trouble ; for this
 purpose, the transparent parts of animals are chosen, as
 the mesentery of frogs, the tail and limbs of  tadpoles, th^t
 of fishes, &c.  Injections driven through the arteries not
 only return by the veins, but the reverse also takes place,
 if the valves do not prevent it.
  The continuation of the arteries in the exhalant vessels
 cannot exist unless  these vessels really exist; now, we
 shall see hereafter  that this point is  still very obscure.
 The communication with the excretories  is not demon-
 strated as it regards all the glands ;  there  are  some  in
 which  injections  have  not passed  from the  arteries into
 those tubes; the  microscope  has  not  yet shown us the
continuation of these two orders of vessels ; we know not,
if in the glands even in which they evidently communi-
 cate, there  be  not an intermediate substance.
  The last extremities of the arteries communicate also,
according to some, with the  lymphatics, at the origin of
these last; this will be examined  under the absorbent
system.

                  Erectile  Texture.

  Page 33.—" The spleen, the corpus cavernosum, in-
stead of presenting,  like the  serous surfaces,  a vascular 
CAPILLARY SYSTEMS.
117
net-work in which the blood oscillates in different  direc-
tions,  according to the  motion it receives,  exhibit only
spongy,  cancellated  textures, whose nature is  but little
known in which the blood  appears often to stagnate, in-
stead of moving," &c.

   The arrangement  of the  capillary system  in  these
spongy textures has been very well described  by many
modern  anatomists.   The  corpus cavernosum  has been
the particular subject  of their researches.   It  might be
thought  at first  view, that  it is a cellular or spongy tex-
ture infiltrated with blood ; when it is cut into, this fluid
flows  from  it and seems to come out  of the small open
spaces and not immediately from the vessels.  It is this
which deceived  Haller and the anatomists who followed
him,  and made  them believe that the blood was poured
out by the arteries in the  interstices of  the laminse and
fibres of the corpus cavernosum, from which it was taken
up* by the veins.*   But if on the  one hand, the arteries
are injected, they are  seen  to terminate by  very delicate
ramifications which  go precisely as  in  the other  parts ;
and by injecting the veins, on  the other, we easily per-
ceive, 1st, that they are  much dilated at their origin ;  2d,
that the species  of enlargements which they  occasion
have  very numerous  anastomoses, like the capillary sys-
tem of which they make a part.   It follows hence that
these  vessels  appear, as it were, filled  with  openings,
which makes them  resemble   meshes   communicating
together.  The erectile texture  of the corpus cavernosum
is  then formed of  small arteries and veins interlaced like

  *Such was the opinion of Bichat himself,  an opinion by no means
admissible, and which is abundantly refuted by whut is !i«.i - said o(
the structure of the corpora cave rnosa. 
118
ADDITIONS TO THE
the  capillary  net-work ; all the difference is that here
the venous branches are more developed and dilated in a
particular manner.   These enlargements  are so  unlike
cells, that they are only continued  with the veins, and
the internal membrane of these vessels is found in  them.
  Besides, this manner of describing the erectile texture
is not new ; Vesalius,  Ingrassias and Malpighi had seen
imperfectly its true arrangement.  John Hunter has said
positively that it was formed only of vessels.  Duvernoy
had the same idea  from the  dissection of the penis of the
elephant.  In  our time Mess. Cuvier, Ribes and  others
in France,  Mascagni,  Paul Farnese and  Moreschi  in
Italy, and Tieddmann in Germany have perfectly demon-
strated this fact, both in man and various other animals.
  In erection, the  blood is accumulated in this texture  as
Swammerdam is convinced; but we know not the cause
of it.   Duvernoy attributed this phenomenon to a contrac-
tion  of the veins.   Others have  said  that it was owing  to
the  entrance  of the blood  in  greater quantity  by the
arteries; it remains  to be explained by this hypothesis,
why this afflux exists.  Some have pretended that it was a
vital expansion of  this texture, and that the accumulation
of blood was only secondary.
  There are some  parts whose structure resembles  that  of
the corpus cavernosum, or which are susceptible of a sort
of erection more or less similar to its own.   This appears
to be the case with the spleen as to  structure, and even
as to phenomena ;  in fact, this  viscus exhibits a real mo-
tion of expansion  and  contraction,  1st, in experiments ;
when in a living animal, the course  of the blood in the
splenic vein is stopped, the spleen swells ;  it contracts  as
soon as the circulation is reestablished ;  2d,  in diseases ;
the paroxysms of intermittent fever are accompanied with
an evident enlargement of this organ, which goes  off when 
CAPILLARY SYSTEMS.
119
 the paroxysm is gone; 3d, it appears that the same thing
 takes place during digestion.  But it is especially to  the
 spongy texture of the urethra, the corpus cavernosum of
 the  clitoris, the  nipple  and the vascular texture of the
 nymphae, tfiat the name of erectile texture can be applied.
 The motions of the iris have been explained  by supposing
 it formed of  this texture.  The lips  exhibit something
 analogous.  Everywhere, moreover, the  arrangement of
 the venous system seems to indicate,  to a certain extent,
 the presence  of  a sort  of erectile texture,  as has been
 remarked by M.  Chaussier.   Injections show the  veins
 everywhere very evident at their origin, and giving rise
 to net-works with such fine meshes that they might be
 taken for the cells of a spongy texture;  the fleshy part
 of the fingers exhibits this  arrangement in  an  evident
 manner.

                Capillary Circulation.

   Page 36.—" The whole  doctrine of the mechanicians
 rested, as  we know, upon  the  great extent which they
 gave  to the movements of the heart/'

   What we have said of  the venous circulation  applies
 also to that of the capillaries ; the experiment which we
 have cited proves the influence of the heart upon this last
 as upon the first.  Further,  if in this experiment,  the
 artery is compressed, the jet of  blood  which comes from
 the vein lessens  and  becomes less i»apid.  Then  by sus-
 pending for a moment the action of the heart in relation
 to the vein, we subtract  one  of  the  causes which deter-
 mined the blood  to  flow out.  Now, what are  these
causes ? The same, nearly, as those  which  produce the
capillary circulation.  Then, there are recognized as causes 
120
ADDITIONS TO THE
of the capillary circulation, 1st, the peculiar action of the
capillary net-works ;  2d, the action  of the  heart.   We
should never lose sight of the fact,  that the heart may
influence this circulation in its own way.
      MORBID ANATOMY OF THE CAPILLARY SYSTEM.

         I.  Alterations in the external forms.

   The capillary vessels appear to increase in size under
two principal circumstances ;  1st, when the-course of the
blood is found interrupted in an arterial or venous trunk ;
2d, when this fluid is accumulated in a part from the  irri-
tation which it has experienced.
   After the ligature of the artery  of a limb, there takes
place, as is  well known, very important changes  in the
circulation  of this  limb.  All the blood which passed
through the tied  artery  flows  back at first  towards the
capillary  extremities of the  collateral branches  situated
above, and thus  arrives, by means  of the numerous anas-
tomoses of  the capillary system, to the branches situated
below the tied point.  The circulation is  then carried on
in a circumscribed space, almost exclusively by the capil-
lary vessels, which are dilated in proportion.  Injections
made  upon the dead  body show at this period an innume-
rable quantity of these  vessels, many of which  become
apparent only because the blood passes through  them "in-
stead of the serous fluids which they contained.   In the
living animal, this sudden passage  of a great quantity of
blood  through the capillary sjstem occasions  an increase 
CAPILLARY SYSTEMS.
121
of temperature and often even a redness of the skin, after-
wards one or more of these vessels become considerably
larger than the others, which return to their original size;
the phenomena pointed  out  gradually disappear.  There
usually exists  then two or three great collateral branches
dilated, which reestablish the circulation in the limb.
   The spontaneous obliteration of the arteries is followed,
like their ligature, by the reestablishment of the circula-
tion  by  means  of anastomoses.   The  same phenomena
take place in regard to the veins ; there is, as for the arte-
ries, an  increase  of the capillary net-works at a certain
period.   It is necessary  moreover, to distinguish  this
increase  of the capillaries, from that which takes place in
the anastomosing branches of a more considerable size,
and which have been noticed elsewhere.

         II. Alterations in the  Organization.

   The capillaries, unknown in  their structure,  are  also
unknown in the  alterations of their texture.   Contusion
seems  to weaken their  parietes;  at  least they are often,
in this case, enormously  distended by the blood ; concus-
sion appears to act in the same way.   The capillaries are
frequently ruptured, hence the various species of ecchy-
mosis, sanguineous infiltration, &c.   These vessels, divid-
ed in wounds, furnish at first blood, then venous fluids,
and then  a substance capable of concretion, which becomes
the base  of the cicatrix.

          III. Alterations in the Development.

   Capillary net-works are produced preternaturally, 1st,
in the production of false membranes; 2d, in  the forma-
tion  of cicatrices.  Stoll appears to  have been the  first
who remarked that, in some cases, the membraneous  lay-
              16 
122
ADDITIONS TO THE
ers which cover the inflamed venous membranes contain
very evident vessels and are continued with those of the
venous membrane itself.  John Hunter and M. Chaussier
have since  made the same observation.  Most authors
admit  that  these vessels  are  only  an elongation  of
those of  the  serous   membrane.   Mr.  Home  thinks
with John Hunter that they are developed in altogether
another way ; according to him, there is, 1st, a forma-
tion  of small bladders containing  only colourless or  even
gaseous fluids in the beginning ;  2d, union of these  blad-
ders and the production of a vascular net-work still desti-
tute of blood ; 3d,  finally  anastomosing between the ves-
sels developed and those of the inflamed  membrane, and
the entrance of  the blood into  the first.  Such appears to
be, in fact, the course of nature.  If we fill with mercury,
at hazard, a false membrane which does not appear to con-
tain vessels,  the metal is distributed regularly through it,
and takes the form of  ramified stria?, similar to the rami-
fications in leaves ; they are the vessels of the false mem-
brane,  which existed before communicating with those of
the serous membrane.   These  vessels exhibit even  after-
wards a diameter greater than that of the  vessels of com-
munication,  and a  peculiar arrangement different  from
theirs,  as I have convinced myself by injection.
   It is no doubt by  an analogous mechanism that the
vessels of cicatrices are produced.   Mr. Home  and M.
Bauer have  made microscopical experiments, which sup-
port this idea ;  I think  it  so much the more admissible,
as it accords perfectly with what we know of the forma-
tion  of the vessels in  the  natural development of the
textures.
   We  find in a disease described by Bell under the name
of aneurism by anastomosis, by Frier and the German
authors under that telangiectasis, this variety of form of 
CAPILLARY SYSTEMS.
123
capillary system  which  constitutes the erectile texture.
There is often a defect of conformation which the infant
has at birth ; such are most of those called nsevi materni.
This disease appears usually under the form of a tumour,
the extent, size,  colour, &c. of which vary.   A  whole
limb has been  seen  to be the  seat  of it.  The  texture
which  forms these tumours resembles that of the corpus
cavernosum; when injected  by the arteries,  it  is not
always  filled ;  injections succeed much  better  by the
veins.   The most ample details, however, on this subject
may be found in  the work of Hodgson, which has been
already cited. 
~> 
ADDITIONS
TO THE
EXHALANT SYSTEM.
        Arrangement of the Exhalant Vessels.

   Page 69.—" Let us reject then every opinion that dis-
regards anatomical observation, and let us endeavour by
this observation to ascertain what the exhalants are."

   It is evident, that if we are confined to strict observa-
tion, there are no more reasons in favour of the existence
of the exhalant vessels, admitted by Boerhaave and others,
than there is for that of the lateral pores imagined by Mas-
cagni.   It  is very true  that there exists  white vessels,
as Vieussens and Boerhaave, at  almost the  same  time,
thought, in this  sense  that the  blood  passes colourless
through many capillaries, which do  not  become visible
until their enlargement permits the red globules to  enter 
 126    ADDITIONS TO THE EXHALANT SYSTEM.

 them.  The existence of these vessels  is  especially well
 established  by an  experiment of Bleuland ; this  author
 injected by the arteries of the  intestine two substances
 differently  coloured,  one of which,  the  thinnest, went
 beyond the red vessels, into a net-work formed by  vessels
 of another order, which arise from the arteries and termi-
 nate in the veins; the coarser substance, on the contrary,
 filled the arteries and the veins only as far  as their direct
 communication.  Ruysch had admitted for a long time that
 injections colour  parts which are  not  naturally coloured.
 It is not correct, as has been pretended, that this difference
 depends only on  the quantity of the  blood  and not on
 the  nature  of this fluid ; for, when examined  by a mi-
 croscope, a single globule appears coloured.
  But these white vessels, as injections show, terminate
like the red by continuing with the  veins ;  nothing
proves that they go further.  What are we taught  in this
respect by the  fact  of the  exhalations,  that of nutrition
and that of transudation by the extremities of the arteries
in fine injections ?   That there  are  openings  at  these
extremities, by which the exhaled fluids, the materials of
nutrition and the matter even of injection  escape.  But
are  these openings met with  at the point of continuation
of the arteries with  the veins, or  are they the free ex-
tremities of an  order of vessels which extend  beyond ?
Here, as may easily be  conceived, observation is arrested. 
ADDITIONS
TO THE
ABSORBENT SYSTEM.
              Origin of the Absorbents.

  Page 95.—" It is not until  they have run a certain
course, that these vessels are cognizable by  our senses,
and that we  can consequently study them  in a general
manner."

  The following are the only anatomical views we have
upon the arrangement  of the lymphatics at their origin.
  1st. Cruikshank says that if we  examine  a  small in-
testine during  the  process  of digestion,  we. perceive
distinctly  on its  internal  surface,  the  orifices of these
vessels, terminated like a watering-pot  and  filled with
a chylous  matter  which  renders  them  more visible.
Hewson, Bleuland and Hedwig have  made observations 
128
ADDITIONS TO THE
analogous to this,  which  contradict,  indeed,  those of
Rudolphi and Alb : Meckel.
  2d. By injecting the surface of the liver, and by after-
wards  making  the mercury pass, by pressing with  the
finger, into the  smallest vessels, we shall  soon see it, as
Mascagni has remarked, come out of these vessels by small
openings and appear on the surface  of the serous mem-
brane.   These openings, it  is true, may be  only inorganic
pores or even crevices,  and not the natural orifices of the
absorbent vessels.
  3d. We have seen, in the liver and testicle, the mercury
driven  in at the  ductus  choledochus  and vas deferens,
return by the lymphatic  vessels, which  seem to prove
that these last are open  on  the  interior of these ducts.  I
have myself  had occasion to ascertain the correctness of
this fact.
  4th. As  to the  continuation of the lymphatics with
the extremities  of the arteries, admitted by the ancients,
the fact is  still  doubtful.   Most authors  explain  the
results of injections, by saying that they do not pass from
the arteries or the veins into  the absorbent vessels, until
after being effused into the  surrounding textures.  Mas-
cagni admits, moreover, that  the communication  can be
established  directly by the  orifices of  the  lymphatic
vessels open  on the interior of the  arteries.


 Venous Absorption.— Termination of the Absorbents.

  Page 108.—" Here, as in  so many  other  points,
physiology has need of great light."—There are  " many
probabilities  against and  many  in favour of venous  ab-
sorption." 
                  ABSORBENT SYSTEM.             129

  Before  the discovery  of the  lymphatic vessels, the
veins were generally  considered as the  only agents  of
absorption.  Afterwards Hunter and Cruikshank deprived
them of this property, to give it exclusively to the absor-
bent vessels.   At the present day, the idea of the ancients
is in part resumed, brought forward with new proofs by
Meyer, Messrs.  Magendie, Ribes and other modern phy-
siologists.  The following is one  of the most conclusive
facts.  Insulate  to a certain  extent  the artery and vein
of a limb, taking care to cut all the other living connex-
ions which unite it  to the trunk, and  then introduce  a
poisonous substance into the cellular texture,  the  animal
will immediately experience all the symptoms of poison-
ing.  Tiedemann  and  Gmelin have  proved by many ex-
periments that  all the substances recognizable by their
odour, colour or chemical composition, when taken  into
the stomach,  are  found  in  the blood of the  vena porta
with their peculiar characters.  It must be admitted then,
either that the veins have absorbent orifices open upon all
the  surfaces, or that  they  communicate  soon after their
origin with the absorbent vessels.  Abernethy has observ-
ed something similar to this last arrangement; he has seen
the  vasa efferentia going off from a  lymphatic gland in
order to go to a  vein, and the injection passing from the
first to the second.


         Structure of the Lymphatic Glands.

   Page 117.—"In  the  interior of these  glands, these
 branches,"  (absorbents,) "  very tortuous,  folded  upon
 themselves in different ways, occupy a great part of the
 peculiar texture of these  organs  which many thought  in
 consequence were nothing but an interlacing of the  ab-
               17 
130
ADDITIONS TO THE
 sorbents ;  an idea that is not proved, since  this  texture
 is not yet  well known."

   This idea, viz. that the lymphatic glands are nothing
 but the interlacing of the absorbents, is that  of Mascagni
 who regards them as entirely formed of vessels.   Gordon
 coincides in this opinion, which appears in fact the most
 probable, from the considerations we are aboutto offer.
   There are,  as may be  seen, two  orders of lymphatic
 vessels in the glands of this name ; some come to these
 glands, the others go from them.   These are the  vasa
 afferentia  and efferentia ; they are  distinguished  by
 their situation and  especially by the  direction  of their
 valves ; those of the first  have their  loose  edge nearer
 than  the other to  the gland ; it is the reverse in the
 second.  The number of these  vessels varies ;  they arc
 found from one to   thirty on each  side.   There  are, in
 general,  fewer  of the  efferentia than  the  afferentia,
 sometimes  as many,  rarely more.   In order to  see ad-
 vantageously the  arrangement of these  vessels  in  the
 peculiar substance of the  gland, it can be injected on its
 surface with mercury, or in its interior with  a  substance
 capable of  becoming solid.   1st. If  the surface be inject-
 ed,  either  through  the vasa afferentia  or efferentia, it
 exhibits on the one part, divisions ramified ad infinitum.
 and forming,  as it   has been said, two opposite capillary
 systems ; and on the  other, branches dilated,  enlarged
 and anastomosing a  great  number  of times, and forming,
 like the  preceding,  net-works  intermediate  to  the two
 orders of vessels and belonging to both.  2d.  The follow-
 ing arrangement is  found  in  the interior ; the vessels,
 filled  with  wax, appear even  to  communicate in  two
ways, at first by the  capillary extremities similar to those,
which, in the  sanguineous  system, terminate the arteries 
ABSORBENT SYSTEM.
131
 and commence the veins, and moreover by enlargements
 which cannot better be compared than to  the  analogous
 enlargements  which  surmount the  veins in  the erectile
 textures.   It  is in these enlargements that is  contained
 that whitish, thick matter, which Bichat and Haller place
 in peculiar cells, and which  is found more abundant  in
 children.
    All the glands of any size exhibit in an evident manner
 the structure we have just pointed out; it is distinguished
 even  in  many of the  small ones, though  it is less  ap-
 parent in  them.   There is  but very little cellular  tex-
 ture in these glands, and it is very  delicate if we  except
 the  fibro-cellular  membrane  which surrounds  them.
 Their veins are in very considerable number,  especially
 in this membrane.  Mascagni, Walter and others have
 not been able to trace nerves  in them.

 Properties of the Absorbents.—Sensible Organic Con-
                       tractility.

   Page  120.—" The sensible  organic  contractility  is
 then at least doubtful in them, if it exists  it is very ob-
 scure and at most  to be  compared  to that of the  dartos
 muscle."

   Schreger has seen the absorbents in  many experiments,
 contract under the influence  of irritating  agents.  Not
 only the concentrated acids, but also  the  butter of anti-
 mony, alkohol and hot water, which  we  cannot suspect
 of aeting  by  the horny hardening, have  produced this
effect.   The action  of cold water is  often  sufficient  to
obtain the same result.   Mechanical irritations have been
followed by alternate contractions and  dilatations.  Under
all  these circumstances,  the  contraction  is  propagated 
132
ADDITIONS TO THE
always beyond the point touched, to a  certain extent.
These  phenomena, which are very striking during  life,
are also observed after death ; they continue even  more
than those of muscular irritability.   If we add  to  this
that the  thoracic  duct  is often, after death,  broad and
flattened, though  empty, whilst during life  it  is almost
always found contracted  and hardly visible, we  must
admit that  the lymphatic vessels  have a  power of vital
contraction different from  that which  they possess after
death.  It must be by this power that they contract and
empty themselves more or less completely when  opened
between two ligatures ; and in fact Tiedemann has ob-
served that this  phenomenon, very evident during life,
in the thoracic duct and some other  trunks, which then
empty themselves by a real jet, is very slight after death.
     MORBID ANATOMY OF THE ABSORBENT SYSTEM.

       I.  Alterations in the External Forms.

  The absorbents  appear to be able to be  dilated preter-
naturally.   Some  authors consider as dilatations of this
kind the  species of hydatids that are observed especially
on the plexus choroides, in which they are arranged in a
line, united to each other by filaments.

         II.   Alterations in the Organization.

  Inflammation of the lymphatic vessels is followed, like
that  of the  veins, by suppuration, albuminous effusion, 
ABSORBENT SYSTEM.
133
obliteration, &c.  It has been  already discussed as well
as that of the glands.   The wounds of these parts heaFin
general quite early  ; it is not known if it be with an ob-
literation  of the vessel;  the cellular texture no  doubt
contributes much to the process of reunion.  This process
is sometimes  very  slow  in  the glands ;  thus it is often
preferred to remove them in  operations, for fear that their
swelling would  separate the  edges of the wound and re-
tard the progress of cicatrization.  Ruptures, analogous
to those which take place in  the  veins, have been seen in
the absorbents ; Assalini and Th. Bartholin relate examples
of them as it respects the thoracic duct.
   The  lymphatic glands  are frequently the  seat of the
transformation  to bone, even at an age  not  greatly ad-
vanced.  Their  ossification has commonly taken place in
one part only of  their extent.   The  frequency of the
tubercular  disease  of these  organs is known ;  this is not
the place to describe this affection.

        III.  Alterations in the Development.

   The  anatomical  varieties  are  very numerous in the
lymphatic  as in the  sanguineous system, besides those
which  are purely  accidental and which  depend on the
kind of death, the  previous disease, &c.   These varieties
extend  to the principal trunks as well as to  the secondary
branches, to the glands as well  as to the  vessels.   Thus
the thoracic duct is sometimes double, at least in a certain
part of its  course  ; the two branches then  often  unite
again and  thus  enclose a kind  of  islands.  Nothing  is
more variable than  the terminations of this  canal  at its
superior extremity : it is  seen sometimes single,  some-
times pouring  the  lymph by two or even three orifices
into the left sub-clavian vein, sometimes instead of open- 
134     ADDITIONS TO THE ABSORBENT SYSTEM.

ing into this vein, it goes to the jugular, the right sub-
clavian, or  sends  a  branch to the vena  azygos.   The
glands do not vary less in their number and situation.
  Inspection has not yet demonstrated lymphatic vessels
in the  preternatural textures,  such  as cicatrices  ;  yet
absorption supposes them there, unless we prefer to have
recourse to that of the veins. 
ADDITIONS
TO THE
OSSEOUS SYSTEM.
         Intimate Structure of the Bones.

  Page 160.—" Let us consider the compact texture as
an assemblage of condensed fibres, not separated by lay-
ers, which we can only consider as imaginary."

  Much has been written upon the intimate structure of
the bones, upon that of the compact texture in particular.
Malpighi admits that there are laminae and fibres in this
texture.  Gagliardi  has described minutely the osseous
pins ; there seems to be some truth in his opinion, be-
cause we distinguish in fact in the bones, fibres which go
obliquely through their substance.   Albinus, who is  fol-
lowed in this by most modern anatomists, says that there
are only fibres in the osseous texture, parallel in the long
bones and radiated in the broad ones.   Finally, if we may 
136
ADDITIONS TO THE
believe  Scarpa, there is nothing but small spaces in the
compact substance of the  bones as in the spongy sub-
stance.  Michel Medici has already combatted this idea
and thinks with the  ancients that it is under the form  of
laminae  that the osseous texture is arranged.
  By confining  ourselves to the examination of the facts
alleged for and against these different opinions, we see, 1st,
that the  existence of the fibres is by no  means  demon-
strated by the linear  appearance which the osseous parti-
cles take at their  development; in fact, this arrangement
does not continue long;  in the broad bones, for example,
these pretended  fibres, which  then extend to the middle
of the substance  of the bone are afterwards changed to  an
areolar  texture.   There  are however fibres in the bones,
as we see after having deprived them of their calcareous
matter.   2d. We may be  convinced even that there are
laminae, by taking a long bone softened  by an  acid and
macerating it in  water;  its compact texture separates at
the end  of some  time into distinct laminae, united by fibres
which pass obliquely from one to the other.  3d. In this
experiment, the laminae often finally resolve into filaments
and the whole bone at the same time becomes  spongy.
From this last.fact, and  from  this, that in many diseases
of the bones, the compact substance becomes spongy, as
well as from the circumstance, that' it evidently takes this
appearance when, as Troja has done, a swelling of a long
bone  is produced by introducing a  foreign body into  its
medullary cavity.  Scarpa concludes that the areolar struc-
ture alone exists in  the  bones of which we have spoken.
This  conclusion is not accurate, since besides the areolae
or small spaces, maceration  shows in the bones laminae
and distinct fibres.   It  is true that, if  this maceration  be
very  long continued, it converts the fibres themselves into
a substance, as it were spongy, into a kind of mucus. 
OSSEOUS SYSTEM.
137
  It would  seem then  that it is by having had regard
only to a small number of facts at a time, that each author
has explained, in his own way,  the arrangement of the
osseous particles, and that we ought to admit in the bones
laminae, fibres, and areolae or small  spaces; some are more
evident in the spongy texture, others are more developed
in the compact substance.

Arrangement of the Pores of the Compact Texture of
                      the Bones.

  Page 160.—" Such is the intimate juxta-position of the
fibres of the  compact texture, that they leave between
them only  pores  hardly sensible to the naked  eye,  but
which become so however  with a glass and which the
medullary juice and vessels fill."

  These pores are in many places real tubes which  con-
tain marrow and blood-vessels.    Havers,  Monro,  andj
latterly, Howship  have described  them.   They are T^„
of an inch  diameter.   Most of them are parallel  and
united by others whose direction is transverse or obliqua
to the first.

        Composition  of the  Osseous Texture.

  Page 167.—" Upon  this point," (the composition of
the bones,) " I refer to  chemical books, especially to the
great work of Fourcroy."

  The human bones contain, according  to M. Berzelius,
in 100 parts, 1st, 32,17 of gelatine  and 1,13 of blood ves-
sels ;  2d, 51,04 of phosphate of  lime, 11,30 of carbonate
of lime  and 2,00 of the fluate  of  lime; 3d, 1,16 of the
             18 
138
ADDITIONS TO THE
phosphate of magnesia;  4th, 1,20 of soda, hydro-chlorate
of soda and  of water.
   This  analysis, hitherto  the  most  complete,  does  not
agree entirely   with  those of other  chemists.   Thus,
Fourcroy and Vauquelin have recognized the existence
of the oxyds of iron, and  magnesia silex and alumina in
the bones; on the contrary,  they have not found fluoric
acid in them.  Besides, the chemical composition of the
bones exhibits   many differences not  only according to
age, sex  and individuals, but even  in  the  different parts
of the body.  The analysis of M.  Berzelius was made
upon the femur of an adult.  But the teeth evidently
contain  much more earthy  substance ;  it even appears
that it is so with the petrous  portion  of the  temporal
bone.  Various  other examples of this kind are recorded
in the Anatomy of Monro, from the new  researches of
J. Davy.
   In an  anatomical point of view, the bones are composed
essentially of a  peculiar  fibrous texture  in the areolae or
small spaces of  which the calcareous substance is found
deposited.   It is this  texture that is obtained by treating
a  bone  with acids.  The  residuum of this operation is
not a cartilage,  it  has neither its  whiteness,  consistence
nor composition ; flexible like the ligaments, it very much
resembles the fibrous  organs, from which it differs only in
this, that ebullition transforms  it more easily to gelatine,
and that  maceration softens it quicker.  This texture con-
tains all the organic  elements  of  the bone.  We cannot
then consider it  merely as  gelatine, and say that the bones
are only a mixture of this substance  and calcareous mat-
ter, as some authors  have done.  This  expression is so
much the less  proper, as  the gelatine does not  exist, as
far as it appears,  completely  formed in  the bones, no
more than  in the other animal matters, since it always 
OSSEOUS SYSTEM.
139
requires the aid of ebullition to obtain it.  Besides, if we
boil glue and calcareous matter, there results from it only
an unorganized compound, brittle and very different from
the osseous texture.

                Veins of the Diploe.

  Page 168.—" The accompanying veins of these arte-
ries" (the arteries of  the spongy texture) " can  hardly
be seen."

  Very large,  but insulated  veins exist in some parts of
the texture of the cells.   They are contained in peculiar
venous  canals, which Hippocrates pointed out, and which
have since been very well described and injected  by M.
Fleury.   These veins  form very numerous anastomoses;
they are especially apparent in the diploe of the bones
of the cranium  but they are also found in the ossa  ilii, in
the substance of the vertebrae and in the extremities  of
the long bones.   Their size is greater in old  people.


         Development of the  Osseous System.

  Page 206.—" I would observe that the arteries, which
have so great a tendency to ossification,  are not  so evi-
dently gelatinous as many other substances which ossify
much less easily, as the tendons  for example."

  Duhamel, J. Hunter, Nesbith, Reichel, Stenff and many
others  have made known many interesting  facts  which
deserve to be recorded here.  The natural  development
of the  bones  only will be treated of,  the preternatural
belongs to morbid anatomy. 
140
ADDITIONS TO THE
   The cartilaginous state  is not always  distinct.   The
bones of the cranium really have no pre-existing cartilages.
We shall see that it is the same with regard to the middle
of the long bones.
   The osseous state commences about the time stated by
Bichat.   Stenff has found the first rudiments  of  it at
forty days.   I have seen some  osseous points in embryos
of thirty days or near  that period.   The  clavicle and the
jaws appear first;  then successively and with some days
interval, the humerus and the femur, the  bones of the leg
and  those  of the  fore-arm,  the ribs,  and vertebrae, the
bones of the cranium, &c.   The sternum, the ossa wor-
miana, the  patella, and the  bones  of  the carpus are the
last that are ossified.  This order is not however confined
to any rule ; thus  all those,  which it has been attempted
to establish, are for the most part false in their application.
The only one  which has any real foundation is, that the
long  bones generally  precede the  broad ones  in  their
development, though  there  are  exceptions.  But  as to
the influence which  some authors  have  given  in  this
respect to  the  proximity to the heart  and to that of the
nervous system ;  as to  what others say of the more or less
early development of the bones according  to the degree of
importance of their functions in man,  or,  as some  think,
according  to their  more or less intimate connexion with
the phenomena of life in  the different classes of animals,
nothing of all this  is founded upon observation.
   Great changes take place in a cartilage which is con-
verted into  bone.   Vascular tubes, which  could  not
before be discovered in them, are developed.  Colourless
in the beginning, and irregularly arranged, they are after-
wards ramified like the arteries, and traversed with  blood.
The colour of this  fluid manifests itself by degrees ; these
tubes  however do  not appear to contain  it directly ;  the 
OSSEOUS SYSTEM.
141
vessels of the cartilage injected  seem rather merely to line
their parietes ;  this kind of vascular  membrane, which
covers them, has  even been considered  as  furnished to
secrete the osseous substance.   These tubes are very well
seen in the short  bones and the extremities of the long
ones.   The osseous points, the  development  of which
follows closely that  of the vessels, is at first merely an
union of filaments of extreme delicacy, which it is easy to
insulate by burning the cartilage; a kind of flake formed
of the calcareous matter is then  obtained.  As the ossifi-
cation advances the vascular canals are effaced ;  no more
traces of them  are found as soon as the epiphyses become
solid.
   The action of the blood vessels is then increased in the
ossification of the cartilages.  But do these last experience
any other change  in their texture than that which results
from the deposition of an earthy substance ? or is the or-
ganic matter renewed, as some authors  have thought ? It
is necessary in fact that the cartilage should undergo  a
very  great  change, if it does  not entirely disappear, in
order to become  bone ; for it  contains,  as  we shall  see
hereafter, scarcely any thing  but water, cellular texture
and albumen,  whilst the bones are formed of a fibrous
texture united to a saline substance.   There  is then  a
very great difference between the composition of the first
and that  of the second, and  it cannot  be said  that  the
bones  are  merely cartilages, with the  addition  of  calca-
reous matter.  Whatever may be the materials of  ossifi-
cation, it is the arteries which bring them and pour them
out, either  by  exhalant extremities, as Bichat thinks, or
by lateral pores, which is the opinion of Walter.  These
vessels do not  perform the  part, which Nesbith, Reichel
and W.  Hunter attributed to  them, of giving place by
their ossification  to that of the  cartilage.  The regular 
142
ADDITIONS TO THE
lines which the bones exhibit  in  their development and
which have imposed upon these anatomists, by no means
follow the  course of the blood vessels.  We  shall be still
less tempted to admit the hypothesis of Mascagni,  who,
regarding the cartilages as entirely formed of lymphatic
vessels,  supposes that in their ossification these vessels
are merely filled with calcareous matter.
   In the long bones, the first osseous point appears  from
the fortieth to the sixtieth day,  a  little sooner in the cla-
vicle.  The small  cylinder which it forms  is then the
only solid part of the bone ;  all the rest is still  mucous.
It is  not until from the sixtieth to the seventieth day that
the cartilages of the extremities appear; when these last
are ossified,  which  does not take place till much later,
there  is formed between them  and the body of the  bone
vascular canals similar to those  which occupy their  inte-
rior.   There is then this  remarkable difference  between
the bodies and extremities of the long bones,  that the
cartilage  cannot be  distinguished in the first as in the
second.   In the middle,  the  osseous  texture seems  to be
formed entirely of one piece on the  internal face of the
periosteum ; this texture is evidently cartilaginous in the
beginning at each extremity.
   The ossification  of  the  broad  bones of the  cranium
begins at about two months and a  half.  The osseous
points are at first scattered in the  thickened  mucous sub-
stance  which  represents the bone at this period.  They
afterwards  unite and take the form  of irregular net-works ;
it is not till later that they have that of osseous rays, still
covered with mucous substances  on  their two  surfaces.
These rays disappear when the two  compact laminae are
formed ;  they are changed into the texture of the cells.
   The increase in  length  of the  long bones takes  place
near their extremities ;  the middle has no part in it.   An 
OSSEOUS SYSTEM.
143
experiment, for which we are indebted to John Hunter,
proves this ; if the body of one of these bones is  perfo-
rated  in two  different places,  and the animal is  killed
some time after, the two openings are still at the same
distance from  each  other, though  the bone  may have
increased in length.  They would, on the contrary, be
further apart, if the growth took place in the whole  extent
of the bone.  Another fact confirms this.  In the experi-
ments with madder, the  colour appears in young animals
only in the space which separates each extremity from
the body of the bone ; the rest is only red at the surface,
unless the animal has been fed for a long time with this
substance.   Whilst a cartilaginous layer exists between
the body and the extremity, we consider that the growth
must  take  place  at the  expense of this cartilage.  But
when it is once invaded,  it must be admitted that there is
a deposition of osseous substance in this place, preceded
at most by the mucous state.   The growth in length con-
tinues until the epiphyses are united to the body  of the
bone, which takes place at about the age of twenty-one.
A delicate  lamina of compact substance is at  first inter-
posed between the body and the  extremity ; this after-
wards disappears and the continuity becomes perfect.
   The  three species of bones  grow  in thickness much
beyond the term of their growth in length,  as  has been
already said.  New layers are incessantly added to their
surface, as is shown by the colour of this surface from the
continued use of madder.   If the use of this substance has
been alternately discontinued and  resumed, the external
layers of the bone are alternately red and white ; whence
it must be  concluded  that they were  formed during the
continuance of the experiment.  The osseous substance is
produced there as in the preceding case without pre-exist-
ing cartilage, and perhaps by passing through the mucous 
144
ADDITIONS TO THE
state ;  but there is no  interstitial  deposition, as in com-
mon nutrition ; it is  rather a sort of juxta-position.  This
does not prevent the nutrition from taking place in the
bones  the  same way  as in the  other  parts.   The  use        J
of madder for a considerable  time,  so  as  to obtain the
effect noticed by  Bichat,  is a proof of it.  There  are
also  cases of preternatural  growth, both in length  and
thickness, which appears to arise from  a real excess of
nutrition.
  At the same time  the bones increase  on the exterior,
their  internal  cavities  enlarge ;  which  occasions  the
parietes of the medullary canal of the long bones to remain
in nearly the same  proportion of  thickness, as  long as
their growth  without and their diminution within  coun-
terbalance each other.   The bone gains on one side what
it loses on the other.  It is not  the same  in old  age.  The
growth in thickness  does not continue,  and the  internal
dilatation does ; there results from it an extreme delicacy
of the parietes of the medullary cavity.  This cause is
one  of those  which render the  bones of old  people so
brittle.
  Some important changes take place in the osseous sys-
tem in old age.  The broad bones diminish in general in
thickness.  Their texture of the cells disappears  and the
laminae of compact  substance, which it kept  separate,
come together ;  this  is what is  often seen in the parietal
prominences, in which it is so much the  more striking as
these prominences are replaced by a depression.  Some-
times  the broad  bones seem to  have increased  in  size,
because their texture is, if we may so say, rarefied ; deli-
cate laminae  which pervade it, give it  this appearance.
In the short bones, the external compact substance dimi-
nishes ; the areolae of the spongy texture are on the con-
trary more evident.   The  long bones, besides what they 
OSSEOUS SYSTEM.
145
lose of their thickness, seem also to experience  a real
shortening.   Finally, the change  of  composition  which
takes place in the osseous texture  takes from it much of
its  elasticity.   The bones of young subjects are flexible
to  a certain extent; we see that at this age the long
bones bend anrl the broad ones yield under certain cir-
cumstances.  The same oauses will produce a fracture in
an  adult, and for a stronger reason in an old person.


