THE 
Seat of Formative and Regenerative 
Energy. 
BY 
C. O. WHITMAN. 
Reprinted from the Journal of Morphology, Vol. II., No. 1, July, 1SS8. 
BOSTON: 
GINN AND COMPANY. 
1888. THE 
Seat of Formative and Regenerative 
Energy. 
BY 
C. O. WHITMAN. 
Reprinted from the Journal of Morphology, Vol. II., No. i, July, 1888. 
BOSTON: 
GINN AND COMPANY. 
1888. THE SEAT OF FORMATIVE AND REGENERATIVE 
ENERGY. 
C. O. WHITMAN. 
The question as to the role of the cytoplasm, presents itself 
under two forms: 
1. Is the cytoplasm a passive body, moving only as it is acted 
upon by external forces, or in response to influences emanating 
from the nucleus ? 
2. Or does it behave rather like an organized body, endowed 
with subtle powers of its own, and capable of automatic as well 
as responsive action ? 
There is a strong tendency at the present time to refer all 
kinetic changes in the cytoplasm to the agency of the nucleus, 
and to ascribe to the former the passive role of a nutritive sub- 
stance. The kinetic phenomena of the egg during maturation 
and impregnation have already been considered in their bearing 
on this important question.1 A number of decisive proofs of 
pure nuclear action were pointed out, and at the same time an 
attempt was made to support the opinion that the cytoplasm is 
capable of automatic as well as responsive action. The present 
paper is chiefly devoted to the consideration of phenomena dis- 
played in the cytoplasm, and to the discussion of the question, 
whether the regenerative and formative power of the cell resides 
in the nucleus or in the cytoplasm, or in both taken as a highly 
complex physiological unit. 
The Doctrine of Isotropy. — Pfliiger’s interesting experiments2 
with the amphibian egg to determine the influence of gravitation 
upon the direction of cleavage-planes, led him to conclude that 
the entire egg is “ isotropic.” In other words, to quote from the 
1 Ookinesis. Journ. Morph., I., 2, p. 227, December, 1887. 
2 Ueber den Einfluss der Schwerkraft auf die Theilung der Zellen. Arch.f. d. ges. 
Physiologie, XXXI., pp. 311-318, and XXXII., pp. 1-79. 1883. 28 
WHITMAN. 
[Vol. II. 
author, “ the fertilized egg possesses absolutely no essential rela- 
tion to the later organization of the animal, no more than a snow- 
flake stands in any essential relation to the size and form of the 
avalanche which under certain conditions develops from it. 
That the germ always gives rise to the same form, is due to the 
fact that it is always brought under the same external condi- 
tions.” Immediately after the appearance of Pfluger’s papers, 
it was pointed out by Agassiz and Whitman 3 that, “ if gravita- 
tion were the sole guiding agency in cleavage, its effect ought 
to be instantaneous, and it should be possible to change the 
direction of a cleavage-plane already in progress.” It was also 
shown that the time required to bring about a transposition 
of the third cleavage-plane, suggested a corresponding internal 
transposition of the active protoplasmic matrix of the ovum, in- 
cluding of coiu'se the nuclei,, “ If a body constituted like the 
ovum is restrained by artificial means from taking its normal 
position, a redistribution of material must immediately set in and 
continue until the equilibrium is restored. The active portion 
of the ovum, having a lower specific gravity than the passive 
nutritive elements, would eventually recover its normal position, 
and thus the virtual axis of the ovum would inevitably right 
itself in spite of the viability of the ovum to rotate bodilyA 
Later observations have fully verified these suggestions. 
As now maintained by Born,4 Hertwig,5 Weismann,6 Kolliker,7 
and others, the cytoplasm alone is isotropic, while the nucleus is 
the seat of the directive and form-giving power in development. 
In this modified form, the doctrine of isotropy makes a much 
nearer approach to truth, but I believe that it is far from correct 
in its estimate of the functional importance of the cytoplasm. 