 Second Dentition considered at the period of Cutting.

  Page 219.—" The second molar" (of  the first denti-
tion) " remains, as we have just  said ; it is the first of
the great ones" (of the second dentition.)

  This is an evident contradiction, and must have escap-
ed Bichat from want of attention,  or else it  is a  typo-
graphical  error.  It is  said  above that the  first denti-
tion is  composed  of twenty-four teeth,  of which four
molars in each jaw are cut towards the end of the second
year, and two other molars towards the age of four years.
It is then these last, or the  third of the  first  dentition,
which form in  the second the first large ones.  The new
small molars take the place then of two teeth of the same
nature, and  not one alone.   All  the difference is, that
these new  small molars are much less strong than  the
teeth to which  they succeed ; these resemble very  much
the great molars.
19 
146"
ADDITIONS TO THE
      MORBID ANATOMY OF THE OSSEOUS SYSTEM.

        1.  Alterations in the External Forms.

   Swelling of the bones is of many species.   1st. There
are tumours which seem to  be deposited, as it  were, on
the  surface of the  bone, so that this is perfectly sound
below ; such are most exostoses.   This affection appears
to  depend, in  many cases, upon an inflammation of the
periosteum, in  consequence of which  this  membrane is
detached, and  secretes from  its internal face  a matter
which hardens and becomes confounded with the texture
of the bone ; a sort of periostosis precedes the formation
of the osseous tumour.   This  is more or less voluminous
according to the extent of the inflammation.  If the in-
flammation be circumscribed, there results from  it what
are called  nodes.   These tumous are  at first  very  dis-
tinct from the bone ; afterwards maceration  still detaches
them from it, and they are seen  holding to the  perios-
teum ; it is not until a long  time that  they  appear to be
continued with the osseous testure ; it may  then be  seen
by the microscope  that their vessels have not the same
arrangement as those of the  rest of the bone, and  do not
appear to be an elongation of them. When on the con-
trary the periosteum is inflamed for a great  extent, enor-
mous laminae are produced and give rise  to the exostosis
called lamellated;  the  bone is  entire beneath these
laminae as in  the other cases.   2d. Some exostoses  have
their seat in  the  bone itself, and are produced  by a de-
velopment  or separation of its most superficial  laminae.
3d.  The whole bone  is stretched,  becomes  thinner  and
is  considerably dilated  in  spina ventosa.   4th.  A'real 
OSSEOUS SYSTEM.
147
excess of nutrition  is the  cause of the increase of size,
when  there is joined with it an  increased  density, or
when  the density remains  the  same.  This is what  is
seen in exostoses that resemble ivory, and in  some  cases
in which the whole of the bone  appears to have increas-
ed at once in thickness  and consistence.   To  the  same
cause may be referred the  increase in  length  which the
bones of scrophulous individuals  sometimes undergo, that
in breadth  which the bones of the cranium,  of the max-
illary sinus exhibit, in affections  of these  cavities.   This
preternatural growth, which takes place in one or  many
bones  whilst the  others  do not  partake of it, is not
effected by a  mechanism analogous to that of the natural
development.  There is here an interstitial  deposition,
and not a formation of successive layers.
  The increase  in substance may be  confined to the in-
crease of the density of  the osseous  texture.   Enostosis
or internal ossification, in which  the cavities of the bones
are effaced, is an example of this.  The bones of rickety
subjects  exhibit an  analogous phenomenon, in  the  com-
pactness  which their curvatures  acquire on the concave
side.
  A state opposite to the  preceding is the  species of
atrophy which this  texture experiences when  absorption
begins to destroy it, either on the interior, as takes place
in old  age, or on the exterior,  as has  been  sometimes
observed.  According to Howship,  to whom avc are in-
debted for  new researches  upon the  alterations of the
bony  texture,  the brittleness  of the bones depends in
some  cases, in  syphilis,  for  example, upon an  alteration
of this kind, a sort of internal absorption which transforms
the  compact  substance  into a  spongy  texture.   This
author distinguishes the brittleness which arises  from
this  cause from that  which  comes  on, for example,  from 
148              ADDITIONS TO THE
scurvy and  scrophula.  This last  is generally attributed
to a defect in  the proportion of the constituent elements
of the osseous texture ; but there appears to  be  besides
an alteration of the animal matter.
  The mollifies ossium resembles brittleness very much ;
both of them are often met with in the same bone.  Mol-
lities  is of  two kinds.   One  affects  adults ;  the  bones
which are the  seat of it become soft and flexible, and are
bent by the  effort of the muscles alone ;  in the  dead body,
the scalpel  cuts  them easily.   Desiccation  and  stewing
show  that there is an evident predominance of gelatinous
substance  in these bones, which is also indicated by their
colour and appearance.   The  other species of mollities,
peculiar to children, differs from the  preceding in many
respects.
  The bones,  compressed  by  neighbouring  tumours, ex-
perience various changes in their shape.  These tumours
often  also destroy  them in part, perforate them and wear
them  out to  a  greater or less extent.  This  happens
especially to  those  which are agitated  by  a pulsatory
motion,  such  as from  aneurisms.
   The connexions of the bones, or the  articulations are
the seat of various affections which change  more  or  less
the relations of the articular surfaces.  The consolidation
of the immoveable articulations, luxations and anchylosis
of the moveable articulations, exhibit  examples of them.
Preternatural  connexions sometimes take place between
the bones, as is seen in false articulations.   Among these
last, some succeed to luxations,  and deserve the  name of
supplementary  articulations ;  others, which  are in
consequence of fractures, which are  formed by  a single
bone  divided into  two fragments, are supernumerary
articulations.  1st.  When a luxated bone has  not been
reduced,  it  may form for itself  a new cavity in the place 
OSSEOUS SYSTEM.
149
it  occupies.  This cavity gradually acquires a  suitable
depth ;  an  edge, at first cartilaginous, and afterwards
osseous,  is  formed  on  its  circumference;  the  cellular
texture  thickened around the surface  represents a sort
of fibrous capsule,*  which contains a viscid fluid a little
less  unctuous than  the  synovia.   A  fibro-cartilaginous
periosteum covers the new articular cavity.   The old one
is altered and generally diminishes in extent.   2d. When
the two ends of a fractured bone do not  unite, either on
account of their  mobility, or from  any other cause,  the
new  relations  which they  contract  resemble in some
measure an  articulation,  though  in a less degree than in
the  preceding  case.  Most  often  in fact, the  fragments
hold together only by a kind of fibrous  intermediate lines.
In some cases nevertheless their extremities become round
and  are encrusted with^ cartilage,  and  a fibrous capsule
surrounds them.  In some fractures of the  neck of the
femur, the  inferior  extremity has been seen to  form a
cavity in  the superior; this case  might be confounded
with the separation of the epiphysis.

        II.  Alterations in  the  Organization.

   But little is known of the effects of  inflammation upon
the osseous texture.   It  is certain however that the bones
suppurate.  They exhibit  this  phenomenon  in  caries, a
disease whose nature is still  unknown,  and  which appears
to be in many cases a real  necrosis.  In what  is  called
white swelling, and which  certainly  comprehends very
different affections, something analogous is  often seen  in
the  articular extremities.   They are  then  the original

  * Bichat speaks of this capsule  under the synovial system, to which
it seemed to him  to belong rather than to the  fibrous system.  The
fact is it has not always  the same  appearance in different cases. 
150
ADDITIONS TO THE
 centre of the  disease.   The  spongy substance  is  at first
 softened, penetrated with vessels and then infiltrated with
 a reddish serum.   The  bone afterwards suppurates, and
 fistulas  are  formed in  its  interior,  which  are  directed
 sometimes towards the  external compact substance, and
 sometimes towards the   articular cartilage.  In  this last
 case, the cartilage, till then sound, is detached from the
 bone, becomes thinner and is  perforated with holes ; and
 what proves that the disease  begins at the  bone is, that
 the opening remains smaller on the free surface  of the
 cartilage than on its adherent side, as has been well seen
 by Messrs. Palletta and Brodie, who have described  this
 affection, and as I have myself ascertained.
  Gangrene of the bones is  necrosis.  It is followed by
 the  same phenomena as that of the soft parts, only  it
 requires a longer time for the inflammation, suppuration
 and  separation of the dead  parts, which here  take the
 name of sequestra.   But  this necrosis varies  more-
 over  from  its extent, as well  as  from  its seat.   It  is
 usually  the  result  of the destruction of the nourishing
 vessels of the  bone, from the detachment of the perios-
 teum or the  destruction of  the  medullary  membrane.
 When it  is the  medullary  membrane which is  injured,
 the necrosis only affects  the internal laminae of the  bone ;
 the sequestrum is then contained in the  medullary  canal,
 and  has the thickness of the  bone to go through before
 it can be thrown  off.  But in other cases, the periosteum
 is inflamed at the  same time  and is separated from the
 bone ; this  is   then  affected  with necrosis  in its  whole
 thickness, and  there  take place  all the phenomena de-
 scribed  in  the article upon  the medullary system ; the
periosteum secretes a new bone, which surrounds the dead
 one.   Here this membrane must have remained uninjured,
for if it  were  destroyed  there would be no regeneration. 
OSSEOUS SYSTEM.
151
 It is without cause  that Scarpa and others  have denied
 this regeneration, and have pretended that what has been
 regarded as a new bone was always a part of the old  one,
 dilated by inflammation and which the necrosis had spared.
 The sequestrum has precisely the form of the  old  bone ;
 all the prominences  and  the most superficial depressions
 are found  in it; the numerous  specimens of this kind
 that are in  existence leave  no  doubt upon the subject.
 What  has  perhaps  imposed upon the authors  we have
just mentioned  is,  that the dead bone  is  worn  on its
 surface and covered  wTith inequalities.  The new bone has
 an irregular  form, and resembles  rather  an exostosis or
 a kind of vegetation, than a bone which existed originally.
 Finally, in the broad  bones, such  as the  scapula, this  is
 still more striking ;  there exists then two  bones of  new
 formation,  one external, the other internal, and  the old
 bone which  is dead, is contained  in  the space  between
 the two.
   The separation  of the  periosteum  and  the denudation
 of  the bones, which is the  result of it,  are not always
 followed by  necrosis, when  they take  place  only  to a
 certain extent.   If the bone has not been much contused,
 if the subject be young and the  integuments be reapplied,
 an  immediate reunion  is  obtained by the  effusion  of a
 coagulable  matter.   This  matter exhibits  at a certain
 period, irregular  osseous points, which have given origin
 to the  belief in insensible  exfoliation ; these  points are
 afterwards  effaced.
   Solutions of continuity of the bones, or fractures differ
 according as there is at the same time a wound in the soft
 parts, or these parts still cover the  place of fracture.  The
 phenomena are entirely different in the two cases.   It  is
 only to fractures  with denudation that must be  applied all
 that has been already said  upon the formation of  callus. 
152              ADDITIONS TO THE

In these only arise the fleshy granulations which after-
wards  form the basis of the  cicatrix, whether there  has
been  exfoliation by denudation or  not.  In  the others,
there are the three periods that  have been  pointed out;
1st,  a period of  exudation ; 2d, a period of tumefaction ;
3d, a period  of reunion.
  First period.  The osseous texture cannot  be divided
without the  flow of  blood  from the open vessels; thus
there is  effused at first a certain quantity of  this fluid
between  the two  fragments ;  this  quantity is  usually
inconsiderable, and the  blood  stops of itself at the  end
of a short time.   Another fluid succeeds  it; this is of a
serous nature and of a slightly viscid consistence.  The
effused blood gradually loses its red   colour.   Reunion is
effected in  the periosteum, the  medullary membrane  and
in all  the  other soft  parts which have  suffered by the
effect of the fracture alone.
  Second Period.  These reunited soft parts, the perios-
teum in  particular, inflame, swell and separate  from  the
bone ;  hence a tumour which is visible externally.  This
tumour is in  great  measure formed  by a coagulable sub-
stance effused under the periosteum and  between its  in-
ternal  laminae.   Osseous  points  are formed in  this sub-
stance and  finally take entire possession of it; the carti-
laginous state is hardly sensible, and exists  at  the most
but  in some points.   For the want of periosteum,  the
cellular texture  becomes the  seat of this ossification, as
has been seen by Macdonald.   The  medullary membrane
is also ossified.
   Third Period.   Hitherto scarcely any thing  has been
done in  the bone  itself; only the  two  ends  are found
joined externally by a sort of clasp, and  internally by a
plug which shuts up the medullary canal.  But this union
has only a slight degree of solidity; and if the  bone  he 
OSSEOUS SYSTEM.
153
again subjected even to inconsiderable efforts, the callus
will  yield  or  bend, and  even break.   The  process of
reunion is  carried on  in the fragments themselves ; the
intermediate  substance which  filled  the  space  between
them,  hitherto fluid becomes gradually more consistent,
and is penetrated with  vessels which are continued with
those of the periosteum  and  even  of the bone.  This
substance is not long in being  ossified ; it is not known
precisely in  what  manner, though  vessels  have been
clearly seen to  be  developed  in  it.  At the same time
that these  phenomena  take place, the external  swelling
flattens down.   Afterwards, the ossification of the perios-
teum disappears, the medullary canal  is reproduced, and
things are  restored to the  state in  which  they were
before the fracture.
  There is then in the reunion of fractures, as in wounds
of the soft parts, a  vascular cicatrix, formed nearly by
the same mechanism.   The whole difference  consists in
the changes which  the surrounding  parts  undergo, and
which give place to  the  development of a  provisional
bone, before  the final  callus is formed.  Strike out the
second  period, and the  mode of reunion of  fractured
bones will  not differ sensibly from that of the soft parts.
  It is thus seen what  should be  thought of the opinions
so various, which  authors have had  upon the formation
of callus.   Most are exclusive from having observed the
callus in one period of its  development only.   It is thus
that Duhamel, and  after him  Fougcroux and  Pelletan,
have seen  perfectly that the periosteum is ossified ; but
they attributed to it too much  in  supposing that  it was
this  which constituted the  callus.  Now this  will not
appear astonishing, when it is  known, that Duhamel did
not pursue his experiments upon  the  callus, otherwise so
praiseworthy, beyond  thirty or forty days.   So  Boer-
              20 
154              ADDITIONS TO THE
 haave,  Haller and Dethleef found between the fragments
 a lymphatic matter and were  satisfied with  this observa-
 tion.    Almost  in  our  days, Hunter,  Macdonald  and
 Howship have said that it is the effused blood, the colour-
 ing  matter of which  is absorbed,  which  is afterwards
 organized to  give birth  to the  callus.   Others from the
 example of Bordenave, have been deceived by what takes
 place when  the fracture is in eontact with the  air, and
 have thought that it was the  same  when the fragments
 were  not exposed ; Bichat himself did  not  avoid  this
 errour.   Some, such as Troja and Camper, have approach-
 ed nearer the truth, by adopting a mixed opinion.   But
 it is especially to modern anatomists that we are. indebted
 for  the knowledge of the facts  which we  have  stated.
 M.  Dupuytren was one of the first  who  observed  these
 facts.  We are indebted to Messrs. Breschet and Villerme
 for a very extensive work upon this  subject.
  There are fractures in which no bony callus is formed,
 but only  a fibrous  cicatrix which unites the  two frag-
 ments  loosely.   It is  what is seen  especially  in those
bones which, like the patella,  olecranon process and neck
 of the femur, are very difficult to be kept perfectlv fixed.
 The motions of the fragments  and their separation are in
fact the  sole causes of this phenomenon, which was  for-
merly considered as constant in these  bones and dependant
 on their structure, and* which it has been attempted to
 explain  by a pretended dilution  of the osseous juice, by
the  absence of periosteum, &c.  The same  result is obtain-
 ed,  when in a living  animal,  a portion of a long bone is
 cut  out; if the distance between the two ends be too great
for  their extremities  to unite by becoming thinner  and
 extending towards each other, the callus is in part fibrous
or fibro-cartiiaginous.  The opening made by a trephine
exhibits also this peculiarity ; when it  is very broad the 
OSSEOUS SYSTEM.
155
cicatrix is completed  by a fibrous portion.    On the con-
trary, the  reunion is immediate, even in bones which
were not thought capable  of it, when  the  approximation
of the fragments has been exact for a proper  time.   I
have  seen  patellas  thus  united ;  dried  and  soaked  in
spirits of turpentine  for  the purpose  of  rendering the
cicatrix transparent,  as it would have done if it  were
fibrous, they proved to be osseous in every part.  These
cases  are in truth  very  rare, because the separation  is
almost inevitable, as   it  may  come on not only at the
instant  of  the  fracture, but as long as the intermediate
substance has  any extensibility, the  callus itself may
sometimes yield,  and it requires  at  least two or  three
months for the  callus  to acquire complete solidity, instead
of from fifty to sixty days as is commonly thought.  This
termination of the fractures is precisely analogous to what
takes  place in the long bones, when their  fragments are
continually moved.   There results  from it a kind of false
articulation.
   The  bones are rarely  affected with organic diseases;
this point  of their history has been hitherto neglected.
Yet the cancer of the bones has been described under the
name of osteosarcoma ;  but much remains to be done to
classify all that has  been  designated  under this name.
Sometimes a tubercular affection  is met with in the bones.
They are also  the seat of a kind of fleshy  tumour, which
interrupts  entirely their  continuity, and  the texture  of
which is very  like that of the cerebriform  tumours, ex-
cept that it contains  more blood-vessels.   I have  many
times seen these tumours in the clavicle.

         III. Alterations in the Development.

   The  osseous system is subject  to frequent  defects  of
conformation ;  they are observed especially in  the bones
of the cranium  and in the sternum. 
ADDITIONS TO THE OSSEOUS SYSTEM.
   The osseous substance has a tendency to be produced
under  many circumstances.  There is scarcely any part
which  is not ossified by the progress of age.  The carti-
lages are in the first rank ; then come the fibro-cartilages
and  the  fibrous  textures  as it  respects the frequency of
this  ossification.  The cellular texture is the most rarely
the seat of it.  As  to the arteries, there is in many cases
a sort of incrustation, rather than  a real osseous trans-
formation.   The venous, muscular and nervous systems
exhibit more rarely examples of it.   The  preternatural
productions are  not exempt from  this transformation ;
cysts wholly osseous are often found.  The cartilaginous
state does not seem always to precede  these ossifications. 
ADDITIONS
TO THE
MEDULLARY SYSTEM.
      Organization of the Medullary Membrane.

   Page 231.—" To be convinced of its existence," (the
medullary membrane,) " expose the cylinder that it forms
to the intense  action of heat; it contracts, has the horny
hardening immediately like all the solids, and thus  be-
comes more apparent."

   This experiment is  made by sawing a long bone, and
then plunging it into boiling water ; the membrane sepa-
rates from the bone and adheres to the  fat, which ena-
bles  it to be better  seen.   The diluted  mineral acids
may also be used, which produce the same effect.
   This membrane when entirely detached from the bone,
resembles in some measure a cobweb;  it is pierced with 
158
ADDITIONS TO THE
a multitude of holes.  The basis of it is the cellular tex-
ture and vessels.   The first is in small quantity  and has
no  other use than to support the vascular ramifications.
Among these last, some which are very well described by
Duverney, go outwards to the osseous texture; the others
go inwards, towards the elongations  of this  texture  and
of the membrane itself.   The  principal  artery  of the
medullary  canal is surrounded by absorbent vessels at its
entrance into this canal.   An evident nervous plexus is
also observed  about it, in the bones which are the nearest
the trunk.
  Moreover,  adipose vesicles of the  same kind as those
of the cellular texture, though  they  may be a little less
distinct, contain the medulla and occupy the interior of
the  medullary membrane,  lodged  in the cellular inter-
stices which this last contains ;  we know not if they are
also found in  the  spongy  texture  of  the  extremities.
Authors have for a long time  noticed that  the  medulla
is formed of small grains united into a cluster, as is seen
especially  when it is recent and has not yet lost  the con-
sistence which is peculiar to it.   But it was believed that
these vesicles communicate with each  other, as it  was
then thought of the adipose texture.  G. Hunter,  Mas-
cagni and many others have seen that they are shut.   The
description which they have given  of them, both from
direct inspection and analogy, shows in  them an  arrange-
ment similar  to that of the adipose texture.  We shall
 not advert again to this arrangement.

        Sensibility of the Medullary Membrane.

   Page 231.—" The most acute  pains are the result of
 the action of the saw upon it"  (the medullary membrane)
 " in amputation." 
MEDULLARY SYSTEM.
159
   This phenomenon  is not constant; there is  often  no
pain in this case ;  but we must not conclude from it, as it
has been done, that the sensibility of the medullary mem-
brane  does not exist.  In  amputations  made upon man,
the pain caused  by the division  of  the soft parts,  and
especially of the skin, is so intense, that this less severe
one produced by the division of the medullary membrane,
which almost  immediately succeeds  it, is hardly felt.
But if, in a living animal, the operation is suspended after
the division of the soft parts, and resumed when the first
impression is in part  dissipated,  the  sensation is acutely
perceived,  and the animal  utters distressing cries.  The
sensibility of the marrow, already recognized by Duverney
and since denied, is then real.

                     Development.

   Page 234.—" This absence of the medullary fat in the
foetus, essentially distinguishes the marrow from the ordi-
nary fat, which, at this age, is already very abundant."

   The fat of the bones, in  being wanting  in the  foetus,
resembles in this respect that of the deep parts in general,
which are then almost entirely destitute of it.  Moreover,
there is  not only no  marrow  at this age, but there is
no medullary membrane.   Bichat did not wish to con-
sider this membrane as a new organ ; but it is evident that
nothing indicates its presence before  ossification.   After-
wards, when  the  medullary canal begins to  be formed,
the nourishing artery fills it entirely ; it is not till an after
period that this artery is thrown out upon the parietes of
the cavity and that the medullary membrane exists.
   The marrow becomes very abundant in old age, owing
to the enlargement of the medullary cavity. 
160               ADDITIONS TO THE
                      Functions.

  Page 236.—" Who does  not  know, that  in  diseases
of the articulations in which the synovia is altered and
vitiated, the marrow of the corresponding bones is almost
always in  a perfectly sound state."

  To the  reasons for not admitting the production of the
synovia b}' the transudation of the  marrow through the
articular extremities, may be added those which Soemme-
ring has given, viz. that the marrow is the most abundant
precisely in the place the most remote from the extremi-
ties, and that children, who have no marrow, and whose
extremities are all cartilaginous, have not less of synovia
in their articulations.  This last fluid is met with besides
in many places where the other evidently cannot  pene-
trate, as around the tendons, in the bursae mucosae, either
natural or preternatural; finally, there is a total difference
of properties and composition between  it and the medul-
lary fat.
  Various uses,  not less  hypothetical, have also  been
attributed to the marrow.  It has been thought to be well
adapted to give flexibility and tenacity to the bones ; this
was the  opinion of Duverney ;  but if it  be recollected
that the bones of young subjects  are the least susceptible
of breaking, and that those of old people, which contain
so much marrow, are on the contrary the least resisting,
much attention will not be  paid to this  opinion, which
rests only on  a  single fact; it  is this, that the bones,
reduced by combustion to their calcareous matter, resume
in part their solidity when boiled in  oil ;  but the  same
thing takes place with every other substance, with  gela-
tine for example, and there is a great difference between 
MEDULLARY SYSTEM.
161
a bone which combustion has destroyed in part, and that
which still contains all its principles.
  The ancients said that the  marrow served to nourish
the osseous texture ; but it is sufficient, that there are a
great number of bones destitute of medullary fat, to ren-
der  this inadmissible.   The medullary membrane per-
forms on the interior of the bone the office of periosteum ;
it contains  nourishing vessels, and it is in this way only
that it  contributes to nutrition.  As  to the marrow,  it
must have  the same  general uses  as the fat; it is a kind
of aliment  in  reserve,  one of  the forms  in which the
nutritive matter is clothed.  It  serves besides  to  fill the
void which without it would exist in the medullary canal.

     Morbid Anatomy of the Medullary System.

  The alterations of this system  have not been sufficiently
studied to enable us to present a complete  view of them.
We shall here confine ourselves to a mere sketch.
  It is very probable, as Bichat says,  that the medullary
membrane  of the long bones is affected in syphilitic pains.
In fact, a  slight percussion made on the  surface of the
bone excites these pains, on account of the jar  it commu-
nicates to the marrow.   Besides, we are completely igno-
rant what kind of alteration this last experiences.
  In amputations, the oily matter of the bones is absorbed
in the neighbourhood of the wound ; the medullary mem-
brane is covered with fleshy granulations, and contributes
to the formation of the  cicatrix.   What takes  place after
fractures has already been noticed ; a sort of hardened
plug fills  the medullary canal ; this canal  is  afterwards
reestablished, unless the union between the fragments be
not exact, as when they slide over each other.   In necro-
ses  which include the medullary canal, when the old bone
             21 
 1G2   ADDITIONS TO THE MEDULLARY SYSTEM.

 has been drawn out, there remains a  reddish membrane
 which lines the new one ; but the marrow is not repro-
 duced.
   Spina ventosa is an affection peculiar to the  marrow ;
 it is a true cancer of the  medullary membrane, different
 from the cancer of the bone  and from that which affects
 the  periosteum, but analogous  to these affections  in  its
 nature.  The disease has its seat usually near the extrem-
 ities ;  on the leg, it is towards the superior end, and  on
 the  thigh, it is towards the inferior,  that it most often
 exists.  It may happen that  the osseous texture is at the
 same time  altered ; but frequently this texture  is sound
 and  has only experienced  a  greater or less dilatation, a
 simple extension.   It is then found that the bone forms a
 covering to the tumour,  sometimes enormously dilated,
 often perforated and traversed by vegetations of a cancer-
 ous nature  ; this is what I have many  times had occasion
 to observe.
   The medullary fat varies much in quantity according
 to the state of corpulency ;  but the  medullary canal is
 always full of a fluid which resembles the marrow more
 or less.  In fat subjects, the marrow has appeared to me
 to contain, in eight parts, seven of oily and one of foreign
matter.  This agrees with what has been stated  by Gru-
tozmacher.  In a  phthisical  subject, I have seen the fat
form only a quarter ; the rest was a serous or albuminous
fluid similar to that of  which  Bichat  speaks.  It would
then be possible, that in extreme emaciation, there might
be hardly any fatty matter. 
ADDITIONS
TO THE
CARTILAGINOUS SYSTEM.
                 Peculiar  Texture.

  Page 243.—" With a little attention we distinguish"
(in this texture) " longitudinal fibres, which  are crossed
by transverse and oblique ones."

  It is very difficult to see these fibres distinctly; every
thing appears to be homogeneous in a cartilage cut through,
as Bichat observes.   The only thing which denotes organ-
ization in it is, that  an oozing of serum takes place, at the
end  of a short time, upon  the divided surfaces, which
indicates that there  were fluids in circulation in it.   This
oozing is more  abundant as the subject is younger.
  Various facts seem to show  that there is a  peculiar ar-
rangement  in  the cartilaginous  texture; on  this subject 
164
ADDITIONS TO THE
there are  different opinions.   Duhamel thought that this
texture was composed, in the cartilages of ossification, of
concentric laminae  superadded to each  other, from the
formation  of  the successive osseous  layers  which his
experiments  with  madder  had  demonstrated  to  him.
These experiments have been noticed elsewhere ; we have
seen what must  be  concluded from  them in relation to
the growth of the bones.  They in no wise prove the
arrangement of which we are treating, since the layers
are only formed on the surface of the  bone, when this is
once  completely  developed ; we  find  neither plates nor
layers of any kind in the pre-existing  cartilage.
  Flunter and Delassone  say that the  fibres of the carti-
lages  of the moveable articulations are perpendicular for
the most part, and implanted in the bones of these articu-
lations ; they compare the appearance which  results  from
it  to  the  texture of velvet.  The greater facility  with
which these  cartilages break in  the  direction of  their
thickness, the perpendicular direction of the fibres which
is seen in  them  when they  are cut in  this direction, and
maceration, which, if sufficiently long  continued, renders
these  fibres distinct, are, it is  said, the reasons upon which
this opinion is founded, which cannot be entirely rejected ;
for the structure which has just been described  becomes
sometimes  apparent  in  diseases.  I  shall say only in
regard to  the second fact,  that  the  traces,  which the
instrument employed to make the section of the cartilage
leaves, have no doubt been taken for fibres.
   According to Herissant, the cartilages  of  the  ribs are
formed of laminae twisted into a spiral form, and it is to
this arrangement that they owe their elasticity.   This
author cites maceration  as a proof of  what he advances.
His observations on this subject require confirmation. 
CARTILAGINOUS SYSTEM.
165
   Finally, some appear  to  have been  deceived  by the
changes which  the  cartilages undergo when they are on
the point of  being ossified.   It is thus that Mascagni
admits in  the  costal cartilages laminae in  the form of rays,
because he has  found in  the centre of  these cartilages a
sort of marrow  separating these  laminae.  But they exist
only in adults and in cartilages which have been exposed
to desiccation ;  now, the cartilaginous texture, taken at
this period,  is  not  perfectly homogeneous ; its exterior,
more compact, dries quicker than the interior, and cannot
contract, when this still tends to  diminish in size;  there
results from this, spaces which are produced in the centre.
We ought also to attribute to the  commencement of ossifi-
cation,  owing to the progress of age,  the  reddish and
areolar cavities which Morgagni and Portal have described
as inherent in the structure of the cartilages.
   The membranous cartilages of the nose and the ear,
which will be  noticed under the fibro-cartilaginous  system,
have, according to Soemmering, distinct little fibres, when
they have been  macerated a month.

                Chemical Composition.

   Page 244.—" Ebullition upon the articular extremi-
ties, breaks it,"  (the cartilaginous texture,)  " and raises
it by layers which it softens, and which finally it  melts
almost completely."

   The cartilages of  the sutures are likewise dissolved in
boiling water  and furnish a sort of jelly,  like the diarthro-
dial cartilages; all the others resist ebullition, and do not
give out gelatine in this case unless they contain  osseous
points.  This  accords with what  is known at the  present
day of the composition of the cartilages.  Haller thought 
166
ADDITIONS TO THE
 that they were  formed of water, gelatine, and an earthy
 substance ;  but  modern chemists have  obtained different
 results.   Mr. Hatchett  has  found in the cartilages albu-
 men and  the phosphate of lime.  M. Chevreul has given
 the analysis of the cartilaginous  bones of the  Squalus
 Maximus;  they  contain, according to  his  researches,
 mucus, oil,  acetic acid and various  salts.  Finally, accord-
 ing to J. Davy,  there is in the cartilages 44,5 of albumen,
 55,0 of water, and 0,5 of the phosphate of lime.
   Moreover, this composition  must  vary at the different
periods of life, as well as the proportion of the constituent
principles.  The cartilages of young subjects contain more
fluids, as may easily be proved by  drying them compara-
tively with  those of an adult.  They are reduced almost
to nothing  in  this  experiment,  whilst the second  lose
much less of their size.   We see besides in combustion,
that there is scarcely  any ashes left of the first, whilst
the others give an abundant earthy residue.
   MORBID ANATOMY OF THE CARTILAGINOUS SYSTEM.

       I.  Alterations in the External Forms.

   The articular cartilages are sometimes swelled and soft-
ened in white swellings, at other times detached  in part,
hanging  in  the  articulation, and  often destroyed  to  a
greater or less extent; this destruction, frequent in the
diseases of the articulations, may bring on anchylosis.  In
some cases the articular cartilages seem to have entirely
disappeared,  and  there are  only found osseous surfaces
like  ivory ; is  the cartilaginous  texture ossified  in this
case  as Bichat  says, or has  it been destroyed ?  It is diffi- 
CARTILAGINOUS SYSTEM.
167
cult to determine  this.   These same  cartilages  exhibit
frequently after rheumatic affections and in consequence
of chronic engorgements,  species of floating fibres, loose
at their extremity ; it is these fibres which seem to favour
the opinion of Hunter and Delassone upon the structure
of the cartilages.   The cartilaginous texture seems to be
decomposed in this case, unless this alteration be regarded
as the result of a partial  erosion.

          II. Alterations in  the Organization.

   Inflammation has never been observed in the cartilages;
in no case  are the vessels of these  parts coloured  with
blood ; white fluids alone appear to be capable of accumu-
lating in them.   Ulceration  however,  which  does  not
spare the articular cartilages, as we have just seen, is a
proof that inflammation may  be developed in them.
   Denudation  and  wounds, which everywhere else are
followed  by inflammation, do not produce this effect in
the cartilages.   When they are laid  bare  in a wound of
the soft parts,  this reunites by  adhesion or by cicatriza-
tion,  according as the flap has been reapplied or  not;
but the cartilaginous texture  does not participate in the
work of reunion, as J. Hunter and J. Bell have seen ;  it
remains  insulated,  covered  by the  cicatrix, without in
any way adhering to  it.  When an articulation is  opened
in a living animal, the cartilage  does  not inflame nor red-
den, whatever  may be the duration of its exposure to the
contact of the air ;  only if the experiment is prolonged,
we see the synovial  membrane, red at first in the other
part of it, inflame also over the  cartilage, and the redness
of this membrane extends gradually towards the centre
of the cartilage. Yet broken  cartilages reunite, as  Auten-
rieth  first discovered  in the costal cartilages.   Different 
168
ADDITIONS TO THE
observers, Messrs. Magendie, Lobstein  and myself have
recently confirmed  this fact.  But the part of the carti-
lages is purely passive in this case.  When those of the
ribs  are fractured,  if the two  ends remain opposite,  an
osseous band  is formed around  them and  keeps them in
contact; if, as is most common, the  fragments have slid
upon each other, a band, at first fibrous, then cartilaginous
and osseous, holding to the perichondrium,  fills the space
between them ; but in this case, as in the other, they are
merely contiguous.   It is only in old age, when the car-
tilages are upon the point of  ossifying,  that they reunite,
like  the bones, by a true intermediate callus.
  Ulcers of the  diarthrodial  cartilages are sometimes the
seat of a process of separation which resembles, to  a cer-
tain extent, that of the wounds of the soft parts.  There
is then  found cartilaginous portions newly formed in the
place of those which the erosion had  destroyed.   This
affection has been taken by some for an original defect of
conformation ; it is evidently only secondary.
  The osseous transformation is the  only  one which the
cartilages experience ;  but  they experience  it almost
necessarily with age,  and almost without departing  from
the natural order.  Besides, we distinguish,  in  this re-
spect,  two kinds of cartilages ;  one,  merely  temporary,
becomes ossified in the first year ; the other,  which con-
tinues  a longer  time, is  called  permanent, but  only in
relation to the first,  for the cartilages of  this kind also
finally  become ossified ;  the cartilages of  the moveable
articulations are perhaps the only exception.   But their
ossification does  not take place regularly nor  at  fixed
periods, like that of the temporary cartilages ; it may be
delayed to a very advanced age.  Keil has  seen the costal
cartilages not ossified in  a man of a hundred and  thirty
years;  Harvey has  made  the   same  observation   upon 
CARTILAGINOUS SYSTEM.
169
another of a hundred and fifty-two.  Besides, the mecha-
nism of ossification is the same for all the cartilages.

         III. Alterations in the Development.

  The cartilaginous system is  subject to a small number
of defects  of conformation ; the costal  cartilages  some-
times exhibit these irregularities.
  The  preternatural development  of this  system  has
already been noticed ;  we shall advert, in the synovial
system, to the  foreign bodies of the articulations and to
the true mechanism of their formation.  The cartilaginous
productions differ,  like  all the others, according as they
appear  to be deposited, as  it were, in  the interstices of
the organs, or as  they are owing  to  a transformation,
which  one  of  them has undergone.   Insulated cartila-
ginous  masses  have been found  in various parts.   More
often  still various organs become cartilaginous.  M.  Laen-
nec has met with  this  transformation in the urethra ; I
have observed  it in the vagina, in consequence of  inver-
sion of the womb ;  I have also seen it in the prepuce, in
a case of phymosis.
22 
 
ADDITIONS
TO THE
FIBROUS SYSTEM
               Yellow Fibrous  Texture.