The logical consequences of this view are clearly presented 
by Oscar Hertwig6 (p. 306) in the following words : “Andie 
Kernsubstanz also sind die Krafte gebunden, durch welche die 
3 On the Development of some Pelagic Fish Eggs. Proc. Amer. Acad. Arts dr 
Sciences, XX., p. 40, 1884. 
4 Biolog. Untersuch. Arch. f. mik. Anat., XXIV., 1885. 
6 Das Problem der Befruchtung und der Isotropie des Eies. Jenaische Zeitschrift, 
XVIII., 1885. 
6 Die Continuitat des Keimplasma’s als Grundlage einer Theorie der Vererbung. 
1885. 
7 Die Bedeutung der Zellenkerne fur die Vorgange der Vererbung. Zeitschr. f. 
wiss. Zool., XLII., 1885. No. 1.] 
REGENERATIVE ENERGY. 
29 
organisation des Thieres bestimmt wird. . . . Es erscheint 
gleichgiiltig, ob bei dcr ersten Theilung der eine Kern sich mit der 
sogenannten ammalen, der andere mit der vegetativen Dottersub- 
stanz umhiillt oder ob beide Kerne sich i?i vegetative und animate 
Dottersubstanz in dieser oder jener Weise theilen. . . . Der 
Dotter ist nicht so organisirt, dass aus emer bestimmten Portion 
desselben ein bestimmtes Organ hervorgehen miisste.” It is con- 
ceded (p. 304) that the cytoplasm may have a low grade of 
organization; but it is an organization that changes from 
moment to moment (p. 309), not a “feste Organisation ” bear- 
ing fixed relations to the future organism. 
The opposing view finds the differentiating and formative 
principle either in preformed elements of the cytoplasm (“physi- 
ological molecules” Lankester, “polarized molecules” Pfltiger, 
“ idioplasma ” Nageli), or in a definite organization of the 
cytoplasm itself (Van Beneden and others). “Though the 
substance of a cell,” says Lankester8 (p. 14) “may appear 
homogeneous under the most powerful microscope, excepting 
for the fine granular matter suspended in it, it is quite possible, 
indeed certain, that it may contain already formed and individ- 
ualized\ various kinds of physiological molecules.” And again, 
“The development of one kind of cell from another kind is 
dependent on internal movements of the physiological molecules 
of the protoplasm of such cells.” 
Van Beneden9 has made a thorough study of the struc- 
ture of the egg of Ascaris megalocephala with a view to 
ascertaining if “ les plans de symetrie de l’embryon ne se 
trouvent pas deja preformes dans l’oeuf lui-meme et si l’un des 
traits les plus caracteristiques de 1’organisation de l’espece, 
la symetrie qui la distingue, ne se trouve pas deja indiquee 
dans l’oeuf. L’oeuf d’un animal a symetrie bilaterale au- 
rait-il, comme l’animal dont il provient et qu’il doit devenir, 
une extremite anterieure, une extremite posterieure, une face 
ventrale, une face dorsale, une droite et une gauche ? les 
materiaux qui doivent servir a edifier la moitie droite du 
corps siegent-ils dans la moitie droite de l’oeuf et la substance 
8 Notes on Embryology and Classification. London, 1877. 
9 Recherches sur la maturation de l’oeuf et la Fecondation. Arch, de Biologie, IV., 
2 & 3, 1883. 30 
WHITMAN. 
[Vol. II. 