  Page 269.—" They appear" (the ligaments placed be-
tween the laminae of the vertebrae) " to contain much less
gelatine, and to be entirely different in their nature."

  These ligaments  belong,  in fact, to a division of the
fibrous system, confounded for a long time with the other
organs of the same name, but which differs  from them in
a great number of characters ; I shall now speak of the
yellow  or  elastic  texture.  It will  be  necessary  then
henceforth  to  divide the  fibrous system into two great
classes ; one will comprehend the white fibrous organs or
albugineous one of M. Chaussier, the other the yellow
or elastic  ones.  The last expression  is perhaps better
adapted than the first to designate this kind of texture, as
its elasticity is its  principal character,  whilst the colour 
172               ADDITIONS TO THE
is not as essential to it.   Besides, no one that I know of,
has given a complete description of this texture ;  it has
hitherto only been  noticed in unpublished lectutres.  M.
Chevreul, it is said, is engaged in  examining its compo-
sition.
-  This  texture is met with  wherever a resistance is re-
quired to be  continually in action, a sort of perpetual
antagonism, differing in this respect from  the ordinary
fibrous texture, whose resistance is, as it were,  passive,
and  which is  only brought into exercise by distension,
and from the muscular, which  only resists  as  long as its
contraction continues.  It is found  in  animals under the
same circumstances.  The  posterior cervical  ligament of
quadrupeds acts so as to oppose the weight, which inces-
santly tends to bend the head.  A covering of the same
nature strengthens the abdominal  parietes in the same
animals, and prevents them from yielding to the  weight
of the viscera.   The  whole genus felis has  an elastic
ligament inserted in the claw, keeping  it extended, when
the animal no  longer contracts its  muscles to render it
prominent.  The shells of the bivalves, oysters, muscles,
&c. are  opened by means of an analogous fibrous texture,
when the muscles which shut them are relaxed.  In man,
besides  the yellow ligaments of the vertebrae,  we should
also  enumerate among the organs which this texture con-
tributes to form,  the peculiar membrane of the  arteries,
veins, lymphatic vessels,  excretory ducts, air tubes, the
fibrous  covering of the corpus cavernosum, the  urethra,
and  perhaps also that of the spleen.  All  these parts
require  an incessantly active force, opposed  to  distension,
which makes them contract as soon as the contrary effort
ceases to have the ascendancy.
   The fibres of the elastic texture have the  same arrange-
ment as those of the white fibrous texture.  Their colour 
FIBROUS SYSTEM.
173
borders more or less  upon  yellow; it  is more evident
in the  dead body.  Their tenacity  is  less  than that of
the other texture ; their elasticity,  on  the  contrary, is
greater.   The vessels of this texture are few.
   Stewing does not resolve it into gelatine, like the white
fibrous texture.   It appears to contain much fibrin, joined
to a  little gelatine and albumen.
   Its properties are slightly  marked,  except elasticity
and  resistance, which  especially characterize it.  It does
not appear to be sensible, or at least it is not so, like  the
fibrous system  in general, except to  certain kinds of im-
pressions.   It  is  rarely  ossified.   Its  functions are  to
serve as a connexion or covering, and to perform at  the
same time the  office of a  spring, which obeys extension
and contracts quickly  when  the  extension  ceases.  This
is  what is very evident in  the  arteries ; the column of
blood which they contain, moved at each contraction of
the ventricles, stretches the  parietes  of  these canals;  but
the instant after, elasticity contracts these parietes ; hence
the course of the blood  is continuous, whereas  it would
be interrupted if the heart was the only agent of impulse,
as we have said elsewhere.
      MORBID ANATOMY OF  THE  FIBROUS SYSTEM.

        I.  Alterations in the External Forms.

  The ligaments and tendons  become  thick and  soft in
white  swellings ;   they are then brittle, if we may so
say, and yield to the least efforts made  upon them.  The 
174
ADDITIONS TO THE
surrounding  cellular  texture  is  often  confounded with.
them and  with that  of the  neighbouring parts,  which
takes from them their mobility, and explains in  part the
immobility of their  situation  and the embarrassment of
the motions which almost always accompanies these dis-
eases.  In  other cases, as in  some contractions, the mo-
tions are prevented by the rigidity which the tendons
acquire, and by the difficulty with which they are stretch-
ed.  The ligaments have a similar  rigidity in false an-
chylosis.

        II. Alterations in the Organization.

   Inflammation of the  fibrous parts is but little known.
That of the periosteum is the most common ;  it performs
a very great part in  many of the diseases of the bones.
I have seen several tendons the seat of slow engorgement,
which had  sometimes been evidently the consequence  of
an acute inflammation, such as that produced by a punc-
ture, for  example.   I  have myself  had an  affection  of
this  kind  which was  produced by  a puncture on the
hand ; a tumour formed in the extensor tendon  of a
finger  and  continued a very long time.
   It is particularly in ruptures of the tendo Achillis that
we have occasion to observe  the  mode  of reunion  of
the fibrous organs when divided.  A  coagulable matter
of the nature of albumen or fibrin  is then poured out,
which  gradually increases  in density,  till  it  finally
unites  with solidity the two  ends ;  this  substance, soft
and extensible in the beginning, is capable of being elon-
gated at this period, as happens in fact when  the limb  is
too much moved.  The rupture of the ligaments almost
always takes  place in  luxations ; but  what takes place
after the reduction of these last has not been  described. 
FIBROUS SYSTEM.
175
   Ossification is rare in the fibrous texture.  The kind
of hardening which  this texture  undergoes in old age
hardly ever extends so as to produce this transformation ;
it scarcely ever takes place except in  the tendons, at the
places where there is  friction, and in the  ligaments, at
their extremity attached to  the bones.   It is not the same
in some animals ; in  the gallinaceous ones, for example,
the  tendons  of the muscles of the  feet are  uniformly
osseous at a certain period.
   The periosteum  is  sometimes affected with  cancer, as
is seen in  what some call  the fungus or medullary
fungus of  the periosteum, others  the bony tumour,
lymphatic   tumour of the periosteum,  &c.   Other
fibrous  organs, as  the dura mater, exhibit analogous tu-
mours.   Periostosis differs  from these tumours in this,
that it  is the effect  of an  exudation which takes  place
below the periosteum detached from the bone ; the matter
of this  exudation  becomes sometimes  more  and  more
consistent; we have  seen  that it may become osseous.

          III. Alterations in the Development.

   Certain defects of conformation  are accompanied with
an extreme relaxation of the ligaments which  unite the
bones, of which club-feet furnish an example ; the relaxa-
tion in  this case is  but  a secondary circumstance, which
is owing to the weakness of some of the muscles.
   The  fibrous texture  is produced under  many  circum-
stances.   1st. Without speaking of  its  reproduction
when it is divided itself, the cicatrices of various  organs
are  essentially fibrous ; this is what we  have  already
seen under  some  circumstances in the bones, and what
we shall see hereafter in the muscles and the  skin.  2d.
The cellular texture,  the retina, the substance of the tes- 
176
ADDITIONS TO THE
tide and the thyroid gland are  sometimes changed into
the fibrous texture.   3d.  Various fibrous productions are
developed in the substance of the organs.   They assume
the form of membranes, as in cysts, fasciculi, as  in  the
ligaments of the false articulations, or they are  masses
known  by the  name of fibrous bodies.  These  bodies
are especially met with in  the uterus ; Bichat  mentions
them.   They occupy different points of the substance of
this organ.  Their number varies ;  many are often found.
At first very small, they gradually increase in size, and
become in some cases considerably large.  Their fibres
form  layers nearly concentric, and appear as  if wound
like balls ; they receive  vessels more or  less apparent.
These bodies often  pass  to the fibro-cartilaginous  state;
but this state is  not peculiar  to  them, as has been  said.
Ossification even may seize upon them ;  they then resem-
ble stones or concretions.  Sometimes they are entirely
detached and fall off, either into the cavity of the perios-
teum,  or into  that of the uterus ; they  form,  in  the
second case, the pretended  calculi of the womb, of which
many examples are found in a memoir by Louis inserted
among  those of the Academy of Surgery.  The  fibrous
bodies of the  uterus have  been known for a very long
time ;  Chambon gave them the name of scleroma.   But
it is especially to Bichat, whose ideas  upon this  subject
have  been published by M. Roux, and  to  Bayle,  that
we are indebted for a more accurate description.  Analo-
gous fibrous bodies have been found in other parts, as in
the neck and in the  substance of the fingers.   It is not
unusual to find around the  vagina, between the bladder
and this canal, between the latter  and the  rectum, or in
its parietes even fibrous  tumours, which, in truth, differ
a little  from the preceding.   They have not  the  knotty
appearance of  these last; their texture, soft and flexible, 
FIBROUS SYSTEM.
177
has some resemblance  to that of ordinary  polypi.  But
they do not arise like them;  their adhesion  to the neigh-
bouring textures is slight, so  that their  extirpation is not
difficult.   M. Pelletan  cites  examples  of this affection ;
M. Dubois  has observed it a great number of times ;  I
have myself seen many of these tumours.  Their structure
deserves to be  examined thoroughly.  It is important to
know them in practice,  because if care be not taken, mis-
takes on this subject may be committed.
23 
 
ADDITIONS
TO THE
FIBROCARTILAGINOUS SYSTEM.
 Of the Nature of the Membranous Fibro-Cartilages.

  Page 316.—" It is  not  only in its form, but also in
its nature, that  this class"  (viz. that of the membranous
fibro-cartilages) " differs from the others as we shall see."

  This nature is perfectly analogous to that of the carti-
lages, which the membranous fibro-cartilages resemble in
all their characters,  as may be  easily seen by comparing,
in the history of the fibro-cartilaginous system, their pro-
perties with those of the other bodies which are classed
under it.  Thus Meckel in  his  General Anatomy, observ-
ing entirely the distinction established by Bichat, between
this system and  the cartilaginous, places these organs in
the latter  under the name  of  membranous cartilages. 
180
ADDITIONS TO THE
I am entirely of his opinion.  In fact, 1st, like the carti-
lages, and the pretended membranous fibro-cartilages they
seem to  be homogeneous in  their structure, and have no
evident fibres.  Those which cover this surface belong to
the perichondrium, which is  very thick upon these carti-
lages ;  when  stripped  of this membrane, they  have the
appearance of the  cartilaginous texture.    2d.   Gelatine
cannot be extracted from them by ebullition, as from the
other fibro-cartilages.  They are on  the contrary in  this
respect like most of the  cartilaginous textures.   Desicca-
tion also acts upon  them nearly as upon  these last.   3d.
Most of the  fibro-cartilages  are destitute  of perichon-
drium ; these have  it  very distinct, as I  have just said.
It is to the fibrous  texture which covers them that these
cartilages owe their suppleness,  the only  property which
they have in  common with the fibro-cartilages.


   Of the forms of the Fibro-Cartilaginous System.

   Page  316.—" These three classes of fibro-cartilages,"
(the membranous,  articular  and those of the tendinous
sheaths,) " though  very  analogous, have  not exactly the
same structure, the same vital  properties,  nor the same
life, &c."

   If the first class  be  rejected,  in conformity with what
has been said above, there will remain the articular fibro-
cartilages and those of the sheaths  of the tendons, which
are in fact  very  different from each  other.   These differ-
ences appear  to have their source principally in the differ-
ent proportions  in  which the fibrous  and  cartilaginous
textures are  in this system ; whence results a more or
less perfect resemblance  to one or the other of these tex- 
FIBROCARTILAGINOUS SYSTEM.
181
tures, a more or less evident  fibrous structure, resistance
and flexibility, or, on the contrary, more or less elasticity
and homogeneousness.   The following table may be made
of the fibro-cartilaginous system, by adding to the forms
pointed out by Bichat, that of the rings of this nature in
which the superior extremity of the radius and  the ten-
don  of the great oblique muscle of  the eye slide, and of
the  bands, also  fibro-cartilaginous,  which  increase  the
depth of certain articular cavities.
w
<

pi
<
O
6
Pi
 ARTICULAR.
  They are in re-
lation with the ar-
ticular surfaces of
the bones, and per-
form various uses
towards  them.
  Those of the di-
arthrodial articula-
tions are embrac-
ed by the synovial
membrane of these
articulations.
 They may be di-
vided into
   OF Sf.IDIWG.
  Their name in-
dicates their use ;
almost all are con-
nected  with  the
tendons.
  They are
«{  Adherent
'Free ; example, that of the lower jaw.

            '   By their  extremities, as that
             of the clavicle, of the inferior
             extremity of the ulna, those of
             the  knee, &c.           '
               By one of their surfaces, as
           j the  bands which are attached
  These are^ to the edge of the g]enojd? and
            I cotyloid cavities.
               By their  two surfaces ; such
            | are   the  inter-vertebral  sub-
            | stances, those  of the pubis, sac-
            l.rum, ice.
   Flat; those of  the tendinous sheaths  or of
 covering.

   Circular ; the pulley of the great oblique
 muscle of the eye, and the  annular ligament
 of the radius;  this serves besides to close the
 articulation of this bone. 
182
ADDITIONS TO THE
MiORBID ANATOMY OF THE FIBRO-CARTILAGINOUS SYSTEM.

        I.  Alterations in the External Forms.

  The inter-vertebral substances are sometimes found in
diseases remarkably swollen, softened and  engorged with
fluids ; which produces a greater mobility and less solidi-
ty in the vertebral  column.  The symphysis  pubis still
more evidently undergoes this alteration in pregnancy.

         II.  Alterations in the Organization.

  The organic affections of  the  fibro-cartilages are  but
little known.  Yet ulcerations have been  seen  in them;
Messrs. Palletta and Brodie have  described a  variety of
vertebral diseases which commence by the  erosion of
the inter-vertebral fibro-cartilages.
  The manner in which these organs are repaired  when
they are divided, has not been ascertained.  It might be
easily seen, for example, after the operation of  the  divi-
sion of the symphysis pubis.
  As to the ossification of  the fibro-cartilages,   a distinc-
tion may be established  here, as in  the cartilaginous sys-
tem, founded  upon the period at  which this ossification
takes place.   There  are in  fact,  temporary fibro-carti-
lages which serve as moulds for the bones, as there are
cartilages of  this name ;  these are regularly ossified, and
this transformation is for them only a consequence of their
natural  development.   These fibro-cartilages of ossifica-
tion are met with  where  bones are developed in  the
fibrous textures,  as  is seen in the article  on the osseous 
            FIBRO-CARTILAGINOUS SYSTEM.         183

system, with regard to the sesamoid bones; the osseous
points of  the  stylo-hyoidean  and thyro-hyoidean  liga-
ments are also formed in this  manner.  On the contrary,
the permanent fibro-cartilages rarely pass into the osseous
state.  This  sometimes happens as  has been  said, with
regard to those of the vertebrae ;  yet oftentimes in  these
cases, the external layers alone are invaded.  At the
pubis, this phenomenon is  extremely rare ;  it is a little
less so in the sacro-iliac symphysis and in the  sacral  ar-
ticulations.  The fibro-cartilaginous organs seem to  be, in
this respect, intermediate to the cartilaginous and fibrous
textures, as they are so in many others, they are ossified
less  often  than  the first,  but more frequently than the
second.

          III. Alterations in the  Development.

   There are preternatural fibro-cartilages, 1st, in the cure
of some fractures  badly  kept in  place;  2d, in  false ar-
ticulations, in consequence of which the periosteum often
takes this form; 3d, in alse anchyloses, which are some-
times produced by filaments of the  same  nature ;  4th,
finally, in cysts, in tumours of the uterus, the thyroid
gland, &c. and  in  which  are  often found  some fibrous,
fibro-cartilaginous parts, &c. 
 
ADDITIONS
TO THE
MUSCULAR SYSTEM OF ANIMAL LIFE.
          Intimate Structure of the Muscles.

  Page  335.—" I  would  compare the anatomical re-
searches upon the intimate structure of the organs, to the
physiological researches upon  the first causes of the func-
tions.  In  both we are  without guides, without  precise
and accurate data; why then give ourselves up to them?"

  Notwithstanding the little apparent utility which these
researches seem to have, since many learned men are  still
engaged in them, I thought it might be satisfactory to  find
here a short analysis of the labours and opinions of which
the muscular fibre has been the object.
  Some  consider it divisible  almost ad  infinitum ; Muys
says that each fasciculus must be divided and subdivided
eight times before we can arrive at the ultimate muscular
             24 
186
ADDITIONS TO THE
fibre ; others,  Prochaska  for example, think that these
divisions are much too numerous.  There  is the same
difference of opinion  as to  the  size of this  fibre.  It is
less, according to most authors, than the globules of the
blood.   Sprengel, who has measured it by the micrometer
of Banks, attributes to it, on the  contrary, a much greater
diameter, which he considers to be equal to the fortieth
of a line in the mammalia, and to the twentieth in birds
and  fishes.
   The  muscular fibre appears to be  unequal and as  it
were wrinkled on its  surface, which has been  variously
explained.   It  has  been said that these inequalities were
the  mere effect of  muscular contraction ; that they were
owing to the  contractility of texture of  the cellular and
vascular parts  which surround the fibre; that it is a con-
sequence of the knots and contractions, of which this  is
composed.   This  last opinion is best  founded in insects,
which  exhibit evidently  in their  fibres  this  kind  of
knotty appearance; but it is not by  any means, so  evi-
dent in  man.  Meckel, who has  seen this  arrangement
very clearly in the first by  the  microscope,  has not been
able to  detect  it in the second.   The muscular fibre has
appeared to him in man, to  be nearly uniform  and of the
same size in all its points ; only there is always observed
in it globules or opake points, separated by a more trans-
parent  medium; which is very different from the knots
Home  has also observed  globules in the muscular fibre.
By  examining this fibre, deprived of its cellular texture
by  ebullition,  as  it should  always be  when we would
study it by itself,  and by maceration, he  has  seen it re-
duced to round particles precisely similar to the globules
of the blood.
   Various  observers have examined  with the  microscope
 the transverse section of a muscle.   The surface of this 
         MUSCULAR SYSTEM OF ANIMAL LIFE.      187

section  resembles very much that of basaltic earth ; the
fibres are compact,  flattened, and prismatic rather than
cylindrical.   A very good idea of them may  be  formed
from a plate which Prochaska has given.
   Is the muscular fibre solid or hollow ? This is  a ques-
tion with which  anatomists  have been  much engaged,
though it is  hardly  possible to  answer it by  inspection.
Thus there  has been  scarcely any thing  but suppositions
formed on this subject.  However, Lecat, Verheyen and
Vieussens  are all agreed upon  this point, and have  be-
lieved that it might be concluded from their observations
that each fibre of a muscle was an assemblage of vessels
of a particular order, continuous with the arteries and the
veins at the place where these  two orders of  vessels are
confounded,  but placed out of the  circulation of the latter.
These vessels, which might be  called  vessels  of deriva-
tion, are admitted  by Mascagni;  they are the same that
Bleuland says he  has found in  the  capillary system in
general, and in other parts as well as the muscles.  Hal-
ler, on the Other  hand, rejects  this opinion.   All those,
who like him,  divide the parts into those that are capable
of bein0, injected  and those that  are not, and this is the
case with the  greatest number  of anatomists, think that
the  muscular fibre is  solid and beyond the circulation of
the  fluids.

   Influence of the Nerves upon Muscular Irritability.

   Pa°-e 384.—" The duration of this last property," (sen-
sible organic contractility,)  " after the  experiment I men-
tioned," (the division of the nerves,) " proves completely
that the  nerves are  wholly foreign to it, that it resides
essentially in  the muscular  texture,   that it  is,  as Hal-
ler said, inherent in  it.  Thus whilst in  the different 
188
ADDITIONS TO THE
paralyses the muscles  lose  the power of  obeying the
cerebral influence, or rather this influence becomes nothing,
they preserve that of contracting  in an evident manner
when stimulated."

  When all the nerves of a muscle are cut, the  muscle
preserves only for a time the faculty of obeying the action
of stimuli; the  contractility is soon  exhausted and does
not reappear.  On the contrary, when  the  communica-
tion with  the nervous  centres is  free, the  irritability
diminishes also in proportion as it is put in exercise, and
finally,  as in  the  preceding case, disappears entirely ;
but if the animal  is suffered  to  rest, it  is reproduced.
Hence it would seem, that  this property is not inherent
in the muscle, but that it is entirely subjected to the ner-
vous influence.  The duration, besides  being shorter,  of
the irritability after the division  of the  nerves may very
well depend upon the influence of these  nerves below the
division ; an  influence which can  continue but  a little
time, not being renewed, from the want  of communica-
tion with the nervous centres.  According to  this idea,
which is that of Platner,  Legallois, &c.  the muscles
only put in action a  principle  which is brought to  them
by  the nerves, and these perform  a double part in the
contractility  of the muscular  texture;  1st,  they keep
this texture in a state of constant excitability for the sen-
sible organic  contractility ; 2d, they transmit  the excite-
ment under certain circumstances, as it respects the will,
for the  animal contractility.  The  muscles  are  to the
nervous system what the senses are to this system, parts
whose action  is intimately connected with its own, and
becomes nothing without it.  And  in fact this action,  in
the first as  in the second, is exhausted, lost and  repro-
duced  nearly  in the same manner.  Sleep, rest and food 
                       MUSCULAR SYSTEM OF ANIMAL LIFE.      \gi)

              reestablish the muscular energy when  weakened by long
              exercise, as they restore energy to the senses when theirs
              lias been destroyed by the same  cause.  We  have just
              seen  that this  does not appear to  apply solely  to animal
>              contractility, but  also to sensible organic  contractility,
              or irritability properly so called.
                However, all  physiologists are far  from being agreed
              in the  above opinion.  A great number have followed
              the  opinion of  Haller, and  attributed  to the nerves, no
              other use in contractility, than  that  of conducting the
              stimulus when it comes from the brain.  They rely upon
              this,  1st, that  Tourdes has ascertained that there  is mo-
              tion  in pure fibrin ? 2d, that vegetables and  zoophytes
              contract, though they are evidently destitute of nerves ;
              and 3d, that contractility is put into action in the muscles
              by stimuli which are  directly applied to them.   But, 1st,
              in admitting the  experiment of  Tourdes, which no one
              since has confirmed, its results are very different from
              those of muscular contractility ;  2d, vegetables and ani-
              mals without nerves are also without  muscles, thus their
              contraction has  nothing in common with the latter ; 3d,
              the last argument is in part  ccmbatted  by all the reasons
              alleged  above in favour of  the opposite opinion.  It  is
              very difficult, however,  to  resolve the question in an
              absolute manner.   We find  in  Meckel a sort of mixed
              opinion, which is perhaps the most accurate.   According
              to this author, the nervous influence is one of the condi-
              tions necessary to contraction, but it  only  operates  like
              the blood which the arteries bring, being like it indispen-
              sable to the life  of the muscle, which  does  notwithstand-
              ing possess its irritability of  itself. 
190
ADDITIONS TO THE
        Quickness of the Muscular Contractions.

   Page  395.—" When it is the will  that regulates  the
 quickness of the muscular  contractions,  this  quickness
 has infinitely various degrees ; but there is always one
 beyond which we cannot go."

    This quickness is in general very  great; it becomes
 sensible especially in the action of playing upon different
 instruments; it is found by estimating how many differ-
 ent movements each  note of  music requires that there is,
 in general, a contraction every sixtieth of  a second.  Dr.
 Wollaston has obtained the  same  result in another man-
 ner.   His researches  are given in a Croonian Lecture pub-
 lished in  the  Philosophical  Transactions for  the  year
 1810.   The  following  is the means  he adopted to  mea-
 sure the quickness of the  contractions.
   According to his researches, muscular contraction,  how-
 ever short may be its duration, is, as it were,  intermit-
 tent, and  composed  of many alternate small  contractions
 and  relaxations; the  kind of buzzing  which is heard in
 the ear when its aperture is closed by the extremity of
 the finger, is a  proof of it.  This peculiar noise  is owing,
 according to Dr.  Wollaston, to the muscular effort which
 the attitude requires; and in fact I have proved that it is
 nothing when the finger is replaced by an inanimate body.
 Now,  this buzzing includes a series of oscillations  very
 near together which  correspond  to so many contractions
 of the  muscles; it was only necessary then to  find a term
of comparison  for these oscillations, this Dr. Wollaston
 has done.   He  has compared this noise  to that which the
motion of a carriage produces, which is also intermittent, 
         MUSCULAR SYSTEM OF ANIMAL LIFE.      191

and the frequency of which it is easy  to estimate.  He
has ascertained the quickness stated above.

          Size of the Muscles in Contraction.

   Page  398.—" Their  volume" ( that of the  muscles
which contract) " remains about the  same.   What they
lose in length they nearly gain in thickness.   Is the pro-
portion very exact? Of  what consequence to us is this
insulated question, to which,  since the days of Glisson,
so much importance has been attached ! it deserves none."

   There are moreover  many causes  of error in the ex'-
periments which have been made on this subject.  Swam-
merdam, for example, says that by placing  the heart of a
frog in water the fluid  is seen to sink  at the moment of
contraction  and to  rise  in the relaxation ;  but the heart
containing a fluid which can increase or diminish the size
of it, without any change in  the texture of it, it is evi-
dent that nothing can be concluded from this experiment.
So in that of Glisson, who immersed the arm of a man in
a tub, and afterwards observed the difference of the level
according to the state of contraction or relaxation of the
muscles, the results cannot inspire great confidence, be-
cause on the one hand, it is quite difficult  in this case to
ascertain  precisely the level,  and because on the  other,
the contraction of the muscles being always accompanied
by the relaxation of the opposite muscles, it is impossible
to distinguish these two effects from  each other.
   One fact which seems to offer something more positive,
was ascertained  by Erman.  This  physiologist, having
put a piece  of an eel in a narrow tube of glass containing
water,  saw at each contraction  which a stream of gal-
vanism produced, the water evidently sink, and rise again
during the  relaxation. 
192
ADDITIONS TO THE
   Besides, this  question, with which authors have  been
much engaged,  has  been resolved by them in all ways.
Some have maintained that the  muscle was diminished,
others have  pretended that it was  increased, and finally
others have  been certain,  that it was neither increased
nor diminished; it would be difficult to imagine  a fourth
opinion.

 Stale of the  Circulation in  the  Muscles during
                     Contraction.

   Page 39S.—" The blood contained in the vessels of the
muscles, especially in the veins, is in part pressed Out; the
increase of the  flow of blood  by the motions of  the arm
in the operation of bleeding proves this fact."

   This fact  is  differently explained by  many physiolo-
gists, who admit that the circulation becomes more rapid
in a muscle that is in a state of contraction, and attribute
to this circumstance the  increase of the  jet of blood  by
the motions in the operation of bleeding.  But the greater
activity of the circulation  during the  muscular  contrac-
tion  is far  from  being rigorously demonstrated.  Let us
see in fact  upon what this assertion rests.
   1st. It is evident  that the fact of the bleeding cannot
establish this opinion, since we have  just  seen that it  is
easy  to account for it  without being obliged  to  have
recourse  to  it ;  in  fact, the muscles  being increased in
thickness  in their contraction  must necessarily compress
the deep-seated  veins, by  the resistance of the  aponeu-
roses of covering, which then perform the office of a liga-
ture  in relation to these veins ;  hence it is not surprising
that  the blood goes in greater  quantity into the sub-cuta-
ncous veins. 
MUSCULAR SYSTEM OF ANIMAL LIFE.     193
  2d. The panting, which always follows great motions,
has been cited ;  it is, it is said, because the circulation of
the blood through the muscles  is more rapid, and  the
lungs consequently receive it in greater abundance, that
respiration is  accelerated  in  this  case;  thus the muscles
which serve  for this  function are then in extreme activ-
ity, and sometimes finally become so  fatigued that respi-
ration can be  no longer supported by them, as is  seen in
animals  pursued  in  the  chase,  who at last fall down.
But it is necessary to take into account here a principal
circumstance, omitted in the  explanation that has  been
given of  this phenomenon ;  it is, that the parietes of the
thorax,  contracted and immoveable,  are  to  serve as a
fixed point for the action  of  all the muscles of the body,
in all violent and extensive  motions.  Now this  circum-
stance explains  all  the  others;  the  circulation  is more
rapid, because the vessels being compressed in the chest,
less blood can go through them in a given  time ; respi-
ration is panting, because  the permanent contraction of its
muscles  impedes inspiration, and it is necessary that its
frequency should compensate for its  want of  extent;
finally the muscles of inspiration are fatigued by the force
with which  they are compelled to  resist all the other
muscles  of the  body.  The more rapid passage of the
blood in the  muscles is not then, in this case, an immedi-
ate consequence of their contraction, but is owing on the
contrary  to  a cause,  which to a certain extent  is foreign
to it.
   From  these different considerations,  it is evident, that
nothing  proves  that the circulation of the blood is more
active in  a muscle at the time of its contraction, as has
however been almost  generally thought.   The various
hypotheses,  by  means of which it  has been pretended
that  the  muscular action could  be  explained, have no
              25 
194
ADDITIONS TO THE
 doubt given  rise to this idea, which  could  never have
 arisen from observation, and of which it has been thought
 that proofs were afterwards found, when the  imagination
 had once  created  it.   It is thus, that Prochaska could
 hardly refuse to admit it, when he supposed, very ingeni-
 ously  it is true, that the shortening of the  muscles in
 their contraction depended solely upon this, that the  ves-
 sels placed transversely in  the substance of  their fibres,
 suddenly distended by the  fluids  which entered them,
 separated these fibres  and  made them suddenly fold up.

           State of the Muscles after Death.

   Page 419.—" It appears that these different states" (of
 rigidity or  relaxation) " depend upon the kind of death,
 upon the phenomena  that accompany the last moments.
 But how do they  precisely happen ?  It is an object of
 interesting research."

   The  Physiological Researches of Nysten and  one of
 the. synoptical tables of Chaussier may  be consulted with
 advantage upon this point.   Muscular rigidity is constant
 after death ; it is a consequence of irritability ; the muscles
 are in a  state of real  contraction.   This  phenomenon
 appears also to  be connected with  the  coagulation of the
 blood ;  for all the causes which retard or promote the  one
 have the same action upon the other; a warm bath, by pre-
 serving the heat in a dead body, and by preventing the
 coagulation  of the fluids, keeps up also  the suppleness of
the muscles.  But  what proves that cold is not  the sole
cause of the rigidity,  is that this disappears after some
time, and that  the  muscles are relaxed of  themselves
before the period of putrefaction.   The  kind of death  has
an influence upon the duration  of the contraction and  the 
       MUSCULAR SYSTEM OF ANIMAL LIFE.        195

time in which it comes on.   In diseases with exhaustion,
such as  scurvy and gangrenous  diseases, the rigidity
appears very soon after death, but soon gives way.   On
the contrary, after  acute diseases and  sudden deaths, it
does not come on  for one or two days, but continues a
much  longer  time ;  it  is also greater  in  the  last case.
Besides, the muscles are not the only seat of this rigidity,
the cellular texture and the fibrous parts partake of it also.
The muscles of organic life experience it, like the exter-
nal muscles,  although it is in  the latter that it is particu-
larly observed.

Morbid Anatomy of the Muscular System of Animal
                         Life.

   The alterations which the  muscles of animal life under-
go will be described with those of the muscles of organic
life. 
 
ADDITIONS
TO THE
MUSCULAR SYSTEM OF  ORGANIC LIFE.
Influence of the Nervous System upon the Muscles of
                  Organic Life.

  Page 24, vol. 3d.—" The cerebral and  nervous influ-
ence upon the organic muscles is not known  to us.—It
is however  real to a certain extent, since it is necessary
that the nerves which enter into the composition of these
muscles should be  of some use; but we are ignorant  of
this use."

  We have seen  in  the muscular system of animal life,
that the influence of the  nerves upon the irritability of
this system  cannot  be easily determined.   The same
question recurs here, and is even more complicated.   In 
198
ADDITIONS TO THE
 fact, in the other system, there was at least an  evident
 action on the part of the brain  and nerves in animal con-
 tractility ; in this, this action not only becomes doubtful,
 but the same difficulty exists, and even a greater one per-
 haps, in relation to the part which the nerves perform in
 the organic contractility.   It may  be asked, 1st, if the
 brain has  any  influence upon  the  contractility  of the
 muscles of organic life ; 2d, if  the spinal marrow be not
 necessary to the exercise of this contractility ;  3d, if the
 nerves be purely passive in this phenomenon, so that this
 property is, according to the expression of  Haller, inhe-
 rent in the fibre of these muscles.
   The  considerations offered by Bichat show that the
 muscles of organic life are independent, in their action, of
 cerebral influence ;  but they do not prove that this cannot
 be exerted under some  circumstances.   Many of the  facts
 which he has brought  forward  tend, on the contrary, to
 demonstrate this influence.   The passions are a remarka-
 ble example of it.  It appears to me to be extremely  pro-
 bable that, when in a strong emotion, for  example,  the
 motions of the heart are accelerated, it  takes place only
 because the brain reacts upon this organ and transmits to
 it the  impression which it has received.   Placing the
 primitive  seat of the  passions in the organs of internal
 life, is forgetting, it seems to me, that the brain is the sole
 organ of the perceptions, and that the passions are always
 the consequence of these last.   This however is  not the
 place to discuss this question ; it is sufficient  to show that
 the action  of the heart may in this case be entirely  sub-
jected to that of the brain.   Those cases, rare ones indeed,
 in  which the will can suspend  the  action of the first of
 these organs, seem  to belong to the same cause.  Bayle,
 who possessed this singular faculty, could put it in exer-
cise instantaneously and with the same ease that he could 
       MUSCULAR SYSTEM OF ORGANIC LIFE.       199

move a muscle of animal life ; now, if this depended on
the suspension of respiration, it would require some time
for the phenomenon to take place.  Moreover, the heart
is not the only organ which thus obeys, in some cases, the
influence of the brain.  Many facts show that the stomach,
intestines, bladder and even  the womb are also sensible
to this influence ;  we know not, it is true, if it be  by the
nerves that it is transmitted ; but as these agents are the
only  means  of  communication  of  the  brain with these
different organs, every thing leads to the  belief that such
is their use.  It must however be acknowledged that we
want direct experiments  in  order  to place this beyond
doubt.  On the contrary,  those that have been hitherto
made teach us,  that  the brain can be removed without
diminishing at all the action of the muscles of organic life,
if care be taken at the same  time to support respiration.
What can we conclude from these opposite facts and from
those stated by Bichat ?  that no doubt the cerebral influ-
ence is not absolutely necessary to the contraction of these
muscles, but that  it can  modify it under  certain circum-
stances.   We shall now see that it is nearly the same
with regard to the spinal marrow.
   On the one hand, Legallois, by numerous experiments
which have already been noticed in the article upon the
nervous system  of organic  life, has  pretended to prove
that the  heart receives, by the  great sympathetic, from
every  part of the spinal marrow, the  principle  of its
motion,  which is annihilated when  this is  wholly de-
stroyed ; on the other hand, various facts, which have been
stated in this same article, from the experiments of Clift
and Wilson Philip, demonstrate that often, notwithstand-
ing the absence of the spinal marrow,  the  heart continues
its  action ; that some lesions of the  spinal marrow have
more influence than others upon this organ ; that, accord- 
200
ADDITIONS TO THE
ing to the age and the species of the animal, great differ-
ences in the results are observed, &c.   Whence it is seen
that the organic contractility, though independent to a
certain extent of the  spinal marrow,  is  in  some  case
influenced by it.
  Finally, is the continuance  of this  contractility, not-
withstanding the destruction of the brain or spinal mar-
row,  a proof that  the muscular fibre is of itself endowed
with  it, independent of all nervous influence, as Haller
thought?  Certainly not, since the  nerves  exist and  can
still act insulatedly in this case.   Nothing  is opposed to
our admitting here the same hypothesis as in the muscular
system of animal life, viz.  that the  muscles derive from
the nervous system  the principle of their  action ; but I
know of no fact which proves  this in an incontestable
manner.

       Duration of the  Organic Contractility.

  Page  38.—" This duration is longer  than that of the
animal contractility.   When the spinal marrow is irritated,
the external muscles remain immoveable, whilst the inter-
nal ones are still in activity."

  This comparison has for its object only the two  species
of contractility, considered in the two corresponding sys-
tems.   But that of animal life  enjoys not only the con-
tractility of this name, but possesses also, according to the
distinction made by  Bichat, organic contractility.  Now
this differs, as it respects its duration after death, in the
different muscles of the two systems.
  Haller,  who perceived this fact, says  that it is the
heart which  remains the longest sensible to the action of
stimuli; that next to it, the  intestines are  the^slowest in 
         MUSCULAR SYSTEM OF ORGANIC LIFE.     201

losing the faculty of contracting ; that the stomach comes
next and then the diaphragm,  and  that finally the exter-
nal muscles are  the first  in  which this  faculty is extin-
guished.  He adds,  that in some  cases, the  intestines ap-
peared to him to preserve their irritability longer than the
heart.   New researches,  for which we are  indebted par-
ticularly to Nysten, prove  that this  order  is not in fact
exact.   The kind of death,  the nature of the stimulus em-
ployed, &c. make  the  duration of the irritability vary in
the different muscles ;  it is thus that the heart for a longer
time obeys the irritation which  arises from a puncture with
the point of an instrument, whilst  the voluntary muscles
are longer sensible to the stimulus of Galvanism.
   A numerous series of experiments has enabled Nysten
to establish the  following order, which is  very different
from  that of Haller ;  1st, the left ventricle of the  heart,
which gives for the  shortest time signs of irritability, and
is thus found at the bottom of the scale ; 2d, the large in-
testines ; 3d, the small intestines ; 4th, the  stomach ; 5th,
the bladder ; 6th, the  right  ventricle;  7th, the oesopha-
gus;  8th,  the iris, whose motions  this physiologist has
also  examined ; 9th,  the muscles  of the  trunk ;  10th,
those of the inferior extremities ; 11th, those of the supe-
rior  extremities ;  12th, finally, the auricles, the contrac-
tility of which is preserved after this property has ceased
in all  the  other parts; it is extinguished in the last place
in the left auricle, a fact  very  long known, and which is
mentioned by Galen.

         Force of the Dilatation of the Muscles.

   Page 54.—" It  appears then very probable that the
dilatation of the organic muscles is a phenomenon as vital
as their contraction."
26 
202
ADDITIONS TO THE
  Without absolutely denying that the internal  or invol-
untary muscles  can  be dilated  and the  voluntary  ones
elongated,  by a peculiar  vital action, analogous to the
contraction of these same muscles, I would observe that
most  of the facts which tend to  prove this action can be
explained in another way, and often depend on causes
which are wholly foreign to it,  and which have  been
overlooked by those who admit this action.  It is  thus
that Barthez  cites as phenomena of this kind, owing to a
sort of active repulsion opposed to the  attraction which
predominates in the shortening of  the muscular fibres, the
elongation of the trunk of the elephant, that  of reptiles,
worms, &c. in the act of  crawding, and even that of the
tongue.  It is evident that,  in all these cases, the elonga-
tion is but a secondary effect of the shortening of certain
muscles, which  by their  arrangement, cannot produce it
except by a real dilatation.   The leech, for example, has
longitudinal fibres, the effect of which is to shorten it, but
as it has at the same time circular fibres  which cannot be
contracted without elongating it,  the space  which  these
fibres  enclose  evidently  increasing in  one  direction,
whilst it diminishes in another.   It  is the same with  re-
gard to worms, &c.   The trunk of the elephant also con-
tains two sets of fibres, the longitudinal ones to shorten it,
and the radiated ones serve to elongate it, and it  is not to
the dilatation of the first that this last effect must be at-
tributed.
   It is for the want of having known the  true arrange^
ment  of the muscular  fibres in certain parts, and not
having appreciated the different effects of the contraction
of these  fibres according to  the  direction they take, that
some have been led to  give them a force of expansion
which by no  means  appears  to  be  inherent  in them.
What takes  place in  the intestine confirms this  idea; 
MUSCULAR SYSTEM OF ORGANIC LIFE.
203
there is no doubt that the alternate extension and contrac-
tion which agitate this viscus depend on the alternate con-
traction of its  longitudinal and  circular fibres; yet this
fact is one of those wdiich has been given in proof of the
active dilatation of the muscles.
  F.  Meckel  has presented some  new  considerations in
support of  the latter, drawn from  the different  states in
which the muscles  are found after death, from the mo-
tions  which are  observed  in the iris, from the variable
dimensions of the pupil in the dead body, &c.; but if we
except from them  the iris, whose  motions are, I think,
but little known, and whose muscular  nature is moreover
far  from being  demonstrated, the contraction alone of the
muscles perfectly explains  almost  all the phenomena of
which they are the  seat.  A single  one,  already cited by
Bichat,  seems at  first favourable to the active  elongation
of the fibres, inasmuch as it appears  hitherto inexplicable ;
it is the force with  which the heart rises up and tends to
dilate itself, even when the blood does not enter its inte-
rior.  But is this fact, though obscure, more conclusive,
and may it not be owing, like the others, to some partic-
ular cause which is  unknown to us ? Who can say that
the diastole and  systole will not be  one day as simple
phenomena, as  those  of the  contraction of a "voluntary
muscle ? 
204
ADDITIONS TO THE
     MORBID ANATOMY OF  THE  MUSCULAR SYSTEM.

  The alterations  common  to  the two great divisions of
this  system may  be  united in one  description.   There
are a few particular ones, which will be noticed.

        I. Alterations in the External Forms.

  Excess of nutrition is common in the muscles;  but it
is hardly any where but in the heart  and the bladder that
it constitutes,  properly speaking, a disease; it is charac-
terized by a remarkable increase of size and often of den-
sity.  Atrophy often  takes place in the external muscles,
from the want of exercise, distension  or some other cause.
There is frequently joined with it a discolouration of  the
fleshy fibres,  which  has been  taken for  a fatty state, as
Bichat has already observed.   The pretended fatty alter-
ation of  the muscles  does not appear to  me to exist, at
least I know  of no instance which cannot be referred to
the preceding state, in which, the fleshy fibres disappear-
ing in part, the intermuscular fat predominates and is con-
founded in its colour  with the muscle itself,  that  has  be-
come yellowish.   But we find  by analysis fibrin in these
muscles; by putting some  of it on brown paper,  distinct
fibres are discovered after the animal oil  has been absorb-
ed, &c.   In  the heart, atrophy occasions the dilatation of
this organ, its passive aneurism.
  The muscles lose their consistency under many  circum-
stances ;  the  heart   is very  subject to  this  alteration,
which has  been described by  M. Laennec in his excel-
lent  work entitled Traite  de  VAuscultation  Mediate,
in which will be found a great number of interesting facts
upon the diseases  of  this viscus.  The softening  of  the 
        MUSCULAR SYSTEM OF ORGANIC LIFE.       205

muscles may bring  on their rupture ;  that of the heart
has been often observed in similar cases, especially in old
people; it has been the  subject of a particular work of
M. Rostan.
   The muscular fibres are sometimes elongated from the
effect of different diseases ;  there results from it a more
or less  evident weakness of their action.  This forced
elongation of the muscles often exists at the same time
with the shortening  of the antagonists,  which is then the
cause of it; it is sufficient, in this case, to  counterbalance
the latter in order to restore to  the former their contractile
faculty;  it is in this way that we sometimes succeed in
remedying the  permanent  flexion  of the  fingers,  by
straightening  them  to such  an extent that the  extensors
can  contract again; the  same thing applies  to the  cure
of club-feet, when it is possible to bring back the axis of
the limb to its  primitive direction.
   Shortening has not 'the same inconveniences; it  may
extend very far without being  perceived by the contrac-
tility, as proved by a preparation  in Hunter's collection,
in which the humerus had experienced a considerable loss
of substance.   It seems  on  the contrary that this short-
ening power was increased in it; at  least  it is then in
continual  exercise.   This sort of retraction  is very fre-
quent, and is most  often connected with  a weakness of
the  antagonists.  Contractions  from the  scurvy, certain
morbid curvatures of the trunk, club-feet, that we have
just noticed, strabismus, and the retraction of the muscles
of the leg by a continual pain  in this part, are  examples
of it.  The little finger is often thus retracted.
   Much  has been said of the  displacements of the mus-
cles,  of luxations, and  hernias  of these  organs.  What
Poutean has  written upon this subject may be advantage-
ously examined. 
206               ADDITIONS TO THE
         II. Alterations in the Organization.

  Inflammation of the muscular texture  is still doubtful.
Purulent centres have been found in the different regions
of this system, but they may have their seat in the cellu-
lar texture interposed between its fibres.
  A muscle cut transversely retracts powerfully, as has
been seen elsewhere.   But the  inferior part is often para-
lyzed by this division, because a nerve is left in the supe-
rior, at that part of it in which it usually penetrates the
muscle; the latter preserves on the contrary its irritability;
the retraction, which is so evident in amputation, depends
in a great measure on this cause. It would  be the reverse,
and the inferior alone would  contract if  the division  had
been made higher up.   In  all cases, to these phenomena
succeed  those of reunion.  A  new fibrous texture  fills
the space between the two  ends,  which it unites firmly
together ; if it be  short, it does not injure the contrac-
tion, otherwise the  muscle would gain, as  has been said ;
if the intermediate  substance be long and extensible, the
motions are more or less injured.
  Transformations  are hardly ever  seen in the muscles.
I have however found in  them fibrous and  osseous tu-
mours, wdiich  had a knotty appearance, analogous to that
of the tumours of this kind which are found in the womb.
We have seen above what  should be thought of the fatty
transformation.
   Morbid alterations (degenerations) are also very rare
in this system.  Hydatids may sometimes  be produced  in
/♦ ; they arc common in hogs. 
MUSCULAR SYSTEM OF ORGANIC LIFE.     207
         III. Alterations in the Development.

  The muscles of animal life have been wholly  wanting-
in a foetus ; there was under the skin, only a fatty mass,
formed of infiltrated cellular texture  more or less consis
tent; at other times, a  part of these  muscles is  wanting.
The  heart, in very rare  cases it is true, has also exhibited
this anomaly,  very frequent in some  muscles taken sepa-
rately.  Nothing is  more  variable, besides,  than  the ar-
rangement of the muscular system, considered in relation
to its external forms. We  often find supernumerary mus-
cles,  or those  which should exist are removed, by their
conformation, from the natural order. The attachments,
direction, size and structure exhibit an infinite number of
varieties,  all of which are  in the province of descriptive
anatomy.   The muscles of organic  life  are not exempt
from these varieties ;  the heart alone exhibits a great
number of them.
   Some authors have spoken of muscular transformations ;
but the examples they  have adduced  are too vague to be
characterized.   There  seems to be  a preternatural  de-
velopment of the muscular texture in the womb,  during
pregnancy, and in the round  ligaments,  at  the same
period. 
 
ADDITIONS
TO THE
MUCOUS  SYSTEM.
           Villi of the Mucous Membranes.

  Page 85.—" The delicacy of these elongations conceals
their structure, even from our microscopical instruments,
agents from which anatomy and physiology do not appear
to me to have derived much assistance, because when we
see obscurely, each sees in his own way and  according to
his own wishes."

  A great number of observers, both ancient and modern,
agree in many points  in relation to the arrangement of
these villi; they differ, it is true, upon others, but it is
easy to see that oftentimes the foundation of their obser-
vation is the same, and that the whole difference consists
in the  manner in which  they have  given an account of
             27 
210
ADDITIONS TO THE
them.   The intestinal villi have been the particular object
of their researches.   The following is what  is the least
obscure respecting the nature of these elongations.
  The villi of the mucous membranes, examined with a
microscope, resemble the fibrous parts of the roots of cer-
tain  trees.  Yet their form appears to be rather flat than
round, and the name of leaflets (folioles) which has been
given to them latterly is perhaps better  in this respect
than that of villi.  Lieberkuhn had already noticed this
arrangement  in  man, but he admitted that those of ani-
mals were cylindrical, and consequently filamentous  or
villous.   They terminate in a point,  which,  joined  to
their flattened form,  has led some to compare them, from
their appearance, to  the leaves of the grasses.   Rudolphi
says that they are laminae,  small scales which furnish the
whole interior of the intestine ; this is not very far from
what we have just said.
  The structure of these elongations is the point that has
been the most contested.  We know what was  the vesicle
of Lieberkuhn ; this anatomist having  observed that the
intestinal villi were swollen by injection, and that the air
driven in diffused itself in them and gave them a spongy-
appearance, thought  that he might conclude from it that
they were in  a great measure formed of a kind of cellular
vesicle,  in which the vessels terminated, particularly the
lymphatics.   Hewson  has  made observations similar  to
those of Lieberkuhn, but he has not drawn the  same con-
clusion from them ; according to him, the injection makes
the villi swell, and produces in them a phenomenon simi-
lar to that of erection ; but this arises from their being
entirely composed of a net-work of vessels, of a sort  of
plexus similar to that which forms  the erectile textures.
This opinion  also is  rejected by Rudolphi, Mess. Cuvier,
Alb. Meckel  and many other modern anatomists, who do 
MUCOUS SYSTEM.
211
not allow that these elongations contain vessels, at least
apparent ones.  A viscid  matter, a kind of jelly, a sub-
stance without form or organization, constitutes, accord-
ing to these authors,  the  villi, which have exhibited to
them with a microscope only this substance, and moreover
opake globules situated below it.  This matter is capable
of being soaked and then  becomes spongy ; this soaking
can take place from  within, that is to say, on  the side of
the vessels,  as well as  from without, or on  the surface of
the mucous  membrane.  The lymphatic vessels may arise
from  this substance, which Alb. Meckel compares to that
which constitutes very young vegetables at  the period of
their development.  This  description, if it be  accurate,
would agree very well with the facts previously observed,
and would  enable us  to explain how  Lieberkuhn  saw a
vesicle, how Hewson found vessels, &c.  There is, accord-
ing to Alb.  Meekel, a circumstance which may account
for the various forms  that have  been  attributed to the
villi; it is  that the leaflets they represent  are variously
folded,  and twisted, and thus assume a variable aspect,
which depends on their situation at the moment they are
observed.   It is owing to  this that Hedwig  calls them
cylindrical,  digitiform, terminated by an obtuse summit;
that others have compared  them to small clubs, &c.
  Many anatomists are confident that there  are apertures
on the summit of the villi,  and that they are  the orifices
of the lymphatic vessels.  They are not however agreed
as to  the number of these orifices.   Bleuland and Hedwig
allow but one ;  Cruikshank and Soemmering have  seen
from  six to ten.   Hewson  pretends that these apertures
do not become distinct until the villi are rendered more
prominent,  as  happens from injection ; he supposes that
it is the same during life, and  thus explains absorption by
the erection of which  he believes these elongations sus- 
212
ADDITIONS TO THE
 ceptible.  Those,  who admit the opinion that was last
 stated, reject all kinds of openings  similar to absorbent
 orifices;  the soft matter, which has been  noticed above,
 is in the place of them, according to this hypothesis.
   It is generally thought that the villi  receive nerves ;
 but this  is  rather from  a presumed  analogy with the
 papillae and on  account of the  sensibility of which  they
 are  the  seat, than the  result  of inspection.   M. Ribes
 has injected veins  in them  from the  vena  porta;  we
 have seen that these elongations can be injected from the
 arteries ; their lymphatic vessels  are also evident;  in
 order  to  see them, it is  only necessary to immerse the
 membrane in alkohol; the fluids which  they contain are
 coagulated and render them more apparent.

                   Mucous  Glands.

   Page 88.—" I cannot  say  whether nerves penetrate
 them ; analogy indicates it, for all the  principal glands
 receive them."

  These small sacs are now distinguished from the glands,
and  described under the name of follicles, which agrees
much better  with their nature.   They appear  in fact to
be  formed by a sort of inversion  of the membrane in
which they are  seated, and which being folded, at the
place where they arc, beneath its free surface, constitutes
in this a real cul-de-sac, terminated  by an orifice open
upon this surface.  This arrangement  is very evident in
the  sebaceous  follicles on  the  skin,  with  which  the
mucous ones  have so  great  an  analogy.   These last ex-
hibit it also  evidently at their origin ;  there,  as in  all
the points where their epidermis is  distinct, we can raise
this up entire with the elongations which  it forms in  the 
MUCOUS SYSTEM.
213
follicles.  This is rendered still more evident in diseases,
as we shall see in the article upon the dermoid system.
  Thus the mucous follicles must have a structure  analo-
gous  to  that of the  mucous  glands of which  they form
a part, though it  is difficult to perceive this  structure ;
they have no excretory duct ;  only when they are situat-
ed  below the chorion, in the subjacent  cellular  texture,
the neck of them being more  or less elongated, forms a
kind of tube.   The  orifice  by which they  terminate  is
uniformly more narrow than their bottom, and furnished
with villi similar to those of the neighbouring parts.  Sir
Everard Home has given very good drawings  of these
different objects.
  Most of these small bodies are insulated and irregularly
disseminated,  in  greater  or  less number, in  the whole
extent of the mucous system.   I say in the whole extent,
for  we have seen  where they are  but  little apparent,
analogy induces us to admit their existence because secre-
tion is constantly going  on  there.   Besides,  their  size
being  excessively variable in the parts which are mani-
festly provided with them, it is natural to think that  if
they are not seen in the others, it is simply because their
size is such as  to  conceal them from the  sight.  More-
over, what reasoning indicates, is already in part proved
by  inspection ; the microscope has enabled  us to see
follicles in many membranes in which they could not be
distinguished by the  naked eye, especially in the pituitary
membrane; there is  produced  on the skin  little bunches,
tumours formed  by the  development of the follicles, in
places where they had not been before met  with, &c.  But
in some parts, the follicles, far  from  being thus insulated
and often discoverable with  difficulty, are agglomerated
and constitute  by their assemblage  masses  of different
forms, and the arrangement of which varies; it  is  this 
 214              ADDITIONS TO THE

 which  has  led to the distinction of the follicles  into
 simple, which  are the  first, and into compound, among
 which are ranked the caruncula  lachrymalis, the folli-
 cles of Meibomius, the arytenoid glands, the  amygdalae,
 the molar and  buccal glands, the glandulse  agminatas
 of the intestines,  the prostrate, &c.   Sometimes each of
 the simple follicles which compose these last, has its own
 orifice open  upon the mucous surface, as is seen  in  the
 caruncle.  Sometimes, as in the glands of Meibomius,
 they open into  each other, so that the last pours out  the
 product of the  secretion of the whole.  Sometimes their
 openings  are met with at the  bottom of a  sort of fold
 which the  mucous membrane  makes,  an example  of
 which is furnished by the amygdalae $ the mucous lacunae
 belong also to this  last kind ;  they may be  considered, as
 well as the mucous folds of the amygdalae and the foramen
 caecum  of the  tongue,  as great follicles which receive
 smaller ones ; this  is very well  seen  in  the urethra, for
 example.   Finally, the  molar glands and the prostate
 have  a real  ramified- excretory duct, like the glands;
 thus these organs  partake of the glandular nature, and
 theirs  seem  as it were, to hold the  middle space between
 this and that of the follicles properly  so called.
  The mucous membrane of the stomach, that of  the
 oesophagus  and of the  small  intestines  exhibit,  besides
these follicles,  small superficial cavities, slight  depres-
 sions, which Hewson, who first observed them, compares
to the cells of the  bees, and designates this arrangement
by the name of the alveolar  structure.   These  alveolae
 have  been  more  recently  described by  Sir  Everard
 ilomc ; they can  only be seen with a microscope ;  in
 some places, however, they are visible to  the naked eye.
 They do not appear to differ from the follicles but in this,
 fhat their aperture is broader than their  bottom, the fold 
MUCOUS SYSTEM.
215
of the mucous membrane  being of small  extent, which
forms  them ;  they are, as it  were, the  rudiments of the
follicles.   Their number  is few at  the bottom  of the
oesophagus, where they begin to be  perceived, between
the folds of this canal; it increases in the stomach and
especially in the duodenum ; in  this intestine and  in the
stomach, the depressions have nearly the  same  breadth
as the interstices between them ;  they differ in this from
the alveolae or bees' cells  which are in fact more nume-
rous,  and  whose interstices are much  smaller.  Their
parietes are smooth and rounded in the oesophagus and
in the  neighbouring  portion of the  stomach ; they be-
come unequal as we examine towards the intestines, and
are furnished  with small leaflets (folioles) that are more
and more evident.
   Sir  Everard Home  has  examined  with a microscope
the digestive  surfaces  of  different animals.   It follows
from  his observations, that, in animals who are nourished
by vegetable  substances, the follicles  of  these  surfaces
have  a more  complicated structure, are provided with
numerous villi at their orifices, and secrete  a more active
juice; that animals, on the contrary,  wdiose nourishment
is derived from the  animal kingdom, have only the
alveolar depressions for follicles ;  that  we may distinguish,
in this respect, three  species of follicles which exhibit
three different degrees of complication ; 1st, those which
pour  out  a fluid of very great activity, such  as those in
the ostrich ; 2d, those of man and  the other  omnivorous
animals ;  3d,  those  of which we  find the type  in the
Java  swallow, which furnishes  a  matter  that possesses
scarcely any solvent power, and has  in return very evi-
dent nutritive properties.
   The secretion which takes place in  the mucous glands,
united to that of the sebaceous ghnds,  constitutes one  of 
216               ADDITIONS TO THE

the three  principal kinds  of  secretion established by M.
Chaussier in his  synoptical tables  viz. the follicular
secretion.  It differs in  fact in many  characters from
the perspiratory secretion or exhalation properly called,
as well as from  the glandular,  which  it  resembles in
others ; 1st, as in  the first, the secreted fluid appears to
be brought  directly by the extremities  of the  arteries ;
2d, this fluid, after having  remained  a  certain  time in
the cavity of  the follicle, and  having no doubt  been
elaborated there anew,  is thrown out, as in most of the
glands,  by the peculiar action of  the  organ which  has
furnished it.

         Development of the Mucous System.

   Page  125.—" The development of  the  mucous  sys-
tem follows  in general  the laws  of that of the organs
to which it  belongs.  Early in  the gastric  apparatus,
later  in the  pulmonary and that of generation, it seems
in its growth rather to obey  the impulse it receives, than
to give one to what surrounds it."

   The arrangement of the mucous system is very differ-
ent in the first periods  of conception, from  what it  will
be afterwards.  This system appears to be continuous at
this period, as well as the cutaneous, with the membranes
of the ovum ;  such at least seems to be  the result of the
observations of Wolff, Oken, Meckel and others.
   Wolff has traced  the development of the intestine  in
the chick.  He has seen  that this canal is at first very
short, straight, open before, and  continuous in this direc-
tion,  with the  vitellary membrane, not  having  any very
precise limit to indicate the place  wliere one  terminates
and the  other  begins ;  that  afterwards  a contraction de- 
MUCOUS SYSTEM.
217
signates this place, which is  elongated  more  and more,
in proportion  as the  intestine  grows at  the  expense of
the yolk, so that at birth these  two  parts  hold  together
only by a narrow  pedicle, which  disappears  completely
when  the yolk has been  entirely absorbed.  Now, the
umbilical vesicle appears to perform  in  man, in  the first
periods of the intra-uterine life, the  same  uses  that  the
yolk  or  the vitellary membrane  does in  birds ; many
direct facts tend even  to  prove, that it is in the same
relation as  this last  to  the  intestine, though  it may be
very difficult to be sure of it, because these first periods
are passed very rapidly in the mammalia, and  the foetus
soon acquires another mode of existence, wholly different
from that of birds.   However, 1st, the umbilical vesicle
is so much the larger in  relation to  the foetus, and  so
much nearer  the umbilicus, in proportion as the embryo
is younger;   2d,  the intestine is for a  long   time  in
part contained in  the  base  of the  umbilical cord, and
afterwards sends sometimes an elongation which extends
to the  umbilicus ; at  other times  there is  seen a small
duct detached  from the umbilical vesicle, and  directed
from  the side of the umbilicus,  for a certain  distance,
along the cord ;  3d, various anatomists  have  seen  this
vesicle  communicating with the  intestine in foetuses of
the mammalia ; 4th, Meckel  says that he has  met with
a similar communication, in man.
   From  all  these  considerations, it may be  admitted,
with  Oken, Meckel, &c. that  what is  evident  in regard
to  birds, reptiles and fishes, takes place also in  man, and
that the  alimentary  mucous  membrane, by  being  con-
founded with the umbilical  vesicle, makes,  in the be-
ginning, an integrant part of the ovum.   The same may
be  said  of the genito-urinary  membrane,  the bladder
having intimate connexions with the allantois;  the skin,
              28 
Big
ADDITIONS TO  THE
 on its part, making a continuation with the amnios.  From
 this it results, 1st, that these organs are among the earliest
 in their development, if they be not even formed  before
 all the other parts ;  2d, that the embryo is in nowise dis-
 tinct from the ovum in the first periods ;  3d,  that its two
 integuments,  viz. the  external formed by the  skin, and
 the internal  which  the  mucous  membrane  represents,
 instead of imitating, as in the  adult, a double  continu-
 ous sac,  folded  at  its two  extremities,  are  as it were
 but two  semi-canals  whose circumference is  wanting in
 front.
   The part of the intestine, which  corresponds originally
 to the umbilical vesicle, and  which serves as a  point of
 departure for  the development of  the  rest of the  canal,
 remains to be determined.  According to Oken, it is the
 caecum ;  and from this point the vesicle sends two elon-
 gations which form  the stomachal and  anal intestines.
 Meckel thinks that it must be the ileum, because it is so
 in birds, and  because this intestine often exhibits  appen-
 dices which are  regarded as  remains of the  vesicle, and
 because moreover the caecum  does not exist in all  the
 mammalia.  It is evident that these are but conjectures.
   Besides, if  it be  true that the  mucous system com-
 mences by having the arrangement we have pointed out,
 great obscurity still hangs over the manner of its ulterior
 development,  and the way in which  this  semi-canal, of
 a very limited length, open in its whole  extent, is com-
 pleted in front on the one hand, and is changed on  the
 other into a long tube,  no longer holding to  the vesicle
 but  by a  narrow  and almost  impreceptible  canal.   It
 has also been  attempted to  explain  in another wray the
 formation  of  Ibis  system.  Some have  said  that  the
 cavities which it lines are hollowed out from without
inwards, and that it  was the  skin, by plunging gradually 
MUCOUS SYSTEM.
219
into 'lie substance of the embryo, which gave  rise to
the mucous membranes ; it is on this account, say they,
that the intestine is subject to interruptions in  its continu-
ity, when its  two portions, going, one from  the  mouth,
and the other from  the  anus, are  not perfectly united.
There is nothing  to  prove  this assertion, which is  also
contrary to many facts.   Lucae has  given another hy-
pothesis, founded  upon this, that the cavity of the intes-
tine is often interrupted  in many places ; this  proves,
according to him, that this canal is at first, composed, like
the  vessels, of insulated  parts,  which afterwards go  to
meet  each  other, and  are finally confounded.  The  ap-
pendices of the intestine  are  formed  when  these parts,
instead of  joining to the end,  are united together by
one of their sides.   Tiedemann  and  Meckel admit this
opinion to a certain extent, modifying  it in that  part
which  makes  the  intestine  proceed from the umbilical
vesicle.  On the whole, it appears  that new researches
are required  on this point; only the  occlusions of the
intestinal  tube  do not appear  to  me  by any means to
demonstrate what authors have advanced ; these occlu-
sions do not take place till after  the complete develop-
ment  of the intestine.
   There  are neither mucous villi nor folds in  the first
periods of conception.  Meckel  states  that the  villi com-
mence by longitudinal folds, which are afterwards divid-
 ed into small insulated prominences, to form them. 
220
ADDITIONS TO THE
      MORBID ANATOMY OF THE MUCOUS SYSTEM.

         I.  Alterations in the External Forms.

  The mucous ducts are dilated and contracted under
many circumstances ; most  of these  have been  noticed
in the article on the Properties of Texture of this system.
These  changes of dimension  in  diseases  almost always
depend  on  an obstacle  to the  course of the substances
which pass through these ducts in a state of health ; this
is evident with regard to the excretories; the least exten-
sible, such as the  urethra, may form, in this case, sacs  or
dilatations of more or less considerable size, before break-
ing ; the  bottom  of the mucous  lacunae appears to  be
sometimes the particular seat of these  dilatations.   Some-
times the obstacle is foreign  to the  mucous membrane,
and  this contracts below only because less fluid passes
over it,  and keeps it separated; sometimes  the contrac-
tion primarily occupies  this  membrane, whether owing
to  wounds, ulcers,  inflammation or  any  other cause.
In either case, as  in  that in which the fluids take  another
direction, because an accidental opening gives passage to
them, the portion situated below is  not  obliterated,  as
has been seen.
  The mucous membranes are  however capable of con-
tracting adhesions ;  but for  this it  is necessary either
that the secretion of mucus should  be suspended  there
by  inflammation,  or that the  epidermis, of those wdiich
have one, should  be destroyed.  It  is under  analogous
circumstances that the tongue has been seen to adhere
to the  corresponding parietes of the  mouth, the  vagina
to disappear by the mutual adhesion of its parietes, the 
MUCOUS SYSTEM.
221
Fallopian  and  Eustachian  tubes, the nasal  and lachry-
mal ducts, &c.  to be obliterated.   These adhesions are
however  much  less  common here  than in the serous
system.
  The mucous  membranes are  the seat of thickenings,
growths and excrescences,  which  may  be  regarded as
enlargements of their substance.  Polypi are  an altera-
tion of this kind ; they are divided, as is well known, into
many  species ;  many belong as  much  to the sub-mucous
cellular texture as to the  mucous membrane  itself, which
they only raise up ; there are some which arise from the
periosteum situated in  certain places below the mucous
membrane, and which are real fibrous  bodies ;  some are
formed by a texture which differs more or less from the
natural one, and come, in this respect, under  the altera-
tions of texture ; such are those that are called cancerous.
  Various organs, that  are covered on  the interior by
mucous membranes, are exposed  to defects of situation
and figure in which these membranes participate ; but the
latter have also some which are peculiar to themselves, ex-
amples of which are furnished in the various displacements
which the mucous membranes of the rectum, vagina, blad-
der, &c. experience in the prolapsuses, inversions, mucous
hernias, &c. of these organs.  The internal or villous coat
which lines these viscera on the interior then  leaves the
other  coats, and is  extended alone  to a  certain extent,
either through  a natural opening, or through a preterna-
tural  one  arising from a  separation of the fibres of the
nervous coat.  The preternatural anuses are almost always
complicated with this sort of displacement  to which the
mucous  system  is peculiarly disposed  from   the  slight
adhesion of its  subjacent texture, or nervous membrane
of the ancients, to the mucous  membrane  of the organs
which it contributes to form. 
222
ADDITIONS TO THE
         II. Alterations in the Organization.

  Inflammation produces in the  mucous system, besides
the alterations of colour  and the vascular development
which are  peculiar to  it, suppurations, false  membranes,
ulcerations, gangrene, &c.  Of all these phenomena, no
one is more remarkable than  the formation of the  false
membranes, analogous  to  what takes place in  the serous
membranes.  The conjunctiva in  ophthalmias  caused by
the vapour of the hydro-chloric acid, the rectum in irri-
tating injections  administered to  animals, the mucous
membrane  of the  mouth and the pharynx and that of the
air tubes in croup exhibit this alteration, in which  a soft
layer, like the skin of pork, whitish, and slightly adherent,
covers more or less uniformly  the inflamed  mucous mem-
brane.  This layer has hardly ever time to be organized ;
it  is  thrown out» before, or the inflammation is quickly
fatal ; Albers has found it vascular in croup of  a chronic
character.
  In  some cases, inflammation  seizes more particularly
upon  the mucous  follicles, which swell  and then become
very apparent; this variety has been described by Roed-
erer and Wagler.   Another form which this affection ex-
hibits, though less evidently  than on the skin, is that of
exanthema ; it is observed especially in those parts of this
system that are in the neighbourhood of the surface of the
body.
  The solutions of continuity of the mucous membranes
cicatrize like those of  the skin ;  this  is what  is seen in
some  ulcers of the mouth  and pharynx, after the excision
of excrescences  from  the genital  parts, &c.  The new
texture,  that is formed  is whiter and more resisting than 
MUCOUS SYSTEM.
223
Ihe first;  it sometimes forms filaments which may become
troublesome.
   In the  cases cited,  (in vol. 3d, of Bichat,) the mucous
system finally  experiences  the  cutaneous transformation
as this takes place whenever it  is in contact with the ex-
ternal air ; its  surface is then  dried, the mucous fluids
cease to lubricate it, the villi  disappear, an  appearance of
epidermis takes their place, and the membrane becomes,
in some measure, more stiff.  Various  parts of this sys-
tem can  also be  changed into  cartilages ; we  have cited
examples of this when treating of the cartilaginous system.
   Cancer is very frequent in the mucous system ;  it  ap-
pears under many forms ; 1st,  it constitutes excrescences
similar  in appearance to polypi, but  very different  in
their nature ; the rectum, the  nasal fossae and  the  uterus
are subject to  these tumours.   2d.  Other  tumours  are
subjacent  to the mucous membrane, which finally par-
takes of the disease, and ulcerates at their  surface; can-
eers of  the stomach, the oesophagus, the intestines and
the bladder most often assume  this form.   3d. Finally,
cancerous ulcers  have  their primitive seat in the mucous
system, begin on its superficies, and  arrive,  not for  a long
time, to the deep parts ; but little engorgement accompa-
nies them ; this variety is common on the lips, the glans
penis, and especially on the neck of the uterus.

         III. Alterations in  the Development.

   Every organic system may  be considered in  two ways,
as may be seen in the systems previously studied, in rela-
tion to the alterations that may  take place in its develop-
ments ;  1st, this  development is sometimes irregular in
the places  where  it should take place naturally ;  hence
the defects of  conformation, the anatomical  varieties and 
 224              ADDITIONS TO THE

 the anomalies of every  kind.   2d. At other times,  it
 takes place preternaturally, where it ought not  to take
 place  at  all, it  invades  other systems ;  hence  organic
 transformations and productions.  The alterations of the
 first kind  are produced by causes that are still but little
 known, by obstacles  which have arrested  the natural de-
 velopment at one of  its periods, and  have  thus preserved
 forms  which should  be only transitory, by diseases that
 the foetus has  experienced  in  the womb of the mother,
 and perhaps, in some cases, by an original mal-formation
 of  the germ, &c.  Those of the second kind take place
 almost  always in diseases ; sometimes  they are owing to
 the progress of  age.  But among the different systems,
 there are  some which appear  to  be susceptible  of  one
 kind  of alterations  only, or at least to which one kind
 alone is common, whilst others experience both equally,
 so that they might in  this respect be classed in two orders ;
 1st, on the one side would be  the cellular  system, which
 has so great a tendency  to be produced  preternaturally
 and so little to  have defects  of conformation,  and the
 serous, synovial and fibrous, which are in the same situa-
 tion ; with regard to the  nervous,  the muscular and the
 glandular, the reverse is true, this would require a subdi-
 vision ; 2d, on the other  side, the osseous, the . arterial,
 venous, &c.  Now the mucous system belongs rather to
 this last order than to the first.
   Its defects  of conformation  are numerous.   All  the
 mucous canals, without excepting the intestines, are sub-
ject to deficiencies to a greater  or less extent, and  some-
 times exhibit in  their course  interruptions the  seat of
 which  varies ;  sometimes it  is at  their exterior aperture
 that they are found imperforated ;  sometimes it is farther
 in that their  cavity is obliterated, either  owing to  the
 parietes being confounded together or closed by a sort of 
MUCOUS SYSTEM.
225
membrane, or because the canal itself has entirely disap-
peared.   These  canals are sometimes deficient  in a part
of their circumference, which  then exhibits preternatural
openings, fissures and communications ; it  is in  this way
that the vagina is seen opening into the rectum;  the blad-
der, destitute of its anterior parietes, communicating with
the hypogastric  region,  which is itself destitute  of parie-
tes  ; the urethra opening into the  perineum ; the palate
establishing a communication between the mouth and the
nasal fossae, the velum pendulum  separated in its middle,
the lips divided  as in hare-lip, &c.  These alterations are
often only the remains of an unfinished, natural  develop-
ment ;  this is evident in  the hare-lip, the  extroversion
of the bladder, &c.
  We should not forget, in the anomalies of development
of  the  mucous  system, the  digitiform  elongations or
digital  appendices of the intestine.  These elongations
are formed by all  its membranes ; we  have seen  above
the attempt that has been made to explain the mechanism
of  their formation.   There is sometimes found, towards
the point of junction of the pharynx  and the oesophagus,
similar appendices which retain the aliments, which  occa-
sions a sort of  rumination ; these appear to be  consecu-
tive and formed by a hernia of the mucous membrane
across the  fibres  of the  nervous  coat.   Calculi of the
bladder are often lodged in cavities produced by the same
mechanism.
   We may consider as  preternatural  mucous membranes,
 1st, the membrane which  lines the interior of abscesses ;
2d, that of old fistulous canals.
   The membrane of abscesses, though belonging to cavi-
ties closed on all sides, has in fact  more  points of resem-
blance  to the  mucous than  to  the  serous  membranes ;
follicles, it is true, have not been described in it; but its
                29 
226      ADDITIONS TO THE MUCOUS SYSTEM.

surface is soft, pulpy and fungous, like that of the mUcous
membranes;  when put in water,  it seems, like these last,
to be covered with filaments.   The  analogy of  seeretion
is an  additional reason  in  favour  of this  resemblance;
wdiat is more analogous to mucus than pus ?
  The resemblance is still more evident in sinuses and fis-
tulas terminating on the  exterior.   Hunter had already
noticed this resemblance, upon which Bayle, Laennec and
others  haA^e more particularly insisted.  The membrane of
the fistulous canals has a distinct  epidermis  in the neigh-
bourhood of the skin ;  farther in, it disappears, and the
membrane  becomes  red, soft and fungous ;  it would  be
difficult, in this place, to distinguish  it from a portion  of
mucous membrane taken from the sinuses, for example ; it
has no follicles, but its  fluid  is almost of the same nature;
below  it, the eellular texture is often hardened  and more
compact than in the natural state, as  is seen  in callosities ;
it is a result of inflammation ; this texture is sound when
the inflammation is slight.  When  every thing  ceases to
pass through  the fistula, it contracts  and its canal closes ;
it differs in this from the mucous  ducts, which are not ob-
literated under the same  circumstances ; but its oblitera-
tion is not always  easy, especially in the neighbourhood
of the skin, and in general fistulous  canals have but little
tendency to cicatrization ;  thus  we  endeavour by every
method to develop inflammation in them  or to destroy
the membrane which covers them.
   In abscesses, as in fistulas, the  preternatural membrane
derives its origin from the cellular texture, and is owing
probably to an albuminous exudation of the nature of that
which constitutes false membranes. 
ADDITIONS
SEROUS  SYSTEM.
      MORBID  ANATOMY OF THE SEROUS SYSTEM.