de la tete ne se trouve-t-elle pas concentree en un point deter- 
mine du corps ovulaire ? ” 
Both views recognize the necessity of assuming that the 
course of ontogenetic development is in some way predeter- 
mined in the egg; but while one finds the force motrice in the 
nucleus, the other would locate it in the cytoplasm. The ad- 
vocates of the former appeal to the so-called isotropy of the 
cytoplasm, to the conspicuous part played by nuclear bodies in 
fecundation and cleavage, to the incapacity for regeneration 
shown by enucleate fragments of infusoria, etc. ; while the sup- 
porters of the latter insist on the constancy of premorphologi- 
cal relations (axial relations, relation of first cleavage-plane to 
the median plane of the future embryo), the remarkable struc- 
tural features exhibited in some eggs, cleavage in planes not 
previously marked by karyokinetic division, etc. The truth 
appears to me to lie on both sides, the error consisting only in 
unduly exaggerating the relative importance of one or the other 
factor. Just now the weight of authority seems to be turning 
in favor of the first view, a result which must be attributed very 
largely to the influence of recent discoveries and theories re- 
specting the nature of fecundation. The question is one of 
such fundamental importance, that it seems desirable to analyze 
closely the facts bearing on the subject. It is for this reason 
that I have dwelt more at length on the movements of the 
germinal vesicle and the pronuclei. 
Especially important is the study of the structure of the egg, 
and the modifications which it undergoes during the period of 
maturation. One of the most important contributions in this 
direction is unquestionably Van Beneden’s great work on Asca- 
ris. No other biologist has yet gone so deeply and thoroughly 
into the subject, nor has any one discussed it with a keener 
appreciation of its theoretical importance. Such well-marked 
structural features as are claimed to exist in this egg are incon- 
sistent with the idea that the cytoplasm is isotropic. 
Polar Rings. — Among the more extraordinary examples of 
cytokinesis may be mentioned the polar rings in the egg of Clep- 
sine, first described by Grube10 (pp. 15-16), and recently more in 
detail by Robin 11 (pp. 97-105) and Whitman 12 (pp. 20-29, 39-41). 
10 Untersuchungen ueber die Entwicklung der Clepsinen. Konigsberg, 1844. 
11 Memoire sur le Developpement embryogenique des Hirudinees. Paris, 1875. 
12 The Embryology of Clepsine. Quart. Jour. Mie. Sci., July, 1878. No. 1.] 
REGENERATIVE ENERGY. 
Although it is by no means certain that the hyaline protoplasm 
of these rings is not in part derived from the germinal vesi- 
cle, it is quite clear that the phenomena are very different 
from the polar phenomena attending the division of the first 
cleavage-nucleus. These remarkable exhibitions of polarity in 
the cytoplasm appear early in the pronuclear stage, and con- 
tinue not only during the centripetal march of the pronuclei but 
even after the first cleavage-nucleus has entered upon its 
kinetic phases of division. Thus we have two distinct scries of 
polar phenomena in progress at the same time, one displaying 
itself in the cytoplasm, the other in the nucleus. We cannot 
suppose that the cytokinetic series is dependent upon the karyo- 
kinetic series for two reasons : first, because the former begins 
earlier than the latter; and second, because such cytokinetic dis- 
plays are unknown in other eggs. The second ground would 
also hold against referring them to pronuclear influences. Al- 
lowing that it may yet be possible to demonstrate that these move- 
ments originate in response to pronuclear influence, it would 
still be very difficult to believe that they are sustained through- 
out by the continuous action of the same agency. It would be 
altogether more probable, as a little reflection will show, that 
the movements once started are capable of maintaining them- 
selves, independently of the inciting cause.* 
Cytokinetic Phenomena. — The cytoplasm exhibits a great vari- 
ety of changes and conditions, variously described as ‘polar 
concentration,’ ‘ radiating bands,’ ‘ waves of contraction,’ ‘ zonal 
constrictions,’ ‘automatic cortical layer,’ ‘amoeboid movements,’ 
‘phases of segregation,’ ‘astral radiations,’ ‘rhythmic contrac- 
tility,’ ‘migratory movements,’ ‘crown of folds’ (Faltenkranz), 
‘ autonomic movements ’ (rotation, circulation, pulsation), etc. 