  The alterations of this system  have been already in
part  pointed  out  by Bichat;  the following is what we
shall add to what he has said of them.

        I. Alterations in the External Forms.

  Sometimes the  serous membranes thicken at the  same
time that they are increased  in extent, as  is seen  espe-
cially in hernias and dropsies ; this increase in all  direc-
tions supposes a real  increase of nutrition  in them ; this
cause then should be added to all those which facilitate
the extension of these membranes, as their  displacement, 
228               ADDITIONS TO THE

the disappearance of their folds  and their peculiar exten-
sibility.   (See  in the Serous  System the article  Exten-
sibility.)   In other cases, the thickness of these  mem-
branes is  so much  diminished by distension, that often-
times they are found  with difficulty.   This is not  rare
in umbilical hernia.
   The serous system is  subject  to various displacements,
which alter  more  or  less its configuration.  These dis-
placements are  most often only secondary, and are owing
to changes that  take  place  in the viscera which this
system  covers, or in the parietes of the cavities which
contain  these  viscera,  parietes upon  which it  is also
spread; they are  consequently of  the  same nature  as
those which the various functions produce  in the natural
order.  Now these displacements  take place in  three
ways; 1st, the serous membrane  leaves the parietes and
goes  upon the viscera ; 2d, it  leaves these last to go
upon the first; 3d, it extends without the parietes, forms
a sac, which is united  to  the general sac  that it forms
within; this sac is constituted by the portion that lines
the parietes; but in time the membrane is  also detached
from the viscera, or draws  them out when it adheres  to
them too strongly.   The sac  of which  we are speaking
is  produced whenever a viscus,  forced  through the pari-
etes  of its  cavity, carries at the same  time before it the
serous coA^ering of these parietes ; this is the sac of  her-
nias, the hernial sac properly  so  called.  But in  some
cases, this  sac exists  previous  to  the  hernia, and the
viscera  are not connected with  it till afterwards ; this is
what takes place when fat accumulates on the exterior of
the peritoneum for example, and finally forms a mass, the
situation and weight  of which  draw   it outwards, and
which also  draws the serous membrane with it,  so that
this  forms a  sac ready to receive  the viscera on the first 
SEROUS SYSTEM.
229
occasion ;  an arrangement very  improperly knoAvn  by
the name of fatty hernia.   It is important to  know in
practice the displacements of the serous membranes,  be-
cause they often change the relation of the parts ; the  sac
of hernias, in particular, presents many points for study.

         II. Alterations in the Organization.

   The  most of those Avhich are the  consequence  of
inflammation depend on changes which are experienced
by the fluids that are naturally exhaled in the serous cavi-
ties, changes Avhich vary according as  the inflammation
is acute  or  chronic.  These fluids  may be  simply  in-
creased in quantity, and preserve all  the qualities of  the
serous fluids, or  they  may  be altered in various Avays ;
from  this  simple serum to  opake pus, destitute  of glo-
bules like that of the cellular  texture, there is an infinity
of gradations.   Most often a matter capable of concretion
is produced, either albuminous flakes swim  in the effused
fluid, or a layer of  the same nature,  a false membrane,
distinct from this fluid, covers the  inflamed serous mem-
brane, or  this layer, interposed between the two folds of
the serous membrane not separated  by an intermediate
fluid, establishes between them an  adhesion, soft and  glu-
tinous, similar to what  is formed  between the lips of a
wound united  by the first intention.   The false mem-
branes  begin by insulated points of  albuminous  matter,
deposited at first only in the most inflamed places, after-
wards united together,  and then  forming  a continuous
layer, the thickness and consistence of which vary. This
layer  adheres but slightly to the membrane  which  fur-
nished it;  but there is observed,  when it is  detached from
it, that a sort of indentations, reciprocal inequalities unite
one to the other ; under it, the serous membrane is usually 
230
ADDITIONS TO THE
red and penetrated Avith vessels.  From  the  production
of these false membranes, and from the soft and skin-like
adhesion which is but a slight modification of them since
it only differs from  them by the absence of  a fluid  suit-
able to maintain the separation of the folds of the serous
membrane, are derived all  secondary effects of inflamma-
tion, both acute and chronic, all the varieties  of thicken-
ing and all the modes of adhesion.  The  albuminous or
skin-like matter of the false membranes, Avhich thickens,
hardens, is organized and  penetrated with vessels, occa-
sions these varieties, by  the  variable forms it assumes at
the moment it experiences these changes; we shall not
revert to the manner in which  they take  place; the de-
velopment of the vessels,  which is the main point, has
been  examined in the  capillary system.   We may now
understand  how miliary  granulations,  opake, whitish,
sometimes extensive and supported by a narrow  pedicle,
cover  the serous membranes  after their inflammation,
the evident result of the concretion of albumen on  their
surface ; how layers of the same nature  are  seen, under
the same  circumstances,  upon the pericardium, the arach-
noides, the  tunica  vaginalis,  &c.;  how  these different
membranes, the pleura and peritoneum in particular, often
acquire in chronic  inflammation,  a  thickness double or
treble  that  Avhich they before exhibited ;  a thickness
which is only owing to the presence of the false mem-
branes organized and intimately united  Avith these mem-
branes, and  which should  be distinguished  from  that
which  is owing to a real increase of nutrition ; how the
cellular  and filamentary adhesions arise, those  in Avhich
the  two folds of the  membrane are  entirely confounded.
and the filaments, &.c. according as the albuminous matter
is stretched a little or not at all, or as on the  contrary,
this matter has been subjected  by  the motions of the part 
SEROUS SYSTEM.
231
to frequent distensions, according as the inflammation
has continued for a  longer  or shorter time and  the or-
ganization has been more or less perfect,  &c. &c.
  A cicatrix  arises from the serous system Avhen divided,
though it was doubted for a long time.   It is linear and
afterwards  imperceptible Avhen the edges of the wound
have remained in contact, and it is a  cellular  membrane
analogous to the texture whose place it supplies when these
edges have not been properly brought together; we may
be convinced of this fact by examining the pleura of an
animal Avhich had been  opened some time before.   Thus,
in the hernias which succeed  to the old Avounds that pene-
trate the abdomen, the  peritoneum forms, as usual, a sac
for the displaced viscera, though  the contrary has been
for a long time maintained ;  only this sac is more delicate
and seems  to be entirely formed  by the  cicatrix  which
remains more extensible than the neighbouring texture.
  The serous membranes are ossified ; no one is  exempt
from this  alteration, which  appears under many forms.
They are usually plates appearing  rather  to raise  up  the
membrane  than  to  belong  to it  ; sometimes, however,
these  plates  are almost  naked on  the  interior of this
membrane.   The  tunica  Aaginalis, the  pleura  and  the
peritoneum contain also, in  some cases, a species of con-
cretions similar  to those of which  the synovial system is
the seat, and  to  which we shall revert.
   M.  Laennec has described, in his treatise  upon  Aus-
cultation  Mediate, tumours of  the pleura  Avhich he
refers  to  the cerebriform cancer; they occupy  the in-
ternal  face of this  membrane, to  which  they adhere
strongly ; their  environs are  marked by a slight  redness
owing to  the development  of the  blood  vessels ;  tbey
are usually in  small  number.   There is often found, in
intestinal ulcerations, particularly those Avhich take place 
232
ADDITIONS TO THE
 in phthisical patients, small miliary tubercles Avhich make
 a part of the serous membrane at the place of these ulcer-
 ations.   Various  authors  have spoken of schirri of the
 serous membranes ; but they no doubt intended to desig-
 nate by this name thickenings, the result of inflammation,
 and not a true degeneration.


         III. Alterations in the Development.

   The defects of conformation are quite rare in the  sys-
 tem of which  we are  treating.   The peritoneum,  the
 pleura and the pericardium, instead of  representing a sac
 without an  opening, are sometimes open  in  front, and
■are destitute of the exterior  lamina to a certain extent,
 so  that their viscera  are bare.  The arachnoides has  a
 very imperfect organization in the  aencephalous foetuses;
 but this defect is but  a  consequence of that which then
 exists  in  the brain.   The peritoneum has exhibited, in
 some rare cases, a sort of vesicle or secondary  sac situ-
 ated in its  interior,  communicating  with  it  by a  nar-
 row opening and containing a part  of  the abdominal
 viscera.
  Bichat was the first Avho satisfactorily proved the anal-
ogy Avhich exists  between the cysts that are  preturnatu-
rally formed in various parts of the body and  the serous
membranes.  (See  the Cellular  System, Vol.  1st, and
the Serous System, Vol. 3d.)   He has refuted the opinion
of Louis upon the mode of origin  of  these cysts, which
he regards as always existing  prior to the substances they
contain.   It is  necessary however  to  make a  distinction
here ;  in  fact, 1st, there are cysts that are  really pre-
existent, as  all those that are  called meliceris, atheroma
and  steatoma ; but  these are only  sebaceous follicles 
SEROUS SYSTEM.                  233
exceedingly dilated, as Ave  shall  see in another place ;
(Vide the Dermoid System ;)  the cysts of the ovarium
are perhaps  also in the same situation, as the3r appear  to
be  owing only  to  preexisting vesicles ;  2d,  there are
evidently consecutiAre ones, Avhich are formed around
various  bodies coming from without, around  the  blood
in apoplexy and pus in chronic abscesses ;  3d,  the origin
of a great number  is obscure, to Avhich the observations
offered by Bichat apply perfectly.
   On the other hand, the organization of cysts is far from
being the same, though  in general they belong to the
serous system.  Some are  soft and  almost  fluid,  as it
were; it seems as if they Avere  the result of a simple
exudation ;  some of  this species have been found in the
brain.   At other times it is a membrane but  little differ-
ent from the cellular texture; in some cases, on the con-
trary, it is  a real  serous cavity, very distinct from this
texture, as is seen on  the neck, and in the spermatic cord.
There are  some, the  structure of which  resembles that
of the mucous membranes ; others have a slight resem-
blance to the skin.  These cysts are moreover susceptible
of various  transformations ; they  become  fibrous,  carti-
laginous and osseous ; the cancerous and other degenera-
tions are also met with in them.
   The substances contained  in  these preternatural sacs
are infinitely various.  Solid, foreign  bodies, blood, lim-
pid serum,  viscid,  gelatinous or  mucous  matter, serous
fluids mixed with  albumen  that is capable of concretion
and that Avhich is  not, fatty fluid  matters,  or those with
different degrees of consistence,  a pultaceous,  stony  or
cretaceous substance,  and concretions more or less  hard
may be  contained in  them.   Authors have  been  much
engaged in explaining these differences, which are  often
observed in cysts that are analogous in structure.   They
              30 
234               ADDITIONS TO THE
have been in general attributed to causes purely mechan-
ical.  It is  thus that Bostock,  who  has  examined the
matter of many cysts found in the  interior of the pelvds,
after having praised  Cullen for  rejecting  these explana-
tions, proposes himself one of  this kind, by which, ac-
cording to the state of the heart and the modifications
which  result from it in  its  action, according to  those
Avhich  the animal heat experiences  or the  disposition of
the small vessels, there would  pass through these  last,
sometimes the serum of the  blood almost  pure,  some-
times  this serum, with  a proportion of albumen, either
in a fluid  or concrete state, sometimes these two matters
united to  fatty matters under Ararious forms, and  all the
substances in fact wdiich are found in cysts.   It is eA'ident
that the mechanism of exhalations is too little knoAvn, for
these explanations to be accurate ; the  causes mentioned
may no doubt  contribute to the production of the phe-
nomenon, but they assuredly  do not alone constitute it.
   Hydatids resemble cysts  in their  apparent structure,
though they are very different in their nature ;  this is so
true that authors are not often agreed upon  what should be
called cyst and what hydatid.   The following however are
the principal characters by means of which  they are dis-
tinguished ; 1st, cysts are attached to the surrounding parts
by cellular texture and blood  vessels ;  hydatids, on the
contrary, are perfectly free ;  it is true, that in some cases
cysts are  found hardly adherent; but these cases are rare.
2d. The  parietes of the cyst  have always more or less
consistence; the hydatid  has only that of the  Avhite of
an egg boiled.  3d. The hydatid often  exhibits in some
point of  its  surface, something  like  little grains  Avhich
are discoverable  by the naked  eye or Avith a glass, and
which  seem  to  be  the   rudiments of other hydatids ;
nothing similar is seen in cysts.  Notwithstanding these 
                    SEROUS SYSTEM.                235

differences,  Avhich  are striking,  there  are  cases  where
it is difficult to decide, to which kind of productions they
belong ;  this is almost always the  case, for example, in
the vesicles of the  plexus  choroides, and still  more  in
the masses  of the  same kind which are situated  in  the
placenta, and  the nature of  which  is  still very doubt-
ful. 
 
ADDITIONS
TO THE
SYNOVIAL SYSTEM.
            Of the Synovial Membranes.

  Page 179.—" From these different considerations we
may be easily convinced, I think, that  notwithstanding
the adhesion of the synovial membrane at different points,
it should be considered  ...  as a real  sac Avithout an
opening, everywhere continuous  and spread upon all  the
organs of the articulation."

  The reality of this arrangement, already recognized by
Nesbith, Bonn  and Hunter, and  which  some persons
have doubted, is also proved by the following considera-
tions. 
238
ADDITIONS TO THE
   1st.  In inflammation of the synovial membrane,  the
redness, beginning on the free portion of this membrane,
extends  gradually  from the  side  of the cartilage,  the
surface of which it finally reaches, nearly  as  in ophthal-
mia, the conjunctiva  reddens gradually upon  the globe
of the  eye,  according as  it  is near  the  centre of the
cornea.  This gradation is easily observed  in dogs, in an
articulation that is  opened, and the interior of Avhich is
left in  contact  with the air.   The redness, in this ex-
periment, never reaches the substance of  the cartilage ;
it  is  confined to its  surface, and  is, as it were,  foreign
to it.
   2d.  There is a continuity of vessels between the kind
of capsule which the membrane forms  around the  osseous
surfaces, and the surface of the cartilage, as is evidently
seen in the preceding experiment.  The synovial mem-
brane of the  knee, injected in this way, exhibits, in its
adipose ligament,  vessels  which  extend  directly in  its
portion Avhich covers its cartilage,  to the two extremities
of this ligament.
   3d.  If a bone be divided  perpendicularly at its articu-
lar extremity, by leaving  untouched the cartilage of this
extremity, and if,  by the separation of the two halves of
the bone, the cartilage  be  afterwards ruptured, the  tAvo
fragments still  hold together by the synovial  membrane
which  passes  from one to the other.  It is the same
when the surface of a cartilage is  broken, and the piece
raised  up, so as  to  break  it  at its  base ; this  piece  still
adheres by means of the synovial  membrane, which has
not been ruptured.
   Let  us conclude from  these  different facts, that the
synovial membranes, far from being limited to the circum-
ference of the articulations, go to the whole extent of the
osseous surfaces, upon the  cartilages  which  cover these 
SYNOVIAL SYSTEM.
239
surfaces, and really constitute sacs wdthout an opening, in
every respect  similar to those of the serous membranes,
as has been very well seen by Bichat.

                  Synovial  Fringes.

  Page 181.—" If  a remarkable redness sometimes
distinguishes these  bunches" (the  pretended glands of
Havers) " from the  cellular texture, it is because the ves-
sels  are more concentrated and nearer together in them.
This redness of some pretended synovial glands, the only
character  that distinguishes  them, is  then as it  were
merely  accidental;  it no more  indicates their  glandular
nature,  than it proves it in the pia-mater,  in which it is
owing to the same cause."

  What is here said of the fatty bunches  so improperly
called glands of Havers, may be also said of the synovial
fringes  which surmount  these bunches, and the vascular
structure of which does not prove that they are excretory
ducts.   These fringes, very well described and drawn by
Monro, are folds of the synovial  membrane  floating in
the articulation, and precisely analogous, in this respect,
to the epiploons of the serous  membranes, and the epi-
ploic appendices  of the intestines.   These  folds  are
grooved on  their  surface, have their  free edge  cut in
various Avays, as can be very well   seen by floating them
in water, and resemble in some measure fringes ; hence
the name that has been gi\ren to them, and which may be
retained, though it  by no means expresses their nature.
Between  the  two  laminae of these  folds, and  in  these
laminae themselves, there is a great number of A'essels,
arteries, veins, exhalants,  and no doubt absorbents  also ;
thus the synovial membrane is much redder there than 
240
ADDITIONS TO THE
any where else.  It is to the presence of these vessels, the
exhalants in particular, that the following phenomenon is
owing, Avhich may have deceived Havers;  if  these folds
are pressed, synovia oozes out of them,  which evidently
comes from the open exhalant orifices, and not from par-
ticular ducts.
  All the  synovial membranes have  these elongations,
both those which belong to the tendons and those destined
to the articulations, although  they are more  evident  in
the last  than in the first; among these, those in the form
of vesicles have them more constantly than  those in the
form of sheaths.   The great articulations, as those of the
knee and the hip, contain the largest; in the small ones
they are often only reddish points slightly  prominent.
They are  in general situated  near the place  where the
synovial membrane is reflected around the articular carti-
lage, and  usually  correspond  to the adipose  texture  of
the synovial bunches, in part contained in their substance;
those of the tendinous  synoAdal membranes  have  often
between their laminae, instead of this texture,  soft bodies
like gelatine, the fatty bunches analogous to the articular
ones called glands  of Havers being Avanting in many of
these membranes.
  The synovial fringes,  from the great number of vessels
they contain, are the especial seat  of the secretion  of
synovia.   This secretion is perspiratory, and evidently of
the class of exhalations; it only takes  place there more
than in  any  other point of the  membrane, because the
exhalants  are more  numerous there.
   The following  is the idea that  should be  formed  of
synovial fringes  and bunches;  1st, blood vessels  sur-
rounded  with a more or less  abundant  adipose and cel-
lular  texture ; 2d, folds,  which  embrace them and  in
Avhich they particularly terminate ;  folds  more or less 
                 SYNOVIAL SYSTEM.               241

numerous,  more or  less extensive,  and  whose surface
pours out synovia in  abundance.
  The  mucous  system exhibits  something analogous  to
the fringes of the synovial membranes in the folds which
exist under the tongue, and upon the sides of the frenum
of this  organ; these  folds are real secretory  fringes, de-
signed  to increase the extent of the exhalant system.

Parallel  between the Synovial Membranes  and  the
           Serous ones properly so called.

   Page 181.—" Though the synovial membrane is very
analogous  to the serous surfaces, it must however exhibit
differences of texture, since the  fluid  it exhales is  a little
different.   Its texture  has  not  the suppleness of theirs.
It resists maceration longer."

   The synovial membranes might justly be called  the
serous membranes of the articulations and the tendons ,
yet the difference of the parts  Avhich they invest gives
them peculiar characters.  Most of these characters have
been stated ; the following  are some more of them.
   The synovial membranes receive  fewer sanguineous
and other vessels, than the serous  membranes.   These
appear, as it were, to  be  entirely formed  of vessels in
inflammation,  after  fine injections,  &c. ;  the  synovial
membranes contain much fewer  under like circumstances.
Compare  the  deep  tinge of the serous membranes  in
asphyxia with the much less evident one of the synovial
membranes in the same case, and you will be  struck with
this difference.  The lymphatics are in  immense  quan-
tity in the serous membranes, as is shown by injections ;
Ave admit  them from  analogy, and  only on  account  of
their functions, in the synovial  membranes.
              31 
242
ADDITIONS TO THE
   Maceration  discovers  in  these distinct  laminae  and
 fibres ;  the serous membranes have them also, but theirs
 are much less apparent.
   The synovial membranes, especially those of the artic-
 ulations, are  less extensible,  and seem to be torn sooner
 than the serous ones; at least ruptures are more frequent
 in them  than in the latter.   This difference is owing per-
 haps solely, or in great measure, to this, that the connex-
 ions of  the membranes  are not the same, any more than
 the causes which distend them ; the  one  fixed  to  the
 bones, and strongly draAvn  by  these organs, must yield
 and break, as happens in luxations, the  others, in relation
 with the soft parts and capable of yielding themselves,
 are merely elongated, as is seen  in hernias.

 Existence, For?ns,  Organization, fyc. of the Synovial
               System of the  Tendons.

  Page  191.—" There  are many synovial membranes the
existence of which is variable ; such as, for example, that
of the great glutaeus, in the  place of Avhich there is often
found only a cellular mass."

  In this respect,  \\z. that some parts of this system are
sometimes wanting and  are then replaced by  cellular tex-
ture, the  synovial system of the tendons is  confounded,
more perhaps than the  serous and the articular synovial,
with the  cellular.   But,  besides the latter resembles  in
many places,  in its  arrangement, the  mucous bursae  or
synovial   membranes  of the  tendons.   Wherever  great
motions  take place,  the cellular texture is loose, lamel-
lated and filled  Avith fluids ;  its  laminae are separated by
broad interstices, imitating more or less exactly the  cav-
ity of the serous or synovial  membranes, so  that it may 
SYNOVIAL SYSTEM.
243
truly be  said, that  these  membranes exist  in  rudiment
Avherever there is this kind of motions.  This is Avhat is
seen on the thigh,  between the tendon  of the  anterior
rectus and that of the  triceps, between the biceps and the
anterior  brachialis on the arm, &c.   There is a sort of
gradation according to the mobility of the parts, in this
arrangement of the cellular texture;  the integuments  of
the back of the hand, those Avhich  cover the anterior face
of the patella, the  olecranon and  acromion have  under
them, on account of their frequent sliding, a cellular tex-
ture which resembles that which is found around the ten-
dons, sometimes even true mucous bursae.   Finally, where
the frictions  are  very evident, as between the tendons
and the bones, these are nearly constant.  They are found
almost uniformly, with a  greater or less degree  of devel-
opment,  betAveen the skin and  the bones, in  the  places
Avhere these parts have frequent motions, as at the elbow
and the knee, so that in those places  there are generally
sub-cutaneous mucous bursae, as there are tendinous ones.
  There is a circumstance which  may also have an in-
fluence upon the existence and  number of the tendinous
synovial membranes ; it is that some are sometimes in-
sulated,  and  sometimes confounded, as is  seen  in  those
Avhich line  the sheaths of the tendons,  according as these
sheaths  are themselves separated or confounded together.
  In order to see these membranes well when they exist,
Ave raise the tendon below Avhich they are to  be found,
open them to a small  extent, and force into this opening
air or the matter of injection ; they are distended  and then
become very apparent, and distinct from  the surrounding
cellular   texture; or  we  may be  content  with  opening
them with  care ; the moisture and  polish of their surface
serve to distinguish them. 
244
ADDITIONS TO THE
   The   tendinous   synovial  membranes  exhibit  some
 differences in  their forms, besides the general  division
 into vesicular  and  vaginal pointed  out  aboATe.   Their
 caATity,  instead of being  simple, is often  multilocular,
 (having many cells,) divided  by elongations  which are
 detached  from  their  interior ;  these  elongations  are
 usually  soft,  but  in some  cases  fibrous.   The vaginal
 mucous bursae  have one of their extremities  divided  in
 the manner of  digitations, when many tendons, united at
 first in  a single sheath, are afterwards separated, &c.
   These membranes have, as we have said, fringes and
 sometimes even   synovial  bunches  on  their  interior.
 Fourcroy and Koch have seen villi in them.   The vesi-
 cular synovial  membranes are  of a texture more  dense
 and compact  than the vaginal, and nearly fibrous in some
 points.
   Their fluid is yellowish, sometimes reddish ; but then
 this  tinge  is accidental,  and generally a result of  the
 transudation which takes place after death.   It appears to
 be thinner in the synovial membranes of small extent,
 and  which  do  not experience  considerable  frictions ;
 thicker  and  more viscid  in  the others, in that Avhich
 covers  the  great  trochanter,  for  example, and  Avhose
motions are  very  evident.   This  fluid  has  not  been
analyzed ; it  appears to  be  formed  of Avater, albumen,
soda and perhaps some salts ; it is  miscible with Avater
 in any  proportion ;  heat  and the acids coagulate it; it
 turns the syrup of violets green ; Avhen dried, it is trans-
 formed  into  a  kind of horny  lamina, very  thin, which
 burns like the dried white of an egg.
   The mucous bursae are A'ery extensible, as is seen Avhen
they arc inflated ; dropsy also furnishes a proof of it.
 They contract when the distension is removed. 
SYNOVIAL SYSTEM.
245
    MORBID  ANATOMY OF  THE  SYNOVIAL  SYSTEM.

        I. Alterations in the External Forms.

  The distension of the articular synovial membranes by
a collection of synovia constitutes hydarthrosis, an affec-
tion that is not common and which is observed especially
in the knee, which, in general, presents the most frequent
examples of all the diseases  of  the  articulations.   The
quantity of the  accumulated fluid ATaries, as well  as  the
nature of this  fluid ;  this  is dependant on the various
complications that may exist, as  on inflammation in par-
ticular.   The distension is  usually more eAudent in  one
or several points, where the  synovial  membrane is  the
least supported by the surrounding parts.
  Dropsy of the mucous bursae is  called hygroma when
its fluid  is serous, colourless  and  limpid, and ganglion
Avhen it is a  reddish, thick and  viscid matter, more  or
less similar to currant  jelly.  Neither always have their
seat in  the  natural  mucous bursae ;  they are  sometimes
preternatural tumours, a sort of cysts.   It is thus that the
ganglions are formed upon the  back of the  hand though
there are no  mucous bursae in this place.   The hygroma
is frequent in front of the  patella, on  the  shoulder  and
the elbow, places where the cellular texture is  so closely
connected with the synovial  membranes ; it takes place
especially in  persons who have  these parts subjected to
constant pressure.
  Anchylosis exhibits, as is known,  many varieties.   In
that which is called false and which should  be considered
a distinct disease, all the parts which enter into the com-
position of the articulation are thickened.  But  anchylosis 
046               ADDITIONS TO THE

properly so called, affects especially the  synovial mem-
brane.  Sometimes filaments of various extent and  con-
sistence traverse the articulation, and unite the two oppo-
site laminae of this membrane which covers the  articular
surfaces ;  a sort of amphiarthrosis then exists;  an articu-
lation Avith limited motion and with  continuous  surfaces
takes the place  of the one  which  existed  before  with
great motion and contiguous  surfaces ; it  is  to  this first
variety that the name of false anchylosis may be given,
if it be desirable to preserve this distinction.  Sometimes
the adhesion  between  the  two  surfaces  is  intimate, the
synovial membrane disappears or is changed into  cellular
texture, the  bones are united  together  and are finally
deprived  of  the  lamina  of compact substance  which
covered their extremity ; this is true anchylosis.   These
two kinds of adhesion  suppose here, as in the preceding
system, an anterior  inflammation.


         II. Alterations  in  the Organization.

  Besides these adhesions, the inflammation of the syno-
vial membranes sometimes produces ulceration  in them,
though it is  quite rare ;   Mr.  Brodie has  related  two
examples of it.  In other  cases, this inflammation termi-
nates  by resolution, and there results from it only a little
stiffness and embarrassment in the motions, owing to the
thickening of the parts.   It may also be  followed by
suppuration and effusions of various kinds, though  these
effusions are observed  less frequently than in the serous
system.
  The tendinous  synovial membranes exhibit  in their
inflammation, fortunately  quite  rare, the  two modes  of
;»'!heszon  which  have  been  noticed, viz.  filaments and
i 
SYNOVIAL SYSTEM.
*47
 adhesions  properly  so called.  They  also suppurate at
 other times, and then their tendons most usually exfoliate.
   The foreign bodies of  the  articulations,  which  some
 have taken for concretions formed in their  interior, and
 which others  consider as  broken and  detached portions
 of bone  or cartilage, are  always situated in the begin-
 ning, without the synovial membrane.  They are osseous
 or cartilaginous productions deposited at first in the cellu-
 lar texture, pushed afterwards by degrees, either by the
 various motions or  any other cause, into the cavity of
 this  membrane, in Avhich they are enveloped  and Avhich
 they stretch  prodigiously as they adA'ance ; it  terminates
 by forming for them only a  sort of pedicle,  which at
 length becomes thin  and finally breaks  ; when  this  rup-
 ture takes  place, the  body is loose in the articular cavity.
 The state which it  then  exhibits varies ; its  consistence
 is sometimes very soft and like albumen, at others carti-
 laginous or osseous ;  in some cases the same body exhibits
 these different  states.  The long continuance  of these
 bodies and the pressure which they exert, often produce
 upon the  articular  cartilage, depressions  or  cavities in
 which they are lodged ;  these depressions have led to
 the  belief that there AAras a loss of substance of the  car-
 tilage, the detached  fragment of Avhich  produced the
 foreign  body  ;  but   we cannot  conceive  of  any cause
 capable of  producing such a separation, and besides, in-
 spection does not confirm this idea.
  Bodies of another nature are developed in  the mucous
 bursae, and sometimes also in the articular synovial mem-
 branes.   They are  usually extremely numerous, of the
size  of a large apple  seed, flattened in A^arious  directions
and of a whitish colour.  They haAre been thought to be
animated, but  they appear to be  inorganic ; their origin
 is but little   known.  Monro has  also  found  in  the 
248
ADDITIONS TO THE
mucous bursae  small bodies  of a  peculiar nature.  The
same author says that he has met with cartilaginous plates
in them.
   In ivhite swellings, an improper term  under Avhich  is
confounded various degenerations and the chronic inflam-
mation of the synovial membrane, this often becomes the
seat of a  peculiar degeneration ;  its texture  becomes
thickened, greyish, like  lard,  homogeneous and surround-
ed with soft fungi, the  presence of which beneath the in-
teguments may lead to the belief that there is an  abscess
on  account  of  a  kind  of obscure  fluctuation  that   is
thought to be felt there.

         III. Alterations in  the Development.

   The membranes analogous to  the synoAnal  ones that
are  met with  in the  supplementary articulations, the
consequence of luxations not reduced, are in part formed
by the remains of the  old one  that is ruptured  and  in
part by the real production of a new texture.  Fractures
that have not united sometimes haATe a capsule which
seems  also to  belong to the  synovial  system, inasmuch
as it contains a serous fluid, as we have said elsewhere.
  The synovial cysts, which  were mentioned at the be-
ginning of this  article, are preternatural mucous bursae.
  The absence  of some tendinous synovial  membranes,
under  some circumstances, is the  only defect of confor-
mation peculiar to this system. 
ADDITIONS
            TO THE



GLANDULAR* SYSTEM.
          Intimate Structure of the Glands.

  Page 200.—" The glands, like all the other organs, .. .
have their peculiar texture which especially characterizes
them, which belongs only to them, a texture  in  which
the arteries communicate with the veins and the excreto-
ries.  Let us not push our researches further; if we do,
Ave  shall be inevitably entangled in conjectures."

  Is the communication direct between  the arteries and
the excretory ducts, or is there  something intermediate
between these two orders of vessels ? The results obtain-
ed by Ruysh and Malpighi  in the solution of  this ques-
tion, though opposed to each other, are however equally
             32 
250                ADDITIONS TO THE
 founded  upon facts rather than upon mere conjectures.
 Only these two anatomists,  both  alike commendable, no
 doubt directed  their attention to glands wholly different.
 In fact, it is easy to see, by the description even of the
 glandular system, that  the organs which are comprised
 in it, even by restricting  as  much as possible the  term
 glands, and by applying it only to those  to which it ex-
 clusiArely  belongs, by taking  from it  consequently the
 mucous and sebaceous  follicles or glands,  of Avhich A\*e
 have spoken in the article on  the Mucous System, and
 the  glandiform organs, as  the  thymus, the  thyroid, the
 supra-renal capsules, &c. ;  it is easy to see, I  say,  that
 these organs vary in  their most essential properties, and
 have at most  only some  general  points in Avhich  they
 approximate each other.  Thus, as it  regards structure, of
 Avhich we are now to treat, the opinion of Ruysh seems
 to be perfectly applicable  to some of these glands, the
 Jiver, the testicles and the kidneys ; whilst, in respect to
 others,  such as the lobulated or  conglomerated glands in
 general, that of Malpighi has  more probability in its
 favour.  Inspection and experiment may be resorted to ;
 the  one shows us, in the  first of these glands,  an   evi-
 dent vascular arrangement in  all the points of the organ,
 a continuit}' that can be  traced by  the eye, if we may so
 say, between  the sanguineous ramifications and  those of
 the excretories;  in the second, this arrangement is much
 less  distinct and it is impossible to  discover the continuity
 in most cases.   By the other we  see, in  injections, the
 rapid, easy and constant passage, in the excretory Aessels,
 of the matter driven in through  the arteries in one class,
 the liver, kidneys, &c. ;  this same  passage, slow, difficult,
 and oftentimes wanting in the others, as in the salivary  and
 lachrymal glands, pancreas, &c.  It may then be possible
•that  the little grains that are perceived in the latter  may 
GLANDULAR SYSTEM.
251
be small bodies  intermediate between the arteries, veins
and excretories, as Malpighi  thought, species of follicles
in which the one terminate and from which the others go
off; whilst every thing may be vascular, according to the
hypothesis of Ruysh,  in  the glands of the other kind.
Hence no  doubt why the bloody excretions  are very
much more  frequent in the latter, especially in the  kid-
ney, than in the first.


 Influence  of Nerves upon the Action of the Glands.

  Page 223.—" If we weigh the proofs given by Bordeu
of the influence of the  nerves on secretions, we shall see,
that  they either rest upon false  facts,  like those of the
section of the nerATe, of sleep, &c. or upon vague data."

  Every thing which relates  to the peculiar action of the
glands is in general but very little known, as is the  case
Avith all the phenomena which take place in the interior
of the organs.   All that is known upon those of glandular
secretion is  confined nearly to this ;  blood containing the
materials of secretion arrives in the glands by the arteries,
except in the liver, which receives it from  the  veins and
the arteries; this blood, in traversing the glands,  under-
goes  changes in them in consequence of Avhich a  fluid
wholly  different from it  is  produced.  But do these
changes take place suddenly,  or slowly and as the blood
adA'ances  in its course, and  what  is their nature ?  Are
they merely the result of the  configuration of the parts
and  a phenomenon purely mechanical  ? Is it a chemical
or galvanic action which produces  them, a doctrine which
seems to prevail at the present day in many schools ?  Is
it  a consequence of the  nervous influence, or finally do 
252
ADDITIONS TO THE
all these causes contribute to it at once ? This is Avhat we
are ignorant of.
  As to this  last influence, that of the nerves in  secre-
tions, it is probable that it  exists, as Bichat says, though
it may be very difficult to be  certain of it directly.   The
division of all  the nerves of a gland, suggested by Bordeu,
is almost everywhere  impracticable.   The experiments
related  by Bichat will no doubt be found far from being
conclusive  The  following, which  are perhaps  scarcely
any more so,  but in which  however the  results seem to
be a little more  decisive, and  which besides appear to be
so  much the  more remarkable, as  they are in evident
contradiction to the first, are made by Mr. Brodie.
  1st.  The brain having been removed, respiration being
supported artificially, that the  circulation might not  stop
and that the animal might continue to live,  the urine  Avas
no longer secreted.  This fact does not prove positively,
it is true, that the cerebral  action has  an influence upon
the function which the kidney has of secreting urine ; for
it might be that the circulation Avas weakened in this  case
so as to  render the secretion less active ;  it is  however a
strong presumptive evidence of this  influence.
  2d. In order to be able to appreciate the mode of influ-
ence of the nerves of  the eighth pair  upon the mucous
secretion of the internal coat of the stomach, a secretion
not sufficiently abundant in  the natural state to enable us
to obtain striking results, it has been attempted to increase
the products   of it by giving to an animal arsenic  and
other poisonous  substances of the  class  of corrosive
poisons, which produce, among other phenomena,  an ac-
cumulation of the  mucous and other  fluids  that  are  con-
stantly poured out on the  internal coat of  the stomach;
the nerves of the eighth pair have afterwards been  divid-
ed.   At the death of  the  animal, that mass  of fluids is 
GLANDULAR SYSTEM.             253
not found, which  is never wanting under any other cir-
cumstance.  It seems to follow from this that the integ-
rity of these nerves i6  necessary to enable the  mucous
glands or follicles of the stomach to answer to the stimuli
which are directly applied to them.
    MORBID ANATOMY OF THE GLANDULAR SYSTEM.

  The extreme diversity that exists in this system makes
it almost impossible to describe in a general  manner the
morbid alterations  of the  glands ; there  are too many
peculiarities belonging  to the descriptive anatomy,  and
too few  common  points; it would require almost  as
many divisions as there are organs comprehended under
the name of glands ; it is  the  same with regard to the
description of this texture considered in the natural state :
Avhat  Ave shall  now say will be a proof of it.

        I. Alterations in the External Forms.

  Increase of size  as well as the  circumstances under
which it takes place, have  been  noticed (Bichat, vol.
3d,) in the glands that are in pairs ;  the glands  that are
not in pairs, like the  liver, rarely experience it,  without
it  is joined with an alteration of texture.
  Atrophy  comes on in two ways, viz. 1st, from  com-
pression, as from an external  pressure long continued,  or
Avhen a tumour has  gradually destroyed  the interior of
an organ ;  2d,  from want of exercise, as  takes place  in
certain glands from the progress of age. 
 054               ADDITIONS TO THE

   We know all the varieties of consistence, and all  the
 differences of colour Avhich the liver exhibits in diseases.
 The testicle and the kidney also present  some of them;
 the other glands are  much less subject  to this  kind of
 alteration.
   Displacements  are  observed in  those of these  organs
 situated  in the abdominal  cavity, some of them,  as  the
 spleen, can be drawn from  their place in hernias.

          II.  Alterations in the Organization.

   Inflammation  of the glands affects those rather with a
 dense and compact texture, than the granulated ones ;  yet
 the breast is  particularly disposed to it.  Besides, it is
 necessary to  distinguish  this  inflammation from that of
 the  cellular   texture  and  the neighbouring  lymphatic
 glands, this  is important especially Avith regard to  the
 parotid, which is often thought to be inflamed, whilst its
 texture is sound and the cellular texture which surrounds
 it is alone affected.  This inflammation rarely terminates
 in gangrene;  on the contrary,  suppuration and induration
 are the frequent consequences  of it.
  Some  glands, placed on the exterior,  Avhen  compre-
 hended in Avounds, become  the base of a cellular cicatrix ;
 but. the glandular texture  is not reproduced.
  The extreme frequency of  transformations of every
 kind, in the system of Avhich Ave are treating, has already
 arrested the attention of Bichat. (Vol.  3d.)  Yet it is still
 necessary to   establish a  distinction  in  this  respect; in
 fact, 1st,  most of these transformations have been observ-
 ed in the liA'er, the  kidney, the testicle and  the mamma,
 whether  they are  formed of textures  analogous  to  those
which  exist in a natural state, or whether textures wholly
foreign to the economy, except in a state of disease, con- 
                  GLANDULAR SYSTEM.             255

 stitute them ; 2d, who does not know, on the contrary,
 how rare they are in  the  lachrymal and salivary glands,
 and even, to a certain extent, in the pancreas ?

         III. Alterations in the Development.

   Notwithstanding  the numerous  irregularities  in the
 forms of the glands, we must not however take literally
 what has been said  (Vol.  3d.) of the frequency of these
 irregularities, compared with their rareness in the organs
 of animal life.  The difference is by no means so striking
 as  Bichat  has pretended ; Ave  have seen elseAvhere that
 the brain has not always precisely the same conformation
 in  its two  hemispheres, and that Bichat was himself a
 proof of it; his cranium exhibited in fact this singularity,
 that the  forehead Avas much more prominent on the  right
 than  on  the left, and that an opposite arrangement exist-
 ed  at the occiput, whence there resulted an inequality of
 size,  at  the right and the left, in the  anterior and pos-
 terior lobes of the brain.   The bones, muscles and nerves
 exhibit   analogous  varieties.   On  the  other hand, the
 glands are  by no means so variable that this Avould fur-
 nish a character  sufficient to distinguish them  from the
 preceding organs.   Their varieties are often insignificant;
 as in a bone, a groove, a vascular foramen or a depression
 for a tendon have not always precisely the same position,
 extent and  direction;  so in a muscle, the length o  ihe
 fleshy fibres, the  extent of the tendon,  the situation  and
 number of the intersections, &c. vary ad infinitum, and it
is of but  little consequence in a gland, whether a lobe be
a little larger, an edge  more or less hollowed out,  an ex-
tremity more or less extended, &c.
  Besides,  the glandular forms are more or less constant
according to  the  organs in Avhich  they are examined, 
256   ADDITIONS TO THE GLANDULAR SYSTEM.

The kidney alone exhibits almost as many varieties as all
the other glands together; sometimes by itself or united
to that of the opposite side,  sometimes  divided  as in
the foetus into many lobes, sometimes situated in the pel-
vis or  in front of the vertebral  column, there are but few
subjects in which it is perfectly similar.  The liver, the
salivary and  lachrymal glands, &c. exhibit less of these
.differences.
   The glandular  texture  is never  preternaturally pro-
duced. 
ADDITIONS
TO THE
DERMOID SYSTEM
    Colouring Matter.—Mucous Body.—Papillse.

  Page 273.—" It  is necessary to  distinguish two por-
tions  in  the capillary system exterior to the chorion.
1st. One is constantly filled with the colouring substance
of the skin.   2d.  The second is  constantly pervaded by
many fluids.   These two portions  are  entirely indepen-
dent,  and have probably no kind of communication."

  The colouring matter of the skin forms, in the negro, a
layer distinct, not only from the chorion  and the epidermis,
in which Riolan thought it placed, but also from the other
parts  of  the mucous body, with  which  Malpighi con-
founded it.  This matter exists also, though less apparent,
jn the Avhites Avho, without it, would not  differ from
              33 
258
ADDITIONS TO THE
albinos,  who are  entirely destitute of it.  The mucous
body, Avhich Malpighi  regarded as a mere coat, a sort
of varnish covering the papillae, a varnish for which Bi-
chat has  substituted a reticular  body,  essentially formed
of vessels, and divided  into two portions independent of
each other, appears in fact to  contain many distinct parts
observed in the skin of  the negro by M.  Gaultier, and in
that of quadrupeds by M. Dutrochet.
  If the skin of the heel  of a negro  be cut, a little
obliquely as to the  substance  and transversely  to  the
direction of the lines which the papillae represent, there is
distinguished upon the divided edge the following objects;
1st, immediately above  the papillae, and making a part of
them, there  is found a  series of small vascular fasciculi,
designated by M. Gaultier by the name  of sanguineous
bunches.   2d.  Between these  bunches  and the epider-
mis, is seen a black undulating line, placed between two
white lines, one of which separates  it from the first layer,
and  forms  the  deep-seated,  tvhitish  layer, composed,
according  to M.  Gaultier,  of white vessels.   3d. The
black line Avhich is  above, or the  coloured layer, takes
the name  of gemmule,  on account of its  undulations,
which make it appear as if composed  of an infinity of
small concave bodies embracing the summit of the papil-
lae ; each of these small bodies receives two sanguineous
bunches, the summit of the papillae being bifurcated, as
Ave shall say hereafter.   4th. Finally, immediately beloAv
the epidermis is the second colourless layer, or the super-
ficial  whitish layer, formed of serous  vessels like the
first.
   There  are then, according to this, four parts in the
mucous body, and by adding the two  white layers to the
two portions admitted by Bichat, and which  might then
be  regarded  as real  insulated  layers, avc.  should have the 
DERMOID SYSTEM.               259
 true  structure of this body.   But among these  layers,
 the first,  formed by the sanguineous bunches, docs not
 really belong to the mucous body; it is nothing else than
 the termination of the vessels ramified in  the  papillae,
 and forms a part of what was formerly called the papil-
 lary  body; so that the number  of  layers which consti-
 tute the mucous body may be  reduced to three; this  is
 what M. Dutrochet has  done in the analysis he has given
 of the structure of the skin of quadrupeds.   He has re-
 cognized  the existence of  these layers,  such as M. Gaul-
 tier has described them ; only he has designated them  in
 the following manner ; the skin is composed according  to
 him,  1st,  of the dermis;  2d, of  the papillae;  3d, of the
 epidermoid membrane of  the papillae, Avhich  is the deep-
 seated whitish layer  of M. Gaultier;  4th, of a coloured
 layer; 5th, of a horny layer, Avhich answers to the super-
ficial whitish layer; 6th, of epidermis.
  The existence of a mucous body  between the dermis
 and epidermis,  composed of at least three layers super-
 added to  each  other, seems  to be demonstrated by the
 results which we have just stated ; yet all anatomists do
 not admit this existence.   According  to M.  Chaussier,
 the skin has but two  distinct parts,  the dermis  and the
 epidermis ;  the one containing all the  organic elements
 of this membrane, without the possibility of establishing
 the boundary between these elements, the other being the
 inorganic  or non-vital  portion  of it.   Haller, Camper,
 Blumenbach, &c. were inclined to  reject the mucous body
 in the skin of the white, and to  admit its existence only
 in that of  the negro.
  When the epidermis is  removed by  maceration from a
 portion of very black skin, from  that  of the scrotum of
 the negro, for example, the colouring matter remains in
 part upon the  dermis and in part upon the epidermis, 
260
ADDITIONS TO THE
more however upon the latter; but if the maceration be
continued, this matter is detached from  both, and  depo-
sited at the bottom of the vessel, Avhere it  can be collected ;
it has  great analogy with  the colouring  matter  of the
blood.  This matter does not appear to be formed  in the
coloured layer or gemmules in which it has its  seat;
the papillae are the  secretory organs of it, as  well as of
this layer itself.  When Ave produce by a blister the sepa-
ration of the epidermis and  of the three subjacent  layers
from  the mucous body, the  denuded  dermis,  at first red
and deprived of its colouring matter, aftenvards takes  it
again ; Avhen the blister  is dry this matter is reproduced
in the form of little black points Avhich gradually enlarge
and are finally confounded  together,  so  that the cicatrix
is black though the mucous body may have been removed.
M. Gaultier attributes principally to the hairs  the func-
tion  of secreting this matter, because it  is more abundant
where the hairs exist, and  on account of the form it as-
sumes in  the  case of  Avhich we have just spoken ; but
since  it is  met  with  in all parts of the  skin, it  is not
probable that  its source is different according to the place
it occupies.
   Besides,  the colouring matter  of the skin  is  by  no
means stagnant in the  mucous  body ; the modifications,
which  it experiences  under many  circumstances,  show
that  it is incessantly  brought there and again taken  up by
vessels, and consequently subjected to,  a real circulation.
Thus  various  authors cite  examples of changes, almost
instantaneous, taking place  in the colour of the skin, of
women becoming black during pregnancy, of  men who
have experienced the  same  change  from age or extreme
grief; thus negroes whiten  more or  less in  diseases, old
age, &c.  At  birth,  the negro is not coloured ; his skin,
similar to that of the Avhite, is  red like it,  and only 
DERMOID SYSTEM.
261
slightly yellowish.   It is not till after birth that a broAvn
circle surrounds the nails, eyes, nipples and genital parts ;
on the third day  these parts alone are black; the rest of
the body is yet only taAvny.   On the seArenth, the colour
is  general  though pale,  and  continues so during  child-
hood ; its intensity increases gradually in  the adult age,
without acquiring however the same shade everywhere ;
the parts that are  first coloured remain generally the dark-
est.  These successive  changes which are also observed
in the other races, are so  many evident proofs of the
motion of Avhich  the colouring matter is the seat.
   This matter has the greatest relation Avith that which
colours the hairs, the iris and the choroid coat;  thus  all
these parts undergo the same change as the skin Avhen it
is  deprived of  its colour, as is seen in albinos,  from a de-
fect of organization.
   The two other parts of  the mucous  body, viz.  the
horny layer and the epidermoid membrane of the papillae,
or the two Avhitish layers are not so well known  as the
coloured layer.  These layers besides being  apparent in
the negro, are seen  under  many  circumstances.  Thus
the bulbs of the hairs exhibit on the interior, species of
flakes  Avhich appear  to  be formed by the epidermis of
the papillae; when  the nail is separated from the papillae
which are  beloAv it, as  may happen from a  blow, these
papillae are covered Avith  a  concrete matter which  is
nothing else than  this  epidermoid layer.  The horny
layer,  by  its extraordinary  development,  produces  all
those horny productions which appear on the skin, either
in a natural state, as the horns of animals, the scales of
fishes and  serpents, the nails, &c. or in the  state of  dis-
ease, as the horny substances which sometimes arise  on
the skin of man  ; these  productions, all situated below
the epidermis,  evidently belong to the layer of which we
are speaking. 
262
ADDITIONS TO THE
   The sanguineous bunches,  as we have  seen, are con-
founded Avith the papillae ;  these make a part of the der-
mis  or chorion, Avhose external  face  they occupy, and
ought not  to  be distinguished from them, as has been
done, under the name  of papillary body^  Their arrange-
ment is remarkable ; the rugae Avhich they represent form
regular lines separated by very evident furrows, and, in
addition, another  furrow,  not so  deep as the first, but
having the  same  direction, divides  each  of these lines
near its summit into  two  secondary elevations,  so that
Avhen the skin  is cut  across perpendicularly to the direc-
tion  of these lines, the species of curved thread Avhich is
seen along  the divided edge  exhibits undulations  alter-
nately large and small; it folloAVS  from this arrangement
that each prominent line, simple at its base, seems  to  be
composed at its summit of a double row of papillae.
   The structure of these rugae  of the dermis is almost
wholly Avascular ; their analogy Avith the  papillae of the
tongue and  the phenomena that  are  observed  in  them
seem  to prove that the nerves are very numerous, and
that there is a peculiar venous arrangement, analogous  to
that of the erectile textures.  It is to this very evident
arrangement, as well as to the nervous structure, that the
papillae of the  tongue  owe the kind of erection of which
the)' appear to be  susceptible.  This  erection is evident
in the tongue.  The  papillae of this organ are soft, flat-
tened and   indistinct  at the  period  of  digestion, but
straighten up and  become more apparent during masti-
cation.   Something similar is seen  on the  skin of the
fingers ; the pulp of this part often acquires  in the  exer-
cise  of touch, a  peculiar firmness,  tension,  and at the
same time redness.
   It is in the  papillae, that most  of the  phenomena  of
s'italilw of which the skin  is the seat, take  place: it is 
                  DERMOID SYSTEM.               263

there that  the feeling  and touch  are  exercised;  it  is
there that all the parts  Avhich are more superficially situ-
ated are secreted, there the colouring matter is formed,
there the  hairs,  nails,  feathers, horns, scales, &c.  are
produced.  We cannot be astonished  then at the  quan-
tity of vessels  Avhich terminate there ; the Avhole  capil-
lary system of the skin is brought there  by the  nature
of the functions which  they perform.  This idea how-
ever should  not  be  exaggerated,  and  it  must not  be
thought  that  there are  vessels nowdiere  else, that  the
texture of  the  chorion  more deeply situated is destitute
of  them, and that all  go to its surface;  the dermis is
often injected in its whole thickness, both from inflam-
mation and fine injections ; only the surface seems to  be
more so.  By taking from a  portion  of  injected  skin,
rendered transparent  by immersion  in the oil of turpen-
tine, a thin strip,  cut in  the direction of the thickness
of the membrane, and by examining it against the light,
we do not  see in it more vessels on the external than the
internal  side.  Finally, if all the vessels  of the dermis
were contained in  a superficial  layer, we might,  by
scraping the  external  surface  of a portion  of injected
skin, destroy these vessels, and remove from the dermis
almost all its red colour; now,  this cannot  be done.

                Cutaneous Absorption.

   Page 298.—" Many modern  philosophers have pro-
duced numerous negative  facts against cutaneous absorp-
tion."

   This absorption is much less marked than that of the
mucous membranes ;  it is not in fact evident unless there
is friction  or excitement of the skin, by Avhich the epi- 
264
ADDITIONS TO THE
dermis is opened, raised up, or in part detached, and it
does  not appear to  take  place  from  mere  contact;  at
least  there  are more facts  against than  in favour of this
last  mode  of  absorption.  Bichat  explains  these  facts
Avhich are apparently in contradiction to those in which
the absorption  is evident,  by the  varieties of sensibility
which the skin exhibits ;  but he  has not made the dis-
tinction which  we have just established, and it is easy to
observe that it  is when the skin is only in mere contact
Avith the substance subjected  to its absorption, that this
is  the most doubtful.  Thus  water  applied on the  sur-
face of the  integuments most usually is not absorbed, as
Bichat had already  remarked, and Symson, Avho pretends
that  he has seen a foot-bath sensibly diminished  after it
had been used by a patient, has been contradicted  by all
those Avho have since repeated  the experiment.  That of
Mascagni, in which the inguinal glands are swelled under
the same circumstances, is but an  insulated fact, and one
Avhich besides may  not be  owing to the absorption of the
liquid.  It is indeed said, that by holding one  hand im-
mersed  in a vessel  of mercury, and by having in the
other a piece  of any metal that  is susceptible of being
attacked  by it,  as gold or silver, the  latter blackens, pre-
cisely as  if  it were in direct contact with the mercury ;
whence it has  been inferred, that the  mercury Avas ab-
sorbed on one side and then carried into the blood, which
afterwards transmitted it to the opposite side ; but is the
fact certain, and have all  these circumstances of it  been
observed ?  Some  experiments, made Avith  the greatest
accuracy by Dr. Rousseau  of Philadelphia, prove on the
contrary, that the essential oil  of  turpentine, the absorp-
tion  of  Avhich  is so rapid by the  mucous surfaces, as  we
know, does  not produce  in the urine that  characteristic
odour, the unequivocal indication of its absorption, when 
DERMOID SYSTEM.
265
it  is merely applied upon the skin, taking care not to
allow it to  be introduced  by respiration.  Before  we
admit this absorption,  let us  wait till new experiments
luve demonstrated the reality  of  the  absorption by sim-
ple contact.
   As to the  irregularity which Bichat attributes also to
the other species  of absorption, founded upon  this, that
the insertion of virus is not always followed Avith success,
it  is possible in fact that the virus may not be absorbed in
this case;  but  we should be careful not to confound its
passage into the  blood with  its apparent effect,  especially
when  this effect is purely  local, the  first might  very
well take place, and the other not exist.
   The same  remark is applicable to  what most  authors
say respecting the  greater facility of absorption  during
sleep, hunger, ice.  and in general in  all the states  Avhich
dispose to weakness.   Contagious and  other  miasmata
are perhaps more  active under these  circumstances only
from the greater susceptibility of the organs.
   Some authors  have spoken of  a  gaseous  absorption
Avhich  is  constantly taking  place upon the integuments,
and  the result of Avhich they have endeavoured to  esti-
 mate ; according to others, the skin is the seat of an exha-
 lation of the same nature.  It is  evident that if these two
 functions  exist  there, their effect  must  be  confounded,
 and  that  it  is impossible,  by collecting  the  gases, the
 atmospheric air, for example, Avhich may have remained
 on the surface of the skin,  to distinguish if the changes
 of proportion  that are observed in them arc  owing to a
 diminution of some of their principles or to  an increase
 of the  contrary  ones, and consequently to  determine
 Avhat belongs  to exhalation and Avhat to absorption.   It is
 then incorrect to  say, as Fourcroy has  done, that the
 skin gives out azote; the nature of  this exhalation, if it
                    34 
266              ADDITIONS TO THE
takes place, Is very difficult to  be determined.  Besides,
the proof  which Fourcroy has  given  of its  existence,
drawn  from the bubbles that are disengaged from the
surface of the body when it is immersed in a  bath, does
not appear to me to be substantial.  These bubbles are
nothing but the air which adheres to the integuments and
which has become rarefied by the heat of the bath ; when
all this  air has once escaped, the disengagement ceases ;
these bubbles  are not seen to form in the cold bath, the
air not having there, from the want of dilatation, the same
tendency to quit the surface of the skin.

                  Sebaceous Glands.

  Page 307.—" There  is I think as much probability in
the supposition of the exhalation, as of that of the secre-
tion of the cutaneous oil."

  The existence of the sebaceous glands or  follicles of
the skin is proved by the following considerations, which
have been already in part stated  in the  article upon the
mucous glands.
  1st.  These glands are apparent in many places, as on
the  nose, the forehead, the  hairy scalp, around  the lips,
in the hollow of the axilla, in the groin, in the neighbour-
hood of the nipples and  arms, and in general wherever the
cutaneous  oil is secreted in great quantity.   M.  Gaultier
asserts that the  bulbs  of the hairs  are surrounded, at
their orifice,  by nine sebaceous follicles  destined  to
furnish the oily matter  which lubricates them.
  2d. These glands are very variable in their size, and
there are subjects in whom they  do not seem  to exist in
certain  parts,  in Avhich  they are found  very  large in
ethers ; so that by thus  collecting together all the insulat- 
fr
                  DERMOID SYSTEM.              267

ed observations, there is perhaps no  part of the skin  in
which they may not have been met with.
  3d. They often appear suddenly where they Avere not
before distinct, and  even acquire so great a size  as to
constitute a real disease.  It is not  probable that, in this
case, these glands  are formed  all at once ; their arrange-
ment is too similar to what  they  exhibit in the places
where they are naturally observed.
  4th. The same  substance everywhere  covers the sur-
face of  the skin; the organs  which furnish it must then
be generally distributed.  Now the sebaceous follicles
are evidently these  organs, in the parts where they dis-
tinctly  exist.
  It may  then be  accurately deduced from  all this, that
the sebaceous glands exist everywhere,  and  that  their
tenuity alone often prevents them from  being perceived;
that consequently  the oily fluid of the skin is, as is gen-
erally thought, the product of a secretion.
  The  structure of these glands is analogous to  that of
the mucous glands, which we have described ; the  skin
folded upon itself  appears in general  to constitute them.
The membrane which forms them is  continued with the
dermis ; the epidermis  is very apparent  in the  tumours
which result from their dilatation ;  these  tumours, when
cut open  and  emptied of the matter they contain, are
evidently  covered on the interior by an  epidermis, which
is detached from  them  by maceration with  that  of the
neighbouring skin.  The horny layer itself is indicated
in these follicles by the productions  of that kind which
are sometimes  developed in  them ;  in fact,  hairs  have
been seen  to derive their  origin from  them, and horns
to arise in them and push out through their orifices ; the
coloured layer is also evident  in  them  under some cir-
cumstances. 
268
ADDITIONS TO THE
      MORBID ANATOMY  OF THE  DERMOID SYSTEM.


        I.  Alterations in the External Forms.

   The skin when distended experiences various  changes.
 (Vide Vol.  3d.   Properties of Texture of the Dermoid
 System.)   When it is so for a  long  time, the fibres of
 the dermis are not  only separated, but they are broken
 in various places ; hence the whilish striae of the skin of
 the abdomen of women  who  have been  once  or many
 times pregnant; these  striae,  often important  in  legal
 medicine, because they are  constant, are  real cicatrices.
 When the  distension has been many times repeated or
 carried very far, the skin haA'ing lost in part its tendency
 to contract,  becomes  larger than is necessary to cover
 the subjacent parts, and remains loose  and soft,  or forms
 folds, as is seen on  the  skin of the  abdomen ; it is the
 same  phenomenon as  that Avhich  produces  the  Avrinkles
 in old people who become emaciated, as  has been  said
 elsewhere.   Besides, the skin  varies in this respect in
 different  individuals ;  one  Avoman, after  the first preg-
 nancy, has  the abdominal parietes more loose than those
 of another, whose abdominal parietes remain smooth and
 uniform,  though she may have had many children.  Age
 has also much influence upon it.   The  same differences
 exist in  diseases, when a tumour, for  example,  has  vio-
 lently separated the  skin of the  neighbouring  textures ;
hence the  modifications to be  observed with regard to
 the quantity of the  skin  to be  left, when  these  tumours
are removed,  according  to the age, sex, idiosyncrasy,
size, duration of the tumour, &c. 
DERMOID SYSTEM.
269
   The surface of the skin  is deformed  by many produc-
tions of a very different nature.  Some are  the evident
product of inflammation ; they will be noticed hereafter.
The others constitute  peculiar degenerations,  and will
also be  presently examined.   But there are  some which
seem to depend only on a preternatural increase of some
one of the layers of which the skin is composed.  Thus
the horny layer is raised up upon the integuments in the
form of  hard excrescences, in eA'ery respect similar  to
horns ; the  vascular net-work of the  papillae raises  the
delicate epidermis, and produces exuberances  more  or
less red, such as the growths from syphilis ; the substance
of the dermis itself grows and is produced on the surface
and forms warts.
   The  horny productions, respecting  which  there  are
many observations  in  existence, do not depend simply
on the cause that we have just pointed out;  they may be
divided into three kinds.  1st. In consequence of wounds
and ulcers, there  is often formed upon  the  cicatrices
productions of this nature.  2d.  The sebaceous follicles
are also sometimes  the origin  of these horns,  of Avhich Sir
Astley Cooper and  Sir Everard Home have given exam-
ples ; they have then concentric layers  such  as  are  seen
in trees.  3d. Finally, there are horns which  arise irregu-
larly upon all  parts  of the skin, and  which cannot  be
referred  to  either  of the two preceding  species ; these
are those especially which  seem to have their seat in the
horny  layer of the skin,  and to be  nothing else  than
a more  copious secretion of this  layer, from the irrita-
tion of the subjacent papillae.   Corns on the feet are
from a very similar source ; they are formed by a small
hard round body,  arising from  the horny substance  of
the skin, and  covered by the  laminae of the epidermis ;
only this  species of horny matter is forced  by pressure 
270    '           ADDITIONS TO THE
into the  substance of the  dermis, and sometimes even
below it, instead of growung on its surface.
  The enlargement of the  sebaceous follicles of the skin
produces  a  peculiar kind  of tumours.  When  this  en-
largement is inconsiderable, the tumour, hardly percepti-
ble, is discoverable on the surface of the skin only by a
black point, from which can be pressed out the sebaceous
matter contained in it, and taking the  form of the  aper-
ture of the follicle, escapes under the form of a  small
worm, and  has  eA'en been  sometimes  taken,  on this
account, for the larva of an insect; this  black  point is
owing to  the particles which float in the  air and which
soil the  entrance of the  follicle.  When the matter is
accumulated in  greater  quantity, the  tumour  is  more
prominent,  and constitutes,  according as the orifice of
the follicle  is  open or not, those pimples, so  common
on the face, on the skin of the nose especially, or the sub-
cutaneous wens that are seen  in  the various parts of  the
body.  These  never  depend  on any  other cause ;  all
those  pretended meliceris, atheromas  and steatomas,
which are developed on the head, under the hairy scalp,
in  the sub-cutaneous cellular  texture of the extremities,
thorax and abdomen, and which differ  only in the  degree
of consistence of the  matter which they contain, as their
names imply, are at first situated in the substance of  the
skin, as  is  easily proved by examining  them  in their
commencement.  There  may  be   often observed  in  the
same subject the kind of gradation Avhich  these tumours
follow in their  progress, that  is Avhen  there are many of
them ; the smallest then  exhibit  an opening very appa-
rent on the surface of the skin, whilst the others remove
by  degrees from the integuments, to which they are still
however attached, in  the greatest number of cases, by a
hollow filament, which is  the neck of the follicle elon- 
DERMOID SYSTEM.
271'
 gated by distension.  There are no true wens but the
 fatty tumours.   Thus the  substance of those  called en-
 cysted perfectly resembles  the  sebaceous  matter of the
 follicles ;  this  kind of tumours ha\Te,  like  the  latter,
 an  internal  epidermis.    These  last  characters  Avould
 almost alone be  sufficient to establish  the identity  of
 these tumours with the follicles, if their connexion with
 the skin in  the  beginning  could not  be demonstrated.
 The opening of the follicles, instead of being obliterated,
 is sometimes so enlarged, in those small tumours of the
 skin before  noticed, that  the  bottom of them is  almost
 completely  exposed ; their internal surface,  in contact
 with the air, then  becomes dry, the  tumour ceases  to
 grow, and there remains simply in the place it occupied,
 a kind  of cul-de-sac, continuous with  the  skin,  which
 appears to be there folded up.  This arrangement renders
 the structure of the follicles very evident.
   The Avhole  cutaneous  system is  the seat of a kind of
 atrophy, in the marasmus, which succeeds sIoav diseases;
 in this case  the colouring matter disappears, the dermis
 dries and is  thinner, the papillae are diminished and the
 skin becomes rough from the prominence  of the  bulbs
 of the hairs  which are below it.  Opposed  to this state
 is the  superabundance of  life  so common in the integu-
«ments  of the  face, especially in drunkards,  and  which
 is shown by the  vascular  bunches in this part.   A long
 continued irritation may also thicken the  dermis, as  is
 often seen around old ulcers.

          II. Alterations in the Organization.

   Cutaneous phlegmasias form a  numerous class in  patho-
 logy ;  but their infinite shades are confounded in great
 measure  in  the  eyes of the anatomist.   The  alterations 
272
ADDITIONS TO THE
of texture Avhich they produce  in  the skin are always
nearly the same, however numerous may be the eruptions
Avith  Avhich  they cover it.  The common characters of
most of the exanthemata, both acute  and  chronic are  an
increase of blood  in the  capillary  net-work, and  conse-
quently a greater development of  this net-work, either
generally, or in points more or  less precisely insulated ;
a fluid differing from the blood raising up  the epidermis
or spread on  its surface and forming there various kinds
of scabs ;  the epidermis itself in various ways altered and
its regular production  often prevented.  These affections
do not essentially differ except  in  the degree of excite-
ment  which produces them, the different structure of the
skin in the  parts Avhich they occupy, and the peculiar
habit  of the  persons  who  are  affected  Avith them  ;  all
these  circumstances produce modifications in  their  pro-
ducts.   Perhaps  however this  subject deserves  new re-
searches ;  since the seat of these diseases in the cutaneous
texture does not appear  to be always the same ; since
tinea, for example, seems  to arise  more  especially from
the sebaceous follicles, and some eruptions appear to  be
confined to the most superficial layers of the skin, whilst
in others the  whole substance of this membrane is altered.
In general, all those who have written upon the diseases
of the  skin are more engaged in describing minutely the
forms  they affect  upon this membrane,  than  in investi-
gating the changes they produce in  its organization.
   Besides, the usual  effects of inflammation have been
observed in the skin.   It  suppurates, not  only Avhen  its
epidermis is  removed, as from  a blister, but even Avhen
its texture is sound, in the same way as  the cellular  tex-
ture ;  the pus is  usually in  small cavities which raise up
the epidermis, as is seen in the pustules of the small  pox.
Ulceration is frequent in this membrane, less so  however 
DERMOID SYSTEM.
273
than in the  mucous system ; it  is sometimes connected
with suppuration, as  is commonly observed  in the small
pox; at other times it is the effect of a peculiar cause,
such as syphilis.  It is necessary, moreover,  to  distin-
guish  those cases in  which  ulceration proceeds  from
without inAvards,  from those in which the  skin  is dis-
tended, at  first  only becomes  thinner  and  is  finally in-
flamed and  destroyed,  from within  outwards, as  takes
place Nti abscesses, aneurisms, &c.
  Simple  wounds of  the  skin heal quickly, and  without
the  formation  of fleshy granulations.  A plastic layer,
analogous  to  that which is formed  between  the  other
divided textures, and which  M.  Brachet has found to be
composed of gelatine and albumen, reunites at first weakly
the edges of the wound, which can  in the beginning be
separated  afresh,  without giving hardly  any pain,  or
occasioning the flow of blood, Avith  Avhich  this layer is
not yet penetrated.  Vessels are afterwards produced in
this substance,  which at the same  time  acquires more
consistence, and the cicatrix is complete.   This cicatrix is
soon confounded with the texture of the skin, from which
it finally cannot be distinguished.
   The phenomena are also very simple Avhen the skin is
destroyed only  in its superficial layers, and the dermis is
merely denuded; the epidermis is then  reproduced with
great rapidity over the whole extent of the  wound ;  this
is Avhat is  seen in blisters, burns of the second degree,
slight excoriations, &c.  If however the i rritation is great,
as in a burn,  suppuration comes on, and the cure is  not
so speedy ; but fleshy granulations are not formed unless
the suppuration is long continued, as in blisters.
   On  the  contrary, these granulations  exist necessarily
when  there is a complete loss of substance of the skin,
and the lips of  the wound remain separate; they always
              35 
274
ADDITIONS TO THE
precede in this case the formation of the cicatrix, which
then arises from  the various textures laid bare, particu-
larly from the cellular.
  The  skin  is but little subject  to organic transforma-
tions.   It acquires under some circumstances all the char-
acters of  the mucous membranes; this takes place, when
it  is long in  contact Avith  itself and deprived for a length
of time  of the air on its exterior;  a less  thickness of the
dermis,  a greater redness of its surface, Avhich continually
pours out a copious mucous fluid, and an extreme delicacy
of the  epidermis, covered  Avith very distinct villi,  are
observed in  this  case, an  example of which is cited  by
Hebreard in  Avhich this alteration was produced  in  the
hollow of the ham, in a paralytic patient, by the constant
flexion of the leg upon the thigh.   We have seen, in the
Cartilaginous System, that the skin sometimes experiences
the cartilaginous  transformation.
  The cancer of the skin assumes a peculiar form which
is only observed  in this membrane and in  the mucous
system;  it constitutes most often  ulcerations around
which  the neighbouring texture is little altered, so that
in  an anatomical view, there is no resemblance between
these ulcers  called carcinomatous and the other cancer-
ous affections.   There arises also upon the integuments,
in  some  cases, excrescences analogous to the cancerous
polypi of the mucous membranes.  In  the sub-cutaneous
cancerous tumours, the skin is  subsequently affected  in
two different ways ; sometimes  it contracts  a  very great
consistence, a remarkable kind of hardness  at the same
time that it adheres intimately  to  the parts which it
covers ;  sometimes it ulcerates from  Avithin outAvards, as
takes place in the ordinary termination of cancer. 
DERMOID  SYSTEM.
275
         III. Alterations in the Development.