While some of these phenomena might, with considerable 
reason, be claimed as purely cytokinetic, most of them are so 
intimately associated with karyokinetic activity that they must 
be explained, either as the direct result of the latter, or as the 
effect of impulses generated by the interaction of nucleus and 
* The polar and parapolar circles described by Van Beneden (No. 9) in the egg of 
Ascaris, are not comparable with the polar rings of Clepsine. For the ‘ disque 
polaire’ arises before, and disappears with, the penetration of the spermatozoon; 
the polar rings (Clepsine), on the contrary, appear after the penetration of the 
spermatozoon, and are not wholly dissipated until after the completion of the first 
cleavage. 32 
WHITMAN. 
[Vol. II. 
cytoplasm. The hypothesis of reciprocal action is not incom- 
patible with the opinion that the conditions of this action are 
furnished, in the first instance, if not continuously, by changes 
of a chemical or molecular nature, which arise quite indepen- 
dently, either in one factor alone, or in both. The source of 
the initiatory impulse would still be an open question. Our 
knowledge of the phenomena above designated is too incom- 
plete to furnish a key to the solution of this problem. For 
the purpose we have in view, it will be sufficient, therefore, to 
refer to a few of the more important examples, in which each 
factor may be supposed to play a more or less important part, 
deferring the discussion of the main question until we come to 
consider phenomena of a more decisive nature. 
Following the penetration of the spermatozoon into the 
ovum, various forms of contraction in the vitellus have been 
observed; and these are generally regarded as the effect of 
impulses generated by the spermatic element. The usual 
sequence of events certainly accords very well with this view, 
but there are one or two facts which should make us hesitate to 
accept it. In some aquatic animals, in which the sexual cells 
unite before ovipositing, the time of these contractions bears 
no constant relation to the time of union, but does bear such a 
relation to the time of contact of the egg with water, whether 
this contact be brought about artificially or in the natural 
course of events. Still another cogent reason for not ascribing 
these contractions to the independent action of the male pro- 
nucleus is found in the fact that similar, though more sluggish, 
movements may, in some well ascertained cases, be induced by 
placing unfertilised eggs in water. The most general of these 
movements is the flattening of the pole, and the gradual con- 
traction of the whole vitelline sphere, resulting in the forma- 
tion of a perivitelline space. 
The Constriction Attending the Exit of the Polar Globules. — 
The flattening of the pole is attended, or followed, in some cases, 
with a very remarkable constriction, which, beginning in the 
equatorial zone, travels towards the animal pole, finishing up with 
a nipple-like protuberance, from which the first polar globule is 
expelled. The exit of the second polar globule is sometimes pre- 
ceded by a similar but weaker constriction. This constriction 
has been observed (No. 12, p. 18) in the eggs of different species No. 1.] 
REGENERATIVE ENERGY. 
33 
of Clepsine ; and the same, or a closely analogous constriction, 
has been described by Kupffer and Benecke13 (p. 19) in the egg 
of Petromyzon, and by Ransom 14 (pp. 463, 464, 477, 479) in the 
egg of the Stickleback and some other fresh-water teleosts. 
This constriction has been confounded by the last mentioned 
authors with yolk-contraction, and brought into connection with 
the formation of the perivitelline space (‘ breathing-chamber ’ of 
Ransom, * Eiraum ’ of Kupffer and Benecke). This space prob- 
ably results from contraction of the vitellus as well as from 
expansion of the egg membrane, but the constriction is a 
special act of the vitellus to expel the polar globule. The elim- 
ination of polar globules is thus a process involving co-op- 
erant actions of both factors; and if the part performed by 
the polar amphiaster is karyokinetic, the associated act of the 
vitellus may be characterized as cytokinetic. I have before 
referred to the centrifugal movement of the germinal vesicle 
as an instance of repellant action, and I regard this constriction 
as a part of the same action. It is thus a phenomenon of 
maturation, not of impregnation. 
Ransom, as well as Kupffer and Benecke, explains the phe- 
nomenon as a result of the penetration of the spermatozoon, 
and hence has failed to distinguish it from other phenomena of 
a similar, though not identical, nature. Bearing this fact in 
mind, we are enabled to find in their descriptions — especially 
that of Ransom — an exact parallel of the special constriction 
which always accompanies the formation of polar globules in 
Clepsine. Ransom’s account is extremely interesting, and has 
attracted so little attention from later embryologists, that it 
seems worth while to introduce a portion of it here. After 
stating that slow contractions begin from the first moment of 
entry of the spermatozoa, causing first a flattening of the ger- 
minal pole, and afterwards slight changes of outline due to 
‘ travelling waves ’ at other parts of the surface, he proceeds as 
follows : — 
“ Gradually more vivid contractions commence, at various 
times after fecundation, according to the temperature. In warm 
weather they have been noted in six minutes, in cooler weather 
13 Der Vorgang der Befruchtung am Eie der Neunaugen. Konigsberg, 1878. 
14 Observations on the Ovum of Osseous Fishes. Proc. Roy. Soc. London, 
VII., 1856. 34 
WHITMAN. 
[Vol. II. 
in fifteen or twenty minutes after impregnation. They cause a 
flattening of one side of the yolk-ball, to see which it is often 
necessary to roll the egg over. The flat surface gradually be- 
comes a sulcus, giving a reniform outline to the yolk. It then 
extends all round, giving rise to a dumbbell shape. This sulcus, 
which may be termed equatorial, travels with considerable but 
variable rapidity towards the germinal pole, producing as it passes 
on, the flask form. The sulcus is lost by passing forwards to the 
germinal pole, not by relaxation. It is seen for a brief space 
affecting the thickness of the germinal disc only, to which it gives 
a nipple-like form, while the food-yolk is round. When effaced, 
the whole yolk-ball is globular and at rest, the germinal disc being 
110 longer prominent. This series of forms recurs with more or 
less of regularity, and with some variations both of time and 
form, about fifteen or twenty times, each series being the result 
of a travelling wave" (No. 14, pp. 463-464). 
Had Ransom succeeded in connecting the formation of polar 
globules with the more regular and prominent ‘wave,’ which he 
has so vividly described, he would doubtless have seen the neces- 
sity of distinguishing this wave from the movements which 
follow it, precisely as Kupffer and Benecke distinguished in 
the egg of Petromyzon a ‘ zonal constriction ’ which invariably 
accompanies the appearance of the second polar globule. They 
did not succeed in tracing the origin of the first polar globule; 
but they have described a constriction (p. 15) around the ger- 
minal pole (Fig. 7, /), which appears immediately after the sper- 
matozoa come into contact with the egg; and this, I would 
suggest, may have the same relation to the first polar globule 
that the ‘ zonal constriction ’ has to the second. 
Polar Aggregation. — In the formation of the germinal disc 
of many pelagic fish ova, we meet with very remarkable cyto- 
plasmic movements. In the fresh-laid egg, the germinal proto- 
plasm forms a cortical layer of uniform thickness around the yolk. 
But this condition lasts only for a few seconds, during which the 
spermatozoon finds an entrance into the egg. This event is 
followed at once by a polar concentration of the peripheral layer 
of protoplasm, which results in the gradual formation of the 
germinal disc with its centrally placed pronuclei. 
Is it in one or both of the pronuclear bodies that we are to 
look for the cause of the polar aggregation of protoplasm ? Is No. 1.] 
REGENERATIVE ENERGY. 
35 
the protoplasm a passive mass, moved at the expense of nuclear 
energy alone, or has it motor energy of its own ? In the latter 
case, are the conditions necessary to action supplied by the 
nuclei or by the protoplasm, or by both ? Although we are yet 
a long way from a solution of these questions, it may be possi- 
ble to show that the protoplasm is an active rather than a pas- 
sive factor in the movements we are considering. Any view 
which represents the germinal protoplasm as a passive body, 
moving only as it is impelled by nuclear forces, appears to me 
irreconcilable with the following facts : — 
I. In most meroblastic vertebrate ova (including those of 
many teleostei), the germinal disc is already formed before fec- 
undation takes place. The male pronucleus