   The  defects of conformation of the Dermoid System,
are, 1st, absence of the  skin to a certain  extent, where
it usually is found, Avhich is  scarcely ever  seen  unless
there is at the same time a want of the  subjacent parts,
as when the  cavities of the mucous  membranes exhibit
preternatural openings ; 2d, various elongations which the
texture  of the  skin forms, and  with which the surface
of this membrane  is  covered ; 3d,  the spots from  birth
or nsevi materni ;  these are sometimes merely an  altera-
tion of the  colouring matter, sometimes an affection of
the  A'ascular net-work, and  most  often become in  the
latter case after birth, tumours that are  called varicose,
and which have much analogy  Avith the erectile textures.
The spots are often covered with hairs.
  NeAv  integuments are preternaturally  produced  when-
ever the parts naturally covered by the skin are deprived
of this common covering,  as  after  wounds, ulcers,  ab-
scesses, gangrene, &c. ; the new texture  which is formed
under these  circumstances constitutes the  cicatrix.    I
would observe, upon this subject, that this word serves to
designate all the  modes of union  which take place  be-
tween divided  parts; now there is  a number of  these
modes,  and  consequently  several  species  of  cicatrices.
1st.  There are  those which succeed  the internal ruptures
which various organs experience, the skin  which  covers
them remaining  sound ; those of the different systems
have  been examined under each one of them in particu-
lar ; we have seen that  they partake in general more or
less of the textures in which they are situated,  though an
analogous cause, an exudation of a substance  capable of 
276'
ADDITIONS TO THE
 concretion, most often presides over their formation in
 the beginning.  There are no  fleshy granulations Avhen
 these cicatrices are completed.   2d.  The union of \A-ounds
 by the first intention  furnishes a  second kind of cica-
 trices, which has great resemblance  to the preceding, and
 which only differ from them in  this, that the divided tex-
 tures communicate at first on the exterior, a circumstance
 Avhich their mutual contact soon renders nothing, so  that
 this case is then the same as the first.  The skin and the
 cellular texture perform- the greatest part in this union,
 which is  effected, like the  preceding, Avithout the pro-
 duction of fleshy granulations.   3d.  Finally, cicatrization
 properly so called is  the  mode of cure of wounds, and,
 in general, of all solutions of continuity that are apparent
 on the exterior, whose neighbouring edges remain sepa-
 rate, whether  because they have suffered too  great a loss
 of substance, or because the effects of contractility of tex-
 ture have  not been prevented, or because the  structure of
 these edges renders their approximation impossible, as in
 wounds of the bones.  There is in this case, the only one
 Avhich we should  notice  here,  suppuration, formation of
 fleshy  granulations,  and  consequently  of a  membrane
 analogous  to the skin.  This  membrane  is every where
 the same,  whatever may be the denuded texture, as is
 proved  by the  homogeneous  cicatrices  which  succeed
 amputations, wounds of the cranium and the thorax, in
 which parts of a very different nature are concerned ; the
 cartilages  are  the  only organs  Avhich do  not contribute
 to its  formation.
  Two periods may be distinguished in  the cicatrization
of a Avound ; 1st, the wound is covered with fleshy granu-
lations ; 2d, an epidermis is formed upon these granula-
tions, to give origin to the cicatrix.   It Avould be easy to
show that there .is  a greater number of  these; but these 
DERMOID  SYSTEM.
277
are sufficient to give  an idea of the mechanism  of  the
production of the cicatrices.  These periods are described
in Bichat, Vol.  1st.   We shall  now pass  them rapidly
in review.
   First Period.   The small bodies so improperly called
fleshy bunches, and Avhich havre also been known  by the
name of caruncles, granulations and  cellular and vas-
cular  bunches, arise in  proportion  as  suppuration is
established, but with a different rapidity in the different
textures ; in an amputation, for example, they are de-
veloped in the first place upon the  cellular texture which
occupies  the interstices of the other parts, in the  second
place on the surface of the divided muscles, soon after on
the fibrous organs, and still later in the bones, most often
in these last not until  a delicate  lamina is detached from
them ;  in general  they are produced so much the quicker
as the textures are more cellular and vascular.  The size
of these  bunches  varies ;  their arrangement  is so much
the  more regular  in  proportion as they are smaller, and
the cicatrization of them is also quicker.  The membrane
Avhich they form by their union  has  below it a compact
cellular texture, appearing as if penetrated  with concrete
albuminous  fluids.  This membrane  contains  blood  ves-
sels, for the bunches bleed from  the least touch, and  red-
den  or become pale from various causes.  The absorbents
are  not demonstrated in it, except  by  the  absorption
which  these bunches  perform, and by the ulceration to
which these are so disposed, that often by a deviation in
regimen, they totally disappear  in less than  two hours
from the surface of a wound ;  their extreme sensibility
leads to the belief that there are  nerves in it, though they
have never  been   seen.  The membrane  of  the fleshy
bunches  is endowed  with a very evident contractility,
which  explains  the real contraction  and  diminution of 
278
ADDITIONS TO THE
wounds, which is so much the more evident as  the skin
is at the same time more moveable and  extensible.  The
cellular nature of this  membrane has been demonstrated
elsewhere ;  many authors consider it, Avith  Fabrus, as a
mere extension of the cellular texture; but  the  opinion
of Hunter, which has been more fully explained by Home,
is more probable.  This opinion, which I have given in
the Additions to the  Cellular and Capillary Systems, con-
sists in  considering it,  not as a preexisting  cellular tex-
ture, but as a new production, not being able to be formed
except where there are cellular texture and blood vessels,
and exhibiting in its development phenomena analogous
to those of the natural  development of the organs.
  Second Period.  When the fleshy bunches have  re-
tracted as much  as the resistance of the integuments in
the neighbourhood of the wound will allow, they are cov-
ered with epidermis, which constitutes the second period
of cicatrization, the formation of the cicatrix.  The new
epidermis begins to be formed at the circumference of the
Avound, where it is evidently continued with  the neigh-
bouring  epidermis, and aftenvards advances by degrees
towards its centre ;  sometimes, as in large ulcers  of long
standing, it  is produced at the same time in small  parti-
cles in  the  middle,  and  the various points  afterwards
unite together ; the pus ceases to be secreted in propor-
tion as the epidermis is formed.  The cicatrix   is  com-
plete when  the  Avhole extent of  the Avound is  covered
with epidermis.   This  cicatrix, delicate at first, soft, red-
dish on account of the  want of thickness of the epidermis
which covers it, more  adherent  and less solid than  the
skin, finally  becomes completely analogous  to this  mem-
brane.  The cellular texture which is below it regains by
degrees all its extensibility,  unless the  cicatrix rest upon
a bone ; in this case it remains adherent. 
DERMOID SYSTEM.
279
  The new cutaneous texture when  perfectly developed,
exhibits  the  following  characters.   1st. This  texture is
more dense than that of the skin and has a greater resem-
blance to the fibrous textures ; fewer blood vessels enter
it, hence the  white  colour of the cicatrices and the rare-
ness  of  their  preternatural redness.   2d. The  dermis,
which is met with in it, has less evident areolae, and  less
distinct fibres and laminae than that of the skin ; this  der-
mis is in general destitute of papillae, as the smooth  and
shining  appearance  of  its  surface indicates.   3d.   The
epidermis is  very apparent in cicatrices, and is confound-
ed  with that of the surrounding skin.  4th. Camper has
denied the existence of the mucous body in it; but  this
body  is demonstrated  there, in negroes, by the  colour
of which their cicatrices are the seat.   This colour exists
in almost all  cases ;  only a sufficient length of time is re-
quired for it  to be developed, and the  tint it  assumes is
almost always paler than that of the integuments; how-
eArer in some  rare  cases, this tint has been seen  of  a
deeper colour.  The horns which arise  upon the cicatrices
indicate in them the presence of the horny layer.  5th.
The texture  of the  cicatrix is  more  disposed  to  ulcerate
than the skin  properly so called ; ulcers  which  affect at
the same time these two membranes  make much more
rapid  progress in the first than in the second* 
 
ADDITIONS
TO THE
EPIDERMOID  SYSTEM.
Means of union of the Epidermis with the Dermis.—
           Exhalant and Absorbent Pores.

~ Page 351.—" By separating the epidermis by macera-
tion, which is the most proper means, we see  on its in-
ternal surface many small elongations of greater or less
length, and which, when examined attentively, appear to
be nothing but  the  broken extremities of exhalants and
absorbents.  In  fact these  little elongations .  .  . have all
of them an oblique course, and terminate in  the pores
Avhich, we have  said, pass  through the epidermis to go to
its surface."

  The nature of the elongations which are intermediate
between the dermis  and  the epidermis, and which can
only be seen by separating these two parts from  each
                 36 
282
ADDITIONS TO THE
 other, is not  easily ascertained.  Kaaw Boerhaave  and
 W. Hunter  maintained, which is nearly the opinion of
 Bichat, that  they Avere the vessels of the  sweat or the
 cutaneous transpiration.   But  injections  do  not reach
 these elongations ;  inflammation, Avhich renders the whole
 skin  vascular, does  not  colour them  sensibly.  Cruik-
 shank considers these filaments as epidermoid substance
 which has dipped  down into the areolae of the dermis.
 But do these elongations really exist when the epidermis
 is adherent  to the  dermis ?  Nothing proves it.  They
 should rather be considered as species  of  mucous tracts
 which are formed by the separation  of  the substance
 intermediate to the dermis and the epidermis, rendered
 fluid and viscid by putrefaction or stewing to Avhich the
 skin is subjected for the purpose  of separating  the epi-
 dermis.
   The existence of the pores themselves, such at least as
 are usually represented is far from being accurately demon-
 strated.   Physiological considerations, and even the injec-
 tions of  Haase would lead to  the belief that the openings
 of the vessels go to the last layers of the skin, that is to
 say, to  the  epidermis; but microscopical  examination,
 Avhich  is  more Avorthy of confidence than  physiological
 conjectures, does not detect pores in the epidermis.   By
 examining against the light the epidermis of a portion of
 skin from which the  greater part  of  the hairs has been
 removed, there is seen very distinctly transparent places
 which  have  been regarded as openings.  Leuwenhoeck
 thought even that he  discovered pores in the epidermis,
 and  he  has  giA'en a drawing  of them in his Arcana
Naturae.   But  as this great  observer  used only simple
lenses, Avhich magnify but about  a hundred and sixty
times, he has perhaps mistaken for pores the foramina of
 the hairs.  Fontana, in his Avork upon the venom of  the 
                 EPIDERMOID SYSTEM.              283

 viper, speaks of a texture composed of serpentine vessels
 which he  has seen by  the aid of the microscope; but
 M. de Humboldt, who has examined the human epidermis
 with a microscope that magnifies 35,200  times, asserts
 that the serpentine cylinders are folds and not vessels ; in
 some observations made  upon  the epidermis  magnified
 312,400  times, he  was unable  to discover  pores in  it.
 I have closed the extremity of a tube Avith a piece of
 epidermis, the tube containing  a  column of mercury of
 more than tw7o feet, and not a particle of the metal passed
 through the epidermis.
  It must be concluded from these different observations
 that there is  on the  surface of the  skin  a non-vascular
 barrier between organization and the atmosphere, and that
 whether  for  entrance  or for exit, substances must pene-
 trate this  barrier by  a sort of imbibition, which would
 approximate this extreme  part  of  the organization, to the
 most simple bodies of either organic kingdom, which are
 destitute of vessels.  In fact, as Ave have  just said, there
 are neither vessels, pores nor  any opening discoverable
 by  the microscope, whether the oblique insertion of  the
 hairs conceals those  which give passage  to them,  or
 whether the epidermis furnishes a sheath for them which
 exists after their remoAral and fills the foramina with which
 it is pierced.   We  cannot  however deny absolutely, the
 existence  of  the pores  from  microscopical  examination
 alone ; for if  we make a puncture in the epidermis with a
 very fine needle, we cannot discover this opening by the
 microscope, as Cruikshank  has proved by  experiment;
 the  same  thing takes  place  in a very delicate lamina of
gum elastic or caoutchouc, in which a very narrow open-
ing  is made; on  the contrary, the opening continues
 when perfectly dry epidermis  is  employed;  paper  that
is used for filtrating presents the same difference  accord- 
284
ADDITIONS TO THE
ing as  it is  dry or moist.  This point, which has been
much discussed by authors, does not appear to me to be
yet sufficiently clear.

        Epidermis of the Mucous Membranes.

  Page 369.—"What is the place in  which  the epider-
mis  terminates that  lines the  origin of the mucous sur-
faces, or if it exists everywhere, Avhere does  it begin to
become no  longer apparent from  the  action of our dif-
ferent  reagents ? We  cannot,  I think,  determine with
precision ;  it diminishes in an  insensible manner, and is
lost  as it were by degrees."

  Bichat leaves  here two questions unsettled ;  the first is
to know  if the  deep-seated mucous surfaces have an
epidermis ;  and the  second is,  at what place this epider-
mis  ceases  or changes  its  nature.   The  soft  and  pulpy
state of the deep-seated  mucous membranes, the very
great resemblance which exists between the composition
of the mucus and that of the epidermis, and the presence
of villi where this is but little apparent, lead to the belief
that it is in fact  wanting  in deep-seated  parts.  On  the
other hand, those who admit its  existence there cite the
cases of inversion of the rectum, of the small intestines in
preternatural ani, of the uterus,  &c.; in  Avhich a distinct
epidermis covers the whole of these parts ;  they rely also
upon the membranous excretions, Avhich, according to
them, have no other source.   These  reasons are  by no
means decisive;  there  is no proof that the epidermis of
the  preternatural ani,  for example, exists originally, and
that it is not formed afterwards entirely by the contact of
the air.  As to the  membranes voided in  phlegmasias of
the  intestines, the bladder, &c. analogy should teach us 
EPIDERMOID SYSTEM.
285
to regard  them as false membranes of the same kind as
those which cover under the same circumstances the eye,
the mouth, the pharynx, &c.   However it  may be pos-
sible that a very delicate  epidermis,  the fineness of which
would render it still more  difficult to be perceived, may
be found upon the deep-seated mucous surfaces ;  this first
question can  hardly be resolved otherwise  than it  has
been done by Bichat, who is much  inclined  to  the nega-
tive.
   The  second leads to something more positive.   In
many parts  of the mucous system, there exists a very
evident line of demarcation between the  portion of this
system  placed near the exterior and that which is more
deeply situated.   This line is owing to the  epidermis of
the first, which ceases where the  second begins.  Boil
the mucous  coat of the stomach and that of  the oesopha-
gus, the epidermis, raised up upon the latter, Avill soon form
a bunch corresponding exactly with the cardiac orifice,
and beyond which this epidermis will cease to be appa-
rent.    This is Avhat has even  led to the assertion  that
there was at this place  an interruption in the mucous  sys-
tem, and that  the  mucous membrane of the  stomach was
not a continuation of  that of the oesophagus.   But the
epidermis alone  forms  this  limit;  the  rest  of  the mem-
brane is continued perfectly.  This is  so  true, that in
animals, the  line of demarcation does not always corres-
pond with  the  cardiac  orifice, and often  this line en-
croaches more or  less  upon the stomach, as is  shown in
the plates  of  Home, in AA'hich it  is  seen  to  approach
nearer and  nearer the pyloric  orifice, according to the
species of animal.  It is  the same case with  the mucous
membrane of the vagina in  relation to that of the uterus ;
its epidermis  terminates at  the neck of this viscus, the
interior of which  is not the less  lined by a peculiar  mu- 
286
ADDITIONS TO THE
 coas membrane, differing from the first only in having
 a less degree of thickness and fewer villi.   The same ar-
 rangement exists at the neck of the bladder, as is proved
 by the  experiment noticed above, made upon this viscus,
 and the urethra which is inserted into it.   This remark
 applies  in general to all the mucous ducts Avhich open on
 the exterior, and terminate  in a membranous reservoir.


                 Nature of the Nails.

   Page 375.—" We cannot consider these" (the  nails,)
 "as mere layers of epidermis applied to each other."

   Malpighi regarded the nails as the consequence of the
 drying  of the papillae of the dermis.   Ludwig said  that
 they arose  from  the dried  nervous substance.  The ex-
 amination of the horny parts of animals shows that  they
 are formed by a horny substance, of the  same nature as
 that Avhich  constitutes  the  hoofs, horns,  scales,  &c. of
 various  animals.  The epidermis only covers these parts,
 which all belong to the  horny layer which is subjacent
 to it; Avhen it  is wanting on their surface, it  is because
 friction  has destroyed  it, or that it is confounded  Avith
 their  superficial  laminae, as is  seen  particularly   Avith
 regard to the nails.
  Considered in animals, these  are of  two species.    1st.
 They  are  such as  resemble  those of man,  these are the
 small nails  (onguicules.)  2d. Others  differ from  them
in their arrangement  have received  the  name of  nails
 (ongules); they include  the hoofs of various quadrupeds.
We might add to them  the horns, the  origin of which
 is precisely similar to that of the nails and the hoofs. It
 is necessary however to distinguish among these the horns 
EPIDERMOID SYSTEM.                287
of deer, and  the horns properly  so  called, or  those  of
ruminating animals.  The first  are entirely osseous, and
raise up the skin, instead of being seated on the surface
of this  membrane ;  the second alone belong to this sur-
face ; only they usually surmount  osseous elongations, to
Avhich they serve, as  it were, for  sheaths.   The nails of
man are  not coloured ;  those of animals and their horns
are so on the contrary quite often ; their colouring matter
appears to reside in general,  in the  horny  substance
itself.
  The nails and  the  horns are formed  by the  same me-
chanism.   When a horn is torn  out of an animal, the
papillae  in a high degree vascular, which  have been laid
bare, pour out  a fluid matter  Avhich can be seen  at first
to rope  between the  fingers,  if Ave may be alloAved  the
expression, and which afterwards thickens and  hardens
by  degrees ;  below  this first  layer, there is formed a
second which raises it, and then a third, and thus  in suc-
cession, so that a new  horn results from this  successive
union of layers ; this horn continues  to  grow from  its
base in  the same manner, the new layers  constantly rais-
in^  the old  ones.  Now the same  thing is observed in
the hoofs,  as also in the reproduction of the nails of man.
The form alone  differs, because the  parts  secreting  the
fluid  are variously formed.  When  the nail is torn out,
the papillae, after having bled  copiously, and  appearing
bare  though having  still above  them the deep-seated
whitish layer,  are covered with a soft,  white lamina, the
consistence of which  gradually  increases ;   then new
laminae are produced below, so much shorter as they are
more distant from the root, and give to the new nail the
thickness which  it is to  have ; the  ulterior growth  de-
pends on  this, that  the  horny substance is  continually
poured  out at the extremity of each of the laminae, which 
288
ADDITIONS TO THE
occasions the whole  of the  nail to  be pushed fonvard.
This  mode of development  may  be compared to that
which takes place in the  silk worm, the fluid of which
is constantly reproduced in proportion as it acquires con-
sistence, and constantly pushes before it  the fluid which
has preceded it.   Thus the nail would grow indefinitely
if it were not habitually cut, or worn off by friction.
   The longitudinal striae which the nails exhibit on their
surface are no indication of a fibrous structure ;  these
striae  appear to depend on the arrangement of the sub-
jacent papillae.
    MORBID ANATOMY OF THE EPIDERMOID SYSTEM.

  The parts comprised under  this system having  no or-
ganization, properly speaking, are subject to but a  small
number of alterations, Avhich  even  are  not inherent  in
them,  and depend only on the  changes that  are  expe-
rienced by the vitality of the skin, their common support.
It is Avith these parts as with the different fluids that are
poured out upon the mucous, serous, synovial surfaces,
&c. and the alterations of which depend entirely on those
of the organs Avhich furnish them.
  The epidermis thickens, becomes  thin, is raised  up  on
the surface of the dermis and destroyed by various causes,
the most of which have  been  already examined.   It as-
sumes  the form  of vesicles, blisters,  furfuraceous  scales
and  large plates, Avhen it is raised up or almost entirely
detached.   Its  reproduction,  usually easy,  sometimes
becomes impossible from the great irritation of which the 
EPIDERMOID SYSTEM.
289
skin is the seat, as in a burn or  chronic  pemphigus, and
then the  patients  suffer much,  the mucous  body being
bare. At other times, the skin, red and swelled, furnishes,
instead of the fluid which  produces it, a scabby, crusty
matter, joined to a serous fluid which oozes out copiously,
as is seen in some  species of herpes.
   The excrescences of the  nails are especially frequent
in the dry herpes, in which the  skin assumes the appear-
ance that has been  compared to the lichens of trees, in
Avhich the epidermis is thickened and cracked in various
directions.  They come upon the toes, from a cause  an-
alogous  to that which produces corns upon  them.  In
some cases,  they  appear to be owing to the progress of
age.
   The nails become soft and brittle in individuals  affect-
ed with scrophula  and  herpes.  They exhibit also besides,
in some  cases, a peculiar alteration which authors do  not
appear to me to have described.  It consists in  a  sort of
chronic  inflammation  of the skin  which surrounds  the
root of the nail;  a  brown  circle, painful when pressed,
is formed at  this  place ; the nail  becomes at the same
time thin and like  a membrane.  Buzzi has given some
examples of this affection, which I  have many  times ob-
served in children,  and sometimes in adults.
   The  very  improper expression of the nail  growing
 into the flesh serves  to designate a state  in Avhich the
 skin surrounding the  nail  upon  the edges or near its
 extremity goes beyond it and advances more or  less upon
 the free face.  There  results from  it pains more or less
 acute by the pressure Avhich the cutting edge of the nail
 makes upon it.   This inconvenience hardly ever happens
 except to the great toe, in  which the tightness  of the
 shoes often  produces  it.   The extraction  of the nail  is
 the most efficacious remedy for it.
              .37 
 
ADDITIONS
TO THE
PILOUS SYSTEM.
               Structure of the Hairs.

  Page 401.—"White hairs may experience vital phe-
nomena, of which, I believe,  there  are  a few examples.
But  all this  is  subordinate to  the  future experiments
Avhich will elucidate the pilous  structure  more  than  it
now is."

  This  structure exhibits some  new peculiarities Avhich
we shall  state.
  The bulb of the hairs, or the kind  of canal from which
thdy deriA'e their origin, is  in fact a  small sac  lodged  in
the  substance of the skin or in the sub-cutaneous cellular
texture, and receiving  the extremity of the hair which
is implanted in it.  This bulb is not very evident in man, 
292
ADDITIONS TO THE
but has  been described by Chirac and Gaultier, from its
arrangement in the hairs of the Avhiskers of some animals,
its size in them rendering its structure more evident.  It
appears to contain like  the sebaceous follicles, the  same
parts  as the  skin, and to be continued  in the same way
with this membrane.  A layer  analogous  to the dermis
is  the  base  of it, and is evidently continued  with the
dermis of the skin.  Within this layer there is  an  elon-
gation  of the mucous body, the  continuity of Avhich with
this  body is  seen  very well in animals  whose skin  is
coloured ; this part is soft and more easily  perceived than
the skin ; it is composed, as in the skin, of many layers.
The epidermoid layer is the inner one ;  it  is less distinct
thaii the others, but it  is found  in feathers, Avhich  have
a great analogy with the hairs, and in the  quills of quad-
rupeds, which are only  hairs made  very strong.   A  coni-
cal papilla, similar  to the asperities of the dermis which
surmount the palm of the hands, the sole of the  feet, &c.
fills the bottom of this kind of follicle.
   The bulbs of the  hairs receive vessels and nerves.  The-
nerves constitute in great part  the  elongations Avhich  go
to their external  face, and which occupy particularly their
extremity opposite to the skin, they form for them a sort
of pedicle.   Many  anatomists  have traced  these nerves
in animals ; in man even  nervous filaments are seen to
penetrate the  bulbs of the eyelashes and  those of the
hairs situated at the opening of the nostrils.  The Aressels
are also  situated, according to some, in  the substance of
the elongations attached to the  bottom of  the bulbs; but
M. Gaultier has seen them entering at the other extremity,
coming from the  dermis of the skin, and enclosed between
the dermoid  layer of the bulb and  the mucous layer.
   The  neck  of these small sacs is  surrounded Avith seba-
ceous follicles, pouring out an oily matter, which covers 
PILOUS SYSTEM.
293
the surface of the hairs, and the use of which is to render
them less brittle.  M. Gaultier thinks that there are nine
of these follicles, which are very small.
   The body of the hair embraces by its root the papilla of
the bulb from which it arises ; it is joined to the papilla
jn this place, nearly in the same way as horns and feath-
ers are united  to the  elongations which serve for  their
support.  In the interior of the bulb, the hair is  covered
by a sheath  which  is furnished by  the epidermis, and
which  is evident in the quills of quadrupeds, and especi-
ally in feathers;  this sheath is discontinued  at the  place
where  the hair traverses the skin to  go out, or at least it
cannot  be traced beyond there,  perhaps because  it  is
broken off even with  the  integuments.
   The  structure of  the hair  itself is a point that is not
yet  well understood.   This  part seems to  be,  like  thq
feathers,  horns,  scales, &c. a production of the horny
layer of the  skin; but it  is  difficult to ascertain the in-
ternal  arrangement of the  substance  which composes it.
The bristles  of the  wild  boar are formed by twenty fila-
ments leaving  in their interstices one or two canals which
contain a peculiar marrow.  On the  contrary the  hairs of
the elk, hedge hog, &c. have no  filaments; they are con-
stituted by a horny tube, filled with a spongy and  coloured
substance.  Hence  there  are two different  opinions  in
relation to the structure of the hairs  in man.  Some pre-
tend that they are filaments in juxta-position ; according
to others, their arrangement is that of a  tube.   Both of
these opinions seem to be equally well founded ; 1st, on
the one hand,  by examining against the light a black hair,
the edges of it are Avhitish and transparent, Avhich  seems
to show that  the exterior of the hair is  of a different
nature from  that of the interior, but which  may be also
owing to this, that  the   edge being thinner, the colour 
294
ADDITIONS TO THE
must be  less evident in it;  2d, on the other  hand, the
hairs in man can be divided into many filaments, which
either depends upon their structure, or the division is
purely mechanical.  -On the whole, the minuteness of the
objects prevents us from deciding on this  subject.  Only
it is certain that there is a colouring matter in  the hair,
and  that  this  matter occupies the  interior  of it.  The
hair is dyed with such substances as the  preparations of
lead Avhich  only colour  it  by  the  chemical action they
exert upon this matter.  But it is not knowm whether it
undergoes a sort of circulation in the  hairs, or if when
once deposited, it  is wholly beyond  every motion of the
fluids.   This matter is secreted with the hair itself Avithin
its horny substance.
  From all  that precedes, it is evident  that the tAVO  ele-
ments of the hair, the bulb and the body or the  hair
properly so  called,  have nothing  in common in their
structure, and consequently in  their properties ; that  the
hair, properly  so  called, is almost  inorganic, like  the
epidermis and the nails, whilst its  bulb on the contrary
enjoys a  very considerable degree  of vitality.   Hence
why the hairs,  though  insensible  themselves, transmit
such painful impressions Avhen  they  are  pulled; Avhy
they are so  useful  in  animals Avith whiskers, as organs of
feeling, the  least jar Avhich agitates their extremity being
felt in an instant ; why, in diseases, the hairs  are influ-
enced by various organs,  the functions of their bulbs being
deranged  by their  connexion with  the  other  functions ;
aud why nevertheless they  remain most often foreign  to
all the  disorders Avhich take place in the   economy, and
do not feel them for a length of  time,  &c.  This  sort of
productions  should be considered as the result of a  real
excretion of which the  bulbs are  the  seat.   Thus  the
hairs grow only at their  base, like  the  nails, of Avhich it 
                    PILOUS SYSTEM.                295

is easy to be convinced by observing this  growth upon
hairs artificially dyed, or upon which an  indelible mark
has been made ; the  distance of this  mark from the sur-
face of the skin increases only as the  hairs lengthen ; and
it is only near  this surface  that the  colour of the hairs
Avhich have been dyed seems to disappear, in  proportion
as their substance  is  developed anew there.  The cele-
brated Mascagni has  again  brought  forward, in  a post-
humous work,  an  opinion which  has been many times
before thrown out upon the structure of the epidermoid,
horny and pilous parts ; he regards them as a texture of
lymphatic vessels, and he attributes  the same texture  to
the enamel of the  teeth and  to most of the  organic tex-
tures.  But this vascular structure, which  HedAvig has
represented Avith so much truth in the  epidermis of plants,
does not appear to exist in the epidermis, hairs and nails
of man and animals.
       MORBID  ANATOMY  OF THE PILOUS SYSTEM.

   Preternatural Avhiteness is the most common alteration
of the hairs.  Much  has  been said of the  hairs having
become suddenly Avhite, and o\rer the whole extent of the
cranium at the  same time  ; Bichat has even cited exam-
ples of this fact.  But haAre  these cases been  sufficiently
observed ?  They should  be doubted, I think, especially,
as no one of them  has been related Avith  the necessary
details, until new observations confirm or  destroy them.
If the  facts are correct, they would  tend to  prove that
there is circulation in the  hair.   Those that are  well 
296
ADDITIONS TO THE
known  only prove that  an appearance of  sudden  dis-
colouration  may.take place, Avhen the  hairs fall out  and
are replaced by others of a different colour.   This is what
is often seen in phthisical subjects who  have  intervals of
almost  perfect health ; it then happens that their hair,
which had become white during the  paroxysm, falls  out
and  is  replaced  by black, which it was before;  Dr.
Chaumeton exhibited  this phenomenon a short  time  be-
fore his death.  This  may be  repeated many times  suc-
cessively, and the hairs may be thus  alternately coloured
and colourless according to the general state of the in-
dividual.  In  ordinary cases,  the change of colour does
not take place in all the  hairs at once, but  successively
in each of them ;  it  begins at the root and  gains little
by little, in proportion as this is extended and the  end
worn by the action of  foreign  bodies ;  this is easily ex-
plained by the change that comes on in the secretion  that
is made in the bulbs.
  Alopecia (or the falling out of the hairs) is accompanied,
under some circumstances and not under others, by a  sort
of atrophy of their bulbs.  This lesion is sometimes the
consequence of a  long-continued irritation, as in  tinea ;
at other times, though  rarely at  the present day, it  is
owing to  syphilis; but an  infinity of other  causes  may
also produce it.   The state  of the bulbs in these different
cases has  not been examined.
  The plica is an affection also, the  nature of  which  is
but little known.  The best observers are not agreed  as
to Avhat takes place in  this disease ;  according  to some,
the hairs acquire sensibility, and  are penetrated  with
vessels ; others assert that they are only matted together.
It Avould be possible to reconcile these  two opinions by
admitting that the hairs become  merely vascular at their
!:.\se, by an extraordinary growth of the papilla  contained 
PILOUS SYSTEM.
297
in their bulbs, a growth which would raise this  papilla
above  the  level of the  external  face of the  skin,  and
whose primitive irritation  having caused the disease, or
that secondary one resulting from  want of cleanliness,
pulling the  roots of the hairs, &c. would  easily explain
it.   The plica Avould then  produce a phenomenon analo-
gous to what is observed  in feathers, in young birds;  if
the papillae of their feathers exceed the level of the integu-
ments, they bleed when they are cut.
   Preternatural hairs are met with, besides under the cir-
cumstances noticed (Vol. 3d,) on the surface of the  skin,
and in consequence of the inflammation of this membrane;
M. Boyer mentioned in his lectures the case of a woman
whose thigh was  covered with long, rough hairs, after
erysipelas.   Among the cysts which contain hair, should
be noted those situated  in the superior eyelid, near the
eyebrow ; their hairs resemble  completely those of the
eyebrow,  and appear  to  be only some of them which
have deviated from their usual direction.   The hairs con-
tained in  the cysts  of the ovarium are  delicate, silky,
light coloured, usually  free from all  adhesion  and some-
 times swelled at one of their extremities.  It is extreme-
 ly rare that hairs  arise in cysts  formed in other parts.
 Hairs are sometimes found in the meconium of new born
 infants ; their origin is but little knoAvn ;  it is supposed
 that they existed  originally on the  skin of the foetus.
38 
 
PRETERNATURAL TEXTURES.
  IT remains for us, in order to complete  the summary
notice of the  principal changes which  the  organic  tex-
ture undergoes in diseases, to speak of the  degenerations
common to all the systems previously studied,  and Avhich,
not belonging in their  nature to any single  one of them,
could not be examined in their particular history.   The
description of these degenerations will be at the same time
a sort of completion of the General Anatomy, the different
simple  textures of AA'hich have embraced, in  addition to
the natural organs of the economy, only the preternatural
productions Avhich are analogous to these organs.  In fact,
the degenerations, though always resulting from a species
of transformation or degeneration Avhich affects the natural
textures in consequence of  the  morbid phenomena of
Avhich these textures  are the  seat, are really,  when  once
formed, independent to a certain extent, of these textures,
have in the midst of them their peculiar life, seem  as it
were to be new organs superadded to  all the others, so
unlike are they to those which  have given them  birth,
and are entitled from their structure and peculiar proper-
ties to form a distinct class, or if it be preferred, a system,
under the name of morbid or preternatural textures. 
300         PRETERNATURAL TEXTURES.

  These textures, considered in this  point of view, pre-
sent a certain  number of common characters, which  at
the same time mark the difference between them and the
natural textures of the economy.   1st. Their structure is
in general homogeneous, and though they seem to contain
various organized  elements, as  vessels and cellular  tex-
ture, those fibres  and laminae which characterize most of
the organic textures  are  not seen in them.  2d. They
have not, like them, a uniform organization;  their most
important  properties,  such  as  colour  and consistence,
change in their different periods ; in general hard and
firm in the beginning, they soften and become fluid even
in part, at a  more  advanced period,  which is precisely
the reverse of  the other textures.  3d.  Far from being
able to perform uses in harmony with  the other functions,
as is sometimes done by the natural textures  Avhen  pre-
ternaturally developed Avhere they ought  not to exist,
their presence always produces  more  or less remarkable
derangements in  the action of the organs ; emaciation,
slow fever and  death are  often the consequences of them.
4th. They have not a permanent  existence  in the  econo-
my, but have uniformly  a tendency to be  destroyed at a
certain period ; sometimes, it is  true, this  period is  late,
and they remain for a long time in the same state, making
a part of the organization, like the natural textures, it is
especially at the  period  of  their destruction that they
affect  the  health.  5th. The diseases  which affect them
have a peculiar progress  and effect ;  thus   inflammation
uniformly produces in them  the greatest  derangements
and a rapid destruction, which are propagated to the  sur-
rounding parts.
  The different preternatural textures may be met Avith
in almost all  the  organs ;  but there are some which they
more  particularly affect;  often in the  same   subject, they 
PRETERNATURAL TEXTURES.
301
are found distributed at the same time upon a great num-
ber of points.   These textures  frequently increase the
size of the parts which  they occupy, and form  tumours
prominent on the exterior.  Their  apparent situation, in
relation to the organs, presents in general, two varieties ;
in one, they seem to be  interposed  between the textures
Avhich compose these organs; in  the other, these textures
disappear,  and are  replaced  by  the  preternatural  pro-
duction.
   How are these  textures produced in the animal econ-
omy ? Bayle and Laennec attribute their development
to a particular disposition of an  unknown nature, which
exists in'  certain individuals,  and  regard  the external
causes which  are commonly assigned, at most  as  only
occasional  circumstances, wdiich  favour the action of this
occult cause.   Broussais, on the contrary, assigns to these
causes the principle  part;  according to  him, these pro-
ductions  are uniformly a result of inflammation,  and take
place when,  in  this, the white  vessels and  the lymph
which they contain are  especially affected, the irritation
not being  sufficient  to bring the red part of the blood ;
the albumen variously combined with the textures, is the
basis  of  these productions.   J. F. Meckel calls the  prox-
imate cause of this  kind of alterations, and generally all
the alterations of  texture,  an abberration of the process
of growth ; he  explains all these lesions in the same way,
as J.  Hunter and Abernethy do, by the effusion  of a fluid
albuminous matter,  taking  various forms and requiring a
peculiar  and  imperfect  mode  of organization.  Others
consider them as  productions analogous to  the  cryptoga-
mous vegetables, and  which are  nourished  and  grow
either by imbibition, or  by a real  vascular circulation.
Disregarding these theories, which are  more or less well
founded, we  shall  treat only of the anatomical characters 
302           PRETERNATURAL TEXTURES.
of the  preternatural   textures;  whatever  may  be  the
origin of these textures, it is important to know them.
  But  they exhibit in  this  respect  many differences,
which are not hoAvever striking, but are confounded with
each other by  insensible shades ; besides,  the parts in
Avhich they are situated, though not absolutely  having an
influence upon their nature, make them  howrever vary a
little, so that the study of them becomes  very difficult;
thus authors are not agreed in  the classifications which
have been given  of them.  Some have made many tex-
tures of the same production examined  at different periods
of its  development; we have  already noticed this source
of error.  Another, not less real, is that oftentimes many
of these alterations are  united together, whether they form
different distinct parts of one texture, or whether they are
intimately intermixed  in  this texture.  This union  may
take place not  only  between  morbid textures properly
so called, but also  between  these and the preternatural
textures  to which there are  analogous ones in the econ-
omy ; the osseous and fibrous productions, for example,
are often joined to the first, as is seen especially in  the
ovarium, the thyroid gland, &c.  Hence it follows  that
all these textures are far from being equally well knoAvn ;
that daily observation  shows  productions  which  do not
resemble any of those hitherto  described ; and finally
that there are very common  alterations, as the polypi of
the mucous  membranes, fungi  of the  dura-mater,  &c.
that we  knoAv  not Avhere to  class, and Avhich  appear to
consist  sometimes  in  a simple hypertrophy, and some-
times  in a  real  degeneration.   The  only preternatural
textures which  haA*e  characters at all striking  are,  1st,
Tubercles;  2d, Scirrhus ; 3d, Cancer;  4th, Melanosis.
We shall noAV examine them in succession. 
PRETERNATURAL TEXTURES.         303
                   I. Of Tubercles.

  Tubercles, or  scrophulous tubercles, so  called from
their  form which  is commonly round and from their
most frequent cause, exist under many forms, which are
so many degrees of this degeneration, and which may be
all included in two  periods, the one of crudity  in which
they are in a solid state and the other of softening.   M.
Broussais  considers this last as a true mode of suppuration
peculiar to this texture, and resulting, like ordinary  sup-
puration, from the inflammation which is developed there.
  First Period.   Greyish granulations, semi-transparent,
quite  firm, from the size of a grain of millet to a grain of
hemp and irregularly distributed, usually constitute tuber-
cles in the beginning.  Bayle, who  observed them in the
jungs in this state, thought that it was an alteration dif-
ferent from  tubercles; M. Laennec has proved that  it is
not so.  These grains, as they become larger, assume
another aspect;  they often unite together, and form more
or less  considerable masses ;  they always become opake
and yelloAvish,  at  first in their centre, and  then on the
circumference, nearly in the same way as cartilages which
are ossified, and acquire at the same time the consistence
of hard cheese.  This state, Avhich is properly that of the
crude tubercle, is  not always distinctly preceded by the
first,  in which the tubercle is  called  miliary.; there
sometimes takes place in  the beginning a sort of infiltra-
tion or impregnation of tubercular matter, Avhich suddenly
invades a  certain extent of the affected organ which  be-
comes greyish, more dense and semi-transparent; yellow
and opake spots afterwards appear in this place, and  the
second state comes on. 
304          PRETERNATURAL TEXTURES.

  The tubercular texture adheres most often to the sound
texture which surrounds it, it sometimes  even  seems to
be continued with this texture, and at others, on the con-
trary,  it is separated from  it with the greatest  ease.   In
some cases,  a membrane  in the form of a cyst  surrounds
the  tubercle; this  is especially when the tubercle is
developed slowljr.  This membrane  is not always of  the
same nature; sometimes soft, and as  it  were, like  the
integuments of pork, sometimes more consistent, it some-
times becomes cartilaginous and even osseous ; it  appears
to be the result of an exudation.
   The vessels are separated  or obliterated by the tuber-
cular substance ;  they are not Adsible in  the masses which
it forms.
  Second Period. The tubercles soften and melt as it were
from the centre  to the circumference ; they are  converted
sometimes into an opake, thick, yellowish matter, which
very much  resembles  cream, sometimes into a clear and
transparent  fluid, in which  flakes similar to cheesy matter
are seen to swim. The eATacuation  of these products  has
taken place, as in abscesses, sometimes externally  and some-
times  internally; the centre of the  disease,  which is
usually lined by  a membrane of new formation,  analogous
to the  cyst of which Ave have spoken above, cicatrizes, or
continues* open, and brings on suppuration and  ulceration
of the texture,  which forms the parietes  of it, or finally
remains  always, but is clothed  with a dry, semi-cartila-
ginous membrane, as Avas first observed by M. Laennec,

                   II. Of Scirrhus.

   The scirrhus  texture is  firmer than  the preceding ; its
consistence varies from that of the cartilages to the soft-
ness of  the inter-vertebral  fibro-cartilages ;  it makes  a 
PRETERNATURAL TEXTURES.
305
 noise  under the  scalpel.  Its colour  is  Avhite,  slightly
 blueish ; cut in thin  slices, it appears semi-transparent.
 It forms  more  irregular  masses  than  the tubercular tex-
 ture ;  it softens in the same way, and  is then changed to
 a  transparent,  greyish or reddish matter when a little
 blood  colours it,  exhibiting the appearance of a  jelly or
 syrup.
   The pancreatoid, mammary, (analogous to the texture
 of the mamma,) and tubercular  sarcomas of Abernethy
 should be considered as varieties of scirrhous. In the last
 of these three, the name of Avhich is improper, since it is
 agreed to give  the name of tubercles a particular kind of
 texture, and not a variety of form, the scirrhous  mass is
 divided into distinct lobes.


                   III.  Of Cancer.

   In pathology, various alterations have been designated
 under  this name, among which scirrhous,  which we have
just  examined,  has often been comprehended.  We shall
 understand only by cancerous texture what some have
 called  soft cancer ; it is the cerebriform or encephaloid
 matter of M.  Laennec, the fungous inflammation of
 Burns, the fungous hematodes of Hey and Wardrop, the
 medullary sarcoma of Abernethy, &c.
   This texture  has less consistence than  the scirrhous,
 though it has more than the cerebral substance ; it is of a
 milky  white, variegated,  when it is cut, by red points
 formed by the  divided vessels ;  these are in fact very
 numerous in it ;  but their parietes are  very thin,  and
 hardly bear the effort necessary for injection.   The masses
 Avhich  this texture forms are  divided on their surface by
 lobes convoluted nearly like  those of the  brain ; a Arery
                  39 
306          PRETERNATURAL TEXTURES.

soft cellular texture fills the interstices of these lobes.
These  masses occupy  at first but a very limited extent,
and are afterwards propagated in all  directions ;  this is
what is seen, for example, in the eye, which is frequently
the seat of this alteration, and in which it occupies most
often in the beginning, a single point only of the retina,
from which it extends  to the whole of the eye.
  In the period of softening, Avhich  comes on soon  in
this texture, and  the progress of which  is very rapid, it
assumes the appearance of the softened  cerebral substance,
and forms a sort of rose-coloured  jelly, on account of the
blood which is mixed  Avith it; often even the rupture of
the vessels which pass  through  it,  occasions real hemor-
rhages, and effusions of blood having some analogy with
those  which the same cause  produces in the brain ;  there
is sometimes formed, in consequence of these exudations,
a membrane in the form of a cyst, as in apoplexies.
  Besides,  the resemblance is not  perfect between the
cancerous texture and  that of the  brain, and we ought not
yet to admit the opinion of those who regard these tex-
tures  as identical, and conclude  from it that there is  an
effusion of nervous fluid in the production of the first.


                  IV.  Of Melanosis.

  This production, thus named by M. Laennec, is united
to the  preceding  by J. F. Meckel.   M. Broussais thinks
that it is a tubercular  texture, the black colour of Avhich
is owing to the advanced age of  the individuals who are
the subjects of it;  but it is not  proved that old  people
are the most frequently affected with it.   The same author
makes a more accurate approximation perhaps, bet\ATeen
this colour and that of the membranes  in which the blood 
PRETERNATURAL TEXTURES.
307
has remained for a long time, as in consequence of some
phlegmasias  of long standing.
   Melanosis should be distinguished from the black mat-
ter of the lungs.   The latter, which is  found in most
subjects  after  the  age of from  twelve to fifteen  years,
which increases progressively with age, and which tinges
the bronchial glands, the surface  of the  lungs and the
interstices between the lobules,  does not  constitute a
disease.
   The black colour of this texture  is perfect and entirely
opake ; its consistence is considerable ; and  it  resists ef-
forts  made to tear it.  It accumulates sometimes in masses
of a certain size ; at other times  it forms striae  or plates,
more or less  extensive.  Its interior appears to  be  homo-
geneous ;  no kind of structure is discoverable in it.  This
matter rarely becomes soft; when  this does take place,
there results  from it a sort of black pap or a serous fluid,
mixed with a grumous matter of the same colour.
   Melanosis  is  much more  compatible,  than the  other
morbid textures, with a state of health ; so different is its
nature from that of these textures.   M. Barruel, chief of
the chemical department of the Faculty of Medicine, has
recently examined  for me some melanosis extracted from
a mare, which had a great quantity of it in  the muscles,
in many  viscera and  especially  under the  skin of the
perineum and the  mammae ; it appears from his exami-
nation that melanosis must  be considered as a mass of
matter coloured with blood and  fibrin, both in a peculiar
state, and in  which is found a little albumen, three dis-
tinct  fatty substances, and much of the phosphate of lime
and iron. 
 
ANALYTICAL TABLE  OF CONTENTS.
ADDITIONS TO THE GENERAL OBSERVA-
                    TIONS.
                                                 PAGE
Anatomical Elements.—Attempts have been made to  dis-
  cover what are the primitive elements  of  the tex-
  tures.—Elementary fibre of the ancients.—There are
  three elements ; the cellular, nervous and muscular
  fibre.—The albugineous fibre considered as  a fourth
  element.---Elementary  forms.---Their  division.---
  Opinion of J. F. Meckel.                            16
Classification of Morbid Anatomy.—Method  followed by
  the moderns.—Classification  of Meckel.—Order that
  we shall adopt.                                    22
ADDITIONS  TO THE CELLULAR  SYSTEM.
Adipose Texture.—Names which different authors have
  given to this texture.—External  Forms.—Organiza-
  tion.—Biood Vessels.—Cellular Texture.—Unknown
  Absorbents  and  Nerve*.—The Adipose Texture re-
  sembles the Cellular.—Characters which  distinguish
  them.                                           27 
310
ANALYTICAL TABLE
                                                    PAGE
Chemical JYaiure of the Fat.—It is formed of two princi-
  ples elaine and  stearine.—Their characters.—Means
  of separating  them.—Their proportions  vary.—The
  fat  is fluid in  the living body.—Acids which  the  fat
  furnishes when it is treated with alkalies.              32
Intimate Nature  of the  Cellular  Texture.—The ancients
  appear not to have known this texture.—Authors who
  have  described  it  successively.—Opinion  of  Bordeu
  adopted by some moderns.—Facts upon  which they
  are founded.—It  is to be determined by inspection.      33
MORBID  ANATOMY  OF  THE CELLULAR
                   SYSTEM.
            I. Alterations in the External Forms.

Anasarca.—Fatty  Tumours.—Emphysema.—Hardening
  of the Cellular Texture.—Elephantiasis.              37

            II. Alterations in the Organization.

Phlegmon.—Mode  of adhesion  of  the  divided cellular
  texture.—Cicatrization of  this texture  laid bare.—
  Phenomena that foreign bodies produce in it.—Some-
  times these  bodies remain without producing any in-
  convenience.—Animated foreign bodies.—Osseous and
  cartilaginous transformation.—Fibrous, Serous and Mu-
  eous transformations.—Various degenerations.          38

             III. Alterations in the Development.

Preternatural development.—Membrane of the  fleshy
  granulations.—How it is formed.                      41 
OF CONTENTS.
311
ADDITIONS  TO THE  NERVOUS  SYSTEM  OF
                  ANIMAL LIFE.
Nerves which the Brain furnishes.—The optic nerve does
  not  come from the  brain,  but  from  the  medulla
  oblongata.—The  origin  of the  olfactory is not well
  known.—The olfactory  bulb of  animals.—It  is con-
  tinued with the peduncles of the medulla oblongata.—
  The pulpy portion of the olfactory nerves in  man is
  analogous to it, according to some anatomists.          43
Origin of the Nerves.—They arise  from the grey sub-
  stance.—Arrangement of this substance in the spinal
  marrow.—It  exists also  at the origin of the cerebral
  nerves.—It should be inferred  from this, that it pro-
  duces the nervous substance.                          44
Crossing  of the  Nerves.—It takes place in the medulla
  oblongata.—Consequences in relation to paralysies.     46
Composition of  the Nervous System.—Principles that  M.
  Vauquelin has found in it.—Properties of the two pe-
  culiar fatty substances.—Proportions  of these principles
  in the spinal  marrow  and in the nerves.                47
Texture peculiar to the  Nervous System.—Two substances.
  —White substaace.—The  cerebral  substance  is com-
  posed of fibres.—Method of studying its structure.—
  Course  of those of the  fibres which come from the
  medulla  oblongata.---Fibres of the commissures.---
  Structure of  the  cerebellum.—The substance of the
  nerves has also fibres.—This is likewise the case with
  that of the spinal marrow.—Arrangement of these last.
  —Grey substance.—Its arrangement.—Its structure.—
  The  microscope besides  discovers globules  in the
  nervous  texture.—They resemble those of the blood.
  —Substance  which  secretes them.—Arrangement of
  these globules.—They do not appear to be the seat of
  the colouring matter  in the grey substance.            48
Development of the Nervous Centres.—Various  authors
  have been engaged  with  the  subject.—The  dimen-
  sions of  the cerebrum, cerebellum  and  spinal  marrow-
  are in an inverse proportion at the different  periods of 
312
ANALYTICAL TABLE
  gestation.—Fissure  which divides  all these parts in
  the beginning.—The  conformation of the  cerebrum,
  at first very simple, becomes gradually complicated.—
  Development of the cerebellum, the  cerebral protu-
  berance, and  the spinal  marrow.—Texture  of  the
  encephalon at the different periods.—The  white sub-
  stance appears before  the grey.—Exception, according
  to M. Serres, with regard to  the thalami nervorum op-
  ticorum and the corpora striata.—The vessels precede
  both substances.                                      53
Development of the Nerves.—Period at  which they appear.
  —It is not the same for all.—Development of their tex-
  ture.                                                59
  MORBID, ANATOMY  OF THE NERVOUS SYS-
              TEM  OF ANIMAL  LIFE.

             I. Alterations in the External Forms.

Increase of size in the nerves.—Diminution.—The brain
  diminished in  size.—Softening  of the nerves.—Hard-
  ening  and  softening of the  brain.—Softening of the
  spinal marrow.—Alterations  of situation and form.       GO

             II. Alterations in  the Organization.

Inflammation.—In  the nerves.—In the  brain.—Mode of
  reunion  of the nerves.—Nature  of the  cicatrix.—
  Opinion of Arnemann.—What takes place at the supe-
  rior end in amputations.—Solutions of continuity in
  the  brain and  the  spinal marrow.—Osseous,  fibrous
  and  cartilaginous transformation.—Cysts.—Degenera-
  tions.                                               62

             III. Alterations in  the Development.

Defects of conformation.—Partial and  total  absence.—
  Irregularities of forms.—Congenital  t>ffections.—Ana-
  tomical varieties.—No preternatural  development.      6"> 
OF CONTENTS.
S13
ADDITIONS TO  THE NERVOUS  SYSTEM OF
                 ORGANIC LIFE.
                                                   PAGE
Insulation of the Great Sympathetic.—Opinions of authors
  upon this insulation.—Experiments of Legallois.—Op-
  posite experiments.—Conclusion that must be drawn
  from them.                                        67
Structure of the Ganglions.—They contain the  two sub-
  stances pointed out by Scarpa.—Arrangement of the
  nervous filaments  in  their interior.—Peculiar grey
  substance.—It differs from the cerebral.—It does not
  appear to be changed into fat in fat subjects, as Scarpa
  said.                                              70
Uses of the  Ganglions.—They are of two kinds, accord-
  ing to physiologists.—Idea the most generally admit-
  ted.                                               73
Ganglions of Animals.—The nervous system of the lower
  classes of animals has hardly any analogy with that of
  the superior animals, though many have attempted to
  shew approximations.—What  is called  a ganglion  in
  the former, does not  perhaps deserve that name.—
  In the vertebral animals, the development of the gan-
  glions varies according to many circumstances.        75
ADDITIONS TO  THE VASCULAR SYSTEM
             WITH RED BLOOD.
Situation  of the Arteries.—They are almost everywhere
  situated in the direction of the flexion of the articula-
  tions.—Advantages of this arrangement.—They are in
  general on the internal  side of the limbs.               77
Termination of the Arteries.—Differences in the length of
  their course, in their mode of distribution, their num-
  ber and size, and in the  net-works which their divisions
  form.                                              78
40 
314               ANALYTICAL TABLE
                                                     PAGE
Resistance of the Arteries.—Membranes which support the
   effort, according to the direction in which it is made.—
   Causes  which have an  influence  upon this resistance.
   —Experiments of Wintringham  and Gordon.—Differ-
   ence  between the convex and concave side of the arte-
   rial curves.                                          80
Nature of the Middle Coat of the Arteries.—Reasons alleged
   by those who believe it  muscular.—They are not suf-
   ficient to make us regard it as such.—This coat belongs
   to the yellow fibrous system.                           81
Cellular Membrane  and Sheath of the Arteries.—Characters
   of the cellular membrane.—Arrangement of the cellu-
   lar texture around it.—What should be understood by
   the cellular sheath of the  arteries.—Varieties  which it
   exhibits.—These varieties explain various morbid phe-
   nomena.                                             82
Nerves of the Arteries.—The branches have more of them
   than the trunks.—Mode  of their distribution.            84
Irritability  of  the  Arterial  Texture.—Reasons  assigned
   by those  who admit it.—Experiments  of  Verschuir,
   Bikher, Vanden-Bos, Giulio, Rossi, Home and Thom-
   son.—Other  facts.—Consequences.—The  contraction
   of the arteries is more evident in the small ones.         85
Action of the Arteries in the circulation.—The contraction
   of the arteries  is one of the causes of the  motion of
   the blood.                                            87
Development of the Vascular System.—It is a point  still
   obscure.—Result of  the researches made  upon  the
   chick.—Consequences.                                 88
 MORBID ANATOMY OF THE VASCULAR SYS-
             TEM WITH RED  BLOOD.


            I.  Alterations in the External Forms.

Increase of size of the arteries.—Their growth in length.
  —Their partial dilatation (aneurism).—Their uniform
  dilatation.—Contraction of the arteries.—It may extend 
OF CONTENTS.
315
                                                    PAGE
  to obliteration.—Change in the mode of distribution of
  the arteries, in  consequence of the obliteration of a
  principal trunk.                                      90
             II. Alterations in the Organization.
Inflammation of the  internal membrane.—Obliteration
  which results from it.—Mode of adhesion of the arte-
  rial parietes.—Other terminations of this inflammation.
  —Alterations peculiar to the surrounding cellular tex-
  ture.—Brittleness  from inflammation of the  cellular
  coat.---Peculiar redness  of the internal  membrane
  resembling its inflammation.—Wounds of the  arteries.
  —Results of experiments upon  dogs.—Punctures heal
  perfectly.—In the  more extensive wounds, the termi-
  nation differs according as the cellular sheath is un-
  touched or not.—What takes place in transverse divi-
  sions.—The progress of these wounds is a little differ-
  ent in man.—Solutions of continuity which  affect only
  one part of the  membranes.—Experiments.—In what
  consists the internal mixed aneurism.—Rupture of the
  internal  membranes.—Its  consequences in  different
  cases.—Foreign  bodies  applied to the arteries.—Ossi-
  fication  of the arteries.—Cartilaginous transformation.
  —Fibrous  and   Cellular transformations.—Degenera-
  tions  peculiar to  the arterial  texture.—Fungi.—Ex-
  crescences.—Pultaceous matter.—Common degenera-
  tions.                                               92
             III.  Alterations in the Development.
The varieties of the arteries are numerous.—Some only
  are important in  relation to the circulation.—Preter-
  natural  development of the arteries.                  102
   ADDITIONS  TO THE  VASCULAR  SYSTEM
               WITH BLACK BLOOD.

Venous Valves.—Their number in the different parts.—
  Arrangement of their  edge.—Dilatation of the vein
  where they  are situated.---Their structure.—-Their
  differences.                                        1°3 
316
ANALYTICAL TABLE
                                                    PAGE
Contractility of the Veins.—The veins have a vital action.
  —Facts which  prove it.—Their mode of contraction
  cannot be referred to any other.                     107
Venous Circulation.—Opinion  of Harvey.—Influence  of
  the heart upon this circulation.                      108
Development of the Venous System.—A part of this system
  is developed  before  the arterial.—Doubts in relation
  to the development of the  aorta.—Most of the  veins
  are formed after the  arteries.                       109
 MORBID  ANATOMY OF THE  VASCULAR SYS-
           TEM WITH BLACK  BLOOD.

            I. Alterations in the External Forms.

Dilatation of the veins.—Their contraction.             110

             II.  Alterations in the Organization.

Inflammation.—Cases in which  it is observed.—Effects
  which result from it.—Disorders which it produces.—
  Adhesive  inflammation.—Venous ruptures.—Aneuris-
  mal  varix and  varicose  aneurism.—Osseous transfor-
  mations.—Concretions found in the veins.             111

             III.  Alterations in the Development.

Frequency of anatomical varieties compared with that of
  the arteries.—Preternatural development.             114
  ADDITIONS TO THE  CAPILLARY SYSTEM.

Continuation of the  Arteries with the Veins, Exhalants, fyc.
  —Various opinions of the ancients.—Proofs of the con-
  tinuation of the arteries with the veins.—The continu-
  ation with the exhalants and excretories is less certain.  115 
OF CONTENTS.
317
                                                   PAGE
Erectile Texture.—This texture is  entirely vascular, as
  various anatomists have proved.—Phenomena of which
  it is the seat.—Organs which this texture composes.   116
Capillary Circulation.— Proofs that the heart  has an  in-
  fluence upon it.                                    119
   MORBID  ANATOMY  OF  THE CAPILLARY
                       SYSTEM.

            I. Alterations in the External Forms.
Preternatural growth.                                120
             II.  Alterations in the Organization.
Effects produced by contusion  and concussion.—Wounds.  121
             III. Alterations in the Development.
Preternatural  Development.—Its  mechanism.—Preter-
  natural erectile texture.                             121
  ADDITIONS TO THE EXHALANT  SYSTEM.

Arrangement of the Exhalant Vessels.—Their existence is
  not proved.—There are however  white  vessels.—
  Experiment of Bleuland.—We are ignorant of the mode
  of the termination of these vessels.                  125
  ADDITIONS TO  THE ABSORBENT  SYSTEM.

Origin of the Absorbents.—What is known of this origin.
  —Observation of Cruikshank.—Experiment  of  Mas-
  cagni.—Result of injections.                         127
Venous Absorption.—Termination of the Absorbents.—Dif-
  ferent opinions respecting venous absorption.—Facts
  which prove this absorption.—Consequences.—Obser-
  vation of Abernethy.                               128 
318
ANALYTICAL TABLE
                                                   TAGE
Structure of the Lymphatic Glands.—The opinion rejected
  by Bichat is that of Mascagni and Gordon.—Considera-
  tions in support of this opinion.—Cellular texture,
  veins and nerves of the lymphatic glands.             129
Properties  of the Absorbents.—Sensible  Organic Contrac-
  tility.—Facts which demonstrate this  property.        131
   MORBID ANATOMY OF THE ABSORBENT
                      SYSTEM.

            I. Alterations in the External Forms.

Dilatation of the absorbent vessels.                     132

            II.  Alterations in the Organization.

Inflammation.—Wounds.—Spontaneous ruptures.—Ossifi-
  cation  of the  lymphatic  glands.—Their  tubercular
  affection.                                          132

            III. Alterations in  the Development.

Frequency of anatomical  varieties.—The thoracic duct
  exhibits a great number of them.                     133
    ADDITIONS TO  THE OSSEOUS  SYSTEM.


Intimate Structure of the Bones.—Various  opinions.—Ex-
  amination of the facts in relation to these  opinions.—
  There appear to be in the bones laminae, fibres and
  areolae.                                           135
Arrangement of the Pores of the Compact Texture.          137
Composition of the Osseous Texture.—Analysis of M. Berze-
  lius.—Difference observed by other chemists.—Com-
  position of the bones in an anatomical point of view.    ib.
Veins of the Diploe.—Their arrangement.—They exist in
  different bones.                                     139 
OF CONTENTS.
319
                                                    PAGE
Development of the Osseous System.—Authors  who have
  been particularly engaged with this subject.—All the
  bones are not at first cartilaginous.—Period at which
  the  osseous state  begins in  the different bones.—
  Changes which the  cartilage that is ossified undergoes.
  —Ossification examined in the long and broad bones.—
  Mode of increase in the length of the long bones.—
  Increase in thickness in the  three species of bones.
  —Changes which the cavities of the bones undergo.—
  Other  changes which take place in this system in old
  age.
Second Dentition considered at the period of cutting.—Error
  that should be corrected in all the editions of the work
  of Bichat.                                         145
139
MORBID ANATOMY OF THE OSSEOUS
                  SYSTEM.
            I. Alterations in the External Forms.

Tumours of the bones.—Increase of density of the osse-
  ous texture.—Atrophy of this texture.—Softening.—
  Effect of compression upon the bones.—Changes in the
  natural relations of the bones.—False articulations.     146

             II. Alterations in the Organization.

Suppuration of the bones.—Necrosis.—Reproduction of
  the bones in this affection.—Denudation of the bones.
  —Fractures.---Mechanism of the  formation of the
  callus.—What should be  thought  of the  opinions of
  authors upon  this subject.—Fibrous reunion  of cer-
  tain fractures.—Various  transformations and degene-
  rations.

             III. Alterations in the Development.

Defects of conformation.—Preternatural osseous texture. 155 
320
ANALYTICAL TABLE
 ADDITIONS TO THE MEDULLARY  SYSTEM.

                                                 PAGE
Organization of the Medullary Membrane.—Experiment
  which  renders it  more  conspicuous.---Vessels  and
  nerves  of this membrane.—Adipose vesicles.          157
Sensibility of the Medullary Membrane.                  158
Development.                                       159
Functions.—The marrow  does  not transude in order to
  produce the  synovia.—Other hypothetical uses attri-
  buted to the marrow.—Its trae  functions and those of
  the medullary membrane.                          160
  MORBID ANATOMY OF THE MEDULLARY
                     SYSTEM.

This system  is «o doubt altered in syphilis.—Changes
  which it undergoes in various cases.—Spina ventosa is
  a cancer of the medullary membrane.—Alterations of
  the marrow in phthisical patients.                   161
ADDITIONS TO THE CARTILAGINOUS SYSTEM.

Peculiar Texture.—Its organization is not very apparent.
  —Various opinions.                               163
Chemical Composition.—Results obtained by modern che-
  mists.—Differences according to age.                165
MORBID ANATOMY OF THE  CARTILAGINOUS
                     SYSTEM.

I. Alterations in the External Forms.                    166
            II. Alterations in the Organization.
Inflammation has not  been observed in the cartilages.—
  What takes place when they are  denuded or  broken. 
OF CONTENTS.
321
                                                   PAGE
  —Reproduction of the cartilages.—Osseous transfor-
  mation.                                           167
             III.  Alterations in the Development.

Defects  of  conformation.—Preternatural  cartilaginous
  textures.                                          169
    ADDITIONS TO THE FIBROUS SYSTEM.

Yellow Fibrous Texture.—It  forms a  distinct class in the
  fibrous system.—It is placed wherever a continual re-
  sistance  is required.—Its differences from the white
  fibrous texture.—Its properties.—Its uses.             171
MORBID ANATOMY OF THE FIBROUS SYSTEM.

            I. Alterations in the External Forms.
Thickenings  of  the ligaments  and tendons.—Stiffness
  Avhich they acquire under some circumstances.        173
             II.  Alterations in the Organization.
Inflammation.—Mode of reunion  of divided fibrous or-
  gans.—Ossification rare.—Degenerations.             174
             III. Alterations in the Development.
Relaxation of the ligaments in some defects of conforma-
  tion.—Preternatural fibrous texture.—Fibrous body.    175
 ADDITIONS TO  THE FIBRO-CARTILAGINOUS
                      SYSTEM.

Of the Nature of the Membranous Fibro-cartilages.—They
  are true cartilages.                                 179
Of the Forms of the Fibro-cartilaginous System.—They are
  very various.—Table of this system.                 180
                  41 
322
ANALYTICAL TABLE
  MORBID ANATOMY  OF THE FIBRO-CARTI-
                LAGINOUS  SYSTEM.

                                                    PAGE
I. Alterations in the External Forms.                     182
II. Alterations in the Organization.                        ib.
III.  Alterations in the  Development.—Preternatural  fibro-
  cartilages.                                          183
 ADDITIONS TO THE MUSCULAR  SYSTEM  OF
                   ANIMAL LIFE.

Intimate Structure of the Muscles.—Divisibility of the mus-
  cular fibre.—Size of this fibre.—Inequalities which it
  exhibits on its surface.—Microscopical observations.—
  Is the muscular fibre solid or hollow.                 185
Influence of the Nerves upon Muscular Irritability.—What
  takes place when all the nerves of a muscle are cut.—
  —Consequences.---Many physiologists consider  the
  nerves only as  conductors.—It is difficult to  resolve
  the question in an absolute manner.                  187
Quickness of the Muscular Contractions.—Measure of this
  quickness.—Method of Dr. Wollaston  for estimating it. 190
Size of the Muscles in Contraction.—Causes of error in the
  experiments  made to  determine it.—Observation of
  Erman.                                            191
State of the Circulation in the Muscles in Contraction.—It is
  more rapid according to some physiologists.—Exami-
  nation of the facts upon which  they are founded.—
  This opinion is by no means demonstrated.            192
State of the Muscles after Death.—Stiffness in the dead body.
  —Its causes.—Varieties.—Seat.                      194
 ADDITIONS TO THE  MUSCULAR  SYSTEM  OF
                  ORGANIC LIFE.

Influence of the Nervous System upon the Muscles of Organic
  Life.—It is difficult to determine  it.—Influence of the 
OF CONTENTS.
323
  brain upon  the  contraction of these  muscles.—Influ-
  ence of the spinal marrow and the nerves.             197
Duration of the Organic Contractility.—It varies in different
  muscles.---Order  in which this  property  is  extin-
  guished.                                            200
Force of Dilatation of the Muscles.—Many facts have been
  incorrectly  referred  to  this  force.—Its existence is
  doubtful.                                           201
   MORBID ANATOMY OF  THE MUSCULAR
                       SYSTEM.

            I. Alterations in the External Forms.
Hypertrophy and atrophy.—The pretended fatty degene-
  ration  belongs to this last.—Softening of the  muscles.
  —Effect of  their elongation.—Their shortening  and
  displacement.                                       204
            II. Alterations in the Organization.
Inflammation.—Wounds.—Transformations.             205
             III.  Alterations in the  Development.
Defects  of  conformation.—Preternatural muscular  tex-
  ture.                                               206
    ADDITIONS TO THE MUCOUS SYSTEM.

Villi of the Mucous Membranes.—Forms of these villi seen
  through a  microscope.—Various opinions upon their
  structure.—Upon the termination  of the  lymphatic
  vessels on their summit.—The existence of nerves in
  these villi  is not demonstrated.—Their blood vessels
  and lymphatics are evident.                          209
Mucous Glands.—They are follicles and not properly
  glands.—Their arrangement.—There are simple  and
  compound ones.—Arrangement of these last.—Peculiar
  depressions of the mucous membranes.—Classification
  of the follicles by Home.—Follicular secretion.        212 
324
ANALYTICAL TABLE
                                                    PAGE
Development of the Mucous System.—It is continuous, in
  the first period of conception, with the membranes of
  the ovum.—Development of the intestine in the chick.
  —Applications to man.—Other ideas on this subject.    216
MORBID ANATOMY OF THE MUCOUS SYSTEM.

            I. Alterations in the External Forms.

Dilatation and contraction of the  mucous ducts.—Adhe-
  sions.—Hypertrophy of the mucous membranes.—De-
  fects of situation and form.                           220
             II.  Alterations in the  Organization.
Inflammation.—False membranes.—Cicatrices of the mu-
  cous membranes.—Transformations.—Cancer.         222
             III.  Alterations in the Development.
Their two kinds are distributed unequally in the different
  systems.—Defects of conformation in the mucous sys-
  tem.—Preternatural mucous membranes.           "    223
     ADDITIONS TO THE SEROUS  SYSTEM.

            I. Alterations in the External Forms.
Increase  of nutrition.—It becomes thinner and is dis-
  placed.                                            227
             II.  Alterations in the Organization.
Alterations of the serous fluids in consequence  of inflam-
  mation.—They explain most  of the changes which
  this  affection  produces  in the serous  membranes.—
  Reproduction  of  the serous texture.—Ossification.—
  Various degenerations.                              229
             III. Alterations in the Development.
Defects of conformation.—Preternatural serous  mem-
  branes.—Cysts.—Mode of production of cysts.—Their
  organization.—Substances which they  contain.—How
  they are distinguished from hydatids.                232 
OF CONTENTS.
325
   ADDITIONS  TO THE SYNOVIAL SYSTEM.

                                                    PAGE
Conformation of the  Synovial Membranes.—Proofs  that
  they form sacs without an opening.                  230
Synovial  Fringes.—Their nature and arrangement.—All
  the  synovial membranes have tbem.—Their differ-
  ences,  situation  and uses.—Analogous  fringes in  the
  mucous system.                                    239
Parallel between the Synovial Membranes and the Serous Ones.
  —There are fewer vessels in  the synovial membranes.
  —The structure of these is more distinctly fibrous.—
  They seem to be less extensible.                    241
Existence, Forms and Organization of the Synovial System of
  the Tendons.—This system is gradually confounded with
  the cellular.—Circumstances  which have an influence
  upon the number of the tendinous synovial membranes.
  —Manner of observing these membranes.—Differences
  in their forms, structure, fluid and properties.        242
    MORBID  ANATOMY  OF THE SYNOVIAL
                       SYSTEM.

            I.  Alterations in the External Forms.
Dropsy.—Adhesions.                                 245
             II. Alterations in the Organization.
Different effects of inflammation.—Foreign bodies in the
  articulations.—They exist originally without the syno-
  vial membrane.—Their different  states.—Impressions
  which they sometimes produce.—Peculiar bodies found
  in the  bursae mucosas.—Alterations of the synovial
  membranes in white swellings.                       246
             III. Alterations in the Development.
Preternatural synovial membranes.                     248 
326
ANALYTICAL TABLE
  ADDITIONS TO THE GLANDULAR  SYSTEM.

                                                   PAGE
Intimate Structure of the Glands.—The opposite results ob-
  tained by Ruysh and Malpighi are  owing perhaps only
  to the diversity of the texture of the glands.          249
Influence of the Nerves upon the Action of the Glands.—This
  action is in general but little known.—Difficulty of
  ascertaining the influence  of the nerves.—Experi-
  ments which render it doubtful.                      251
  MORBID ANATOMY OF THE GLANDULAR
                      SYSTEM.

            I. Alterations in the External Forms.
Hypertrophy and atrophy.—Changes  of colour, consist-
  ence and situation.                                  253
             II.  Alterations in the Organization.
Inflammation.—Wounds.—Transformations.              254
            III. Alterations in the Development.
Anatomical varieties.                                  255
   ADDITIONS  TO THE DERMOID SYSTEM.

Colouring Matter.—Mucous Body.—Papillce.---Layers of
  the mucous body.—This body is  not admitted by all
  anatomists.---Experiments  in  order  to obtain the
  colouring matter.—Its mode of production.—It  is in
  circulation  in the skin.—Examination of the other
  parts of the mucous body.—Sanguineous  bunches and
  papillae.—Their  arrangement and structure.           257
Cutaneous Absorption.—Absorption by contact is not de-
  mou3trHted.—Gaseous absorption.                     263
Sebaceous Glands.—Proofs of  their existence.---Their
  structure.                                          266 
OF CONTENTS.
327
    MORBID ANATOMY  OF THE DERMOID
                      SYSTEM.

                                                   PAGE
            I. Alterations in the External Forms.
Changes which the skin  when distended undergoes.—
  Preternatural growth of the different parts of the skin.
  —Horny productions.—Increase of the sebaceous fol-
  licles.—Tumours  which  result from  it.—Cutaneous
  atrophy.—Bunches on the skin and thickening of it.    268
             II. Alterations in the Organization.
Effects produced  by inflammation.—Simple  wounds of
  the skin.—Denudation of the  dermis.—Mucous  and
  cartilaginous transformations.—Cancer.               271
             III. Alterations in the Development.
Defects of conformation.—Preternatural cutaneous tex-
  ture (cicatrix).—Various kinds of cicatrices.—Mecha-
  nism of cicatrization.—Characters of the new cutane-
  ous texture.                                        275
  ADDITIONS TO THE  EPIDERMOID SYSTEM.

Means of Union of the Epidermis with the Dermis.—Exhalant
  and Absorbent Pores.—Nature of the elongations inter-
  mediate  between the  dermis  and the epidermis.—
  Doubts upon the existence  of the pores.              281
Epidermis of the  Mucous Membranes.—It is  not  known
  whether the  deep-seated mucous membranes have an
  epidermis.—Line of  demarcation  apparent  in some
  places between the  superficial and the deep-seated
  mucous membranes.                                284
Nature of the Nails.—They are a dependance of the horny
  layer.—Analogous  parts in animals.—Mode of forma-
  tion of the nails and the horns.—Longitudinal striae of
  the nails.                                          286 
328       ANALYTICAL TABLE OF CONTENTS.
  MORBID  ANATOMY OF THE EPIDERMOID
                      SYSTEM.

                                                  PAGE
Various Alterations of the Epidermis.—Its  destruction.—
  Excrescences of the nails.—Other alterations of the
  nails.—Nail entering the flesh.                      288
     ADDITIONS TO THE  PILOUS SYSTEM.

Structure of the Hairs.—Arrangement of their bulb.—Or-
  ganization.—Body of the hair.—Two opinions upon its
  structure.---Colouring matter of the  hair.---Conse-
  quences.                                          291
MORBID  ANATOMY OF THE PILOUS SYSTEM.

Whiteness.—Alopecia.—Nature of  the  Plica.—Preter-
  natural hairs.                                     295
         PRETERNATURAL TEXTURES.

Their description belongs to general anatomy.—Common
  characters.—General arrangement.—Mode of produc-
  tion.—Differences.                                 299
I. Of Tubercles.—They have  two periods.—1st Period;
  miliary or crude tubercles.—Cyst of the tubercles.—
  2d Period ; softening.—Various terminations.          303
II. Of Scirrhus.---Its  anatomical characters.—Its  varie-
  ties.                                              304
III.  Of Cancer.---Synonyms.---Characters.---Period of
  softening.                                         305
IV.  Of Melanosis.—It differs from the black matter of the
  lungs.—Its distinctive characters.—lis nature.          306
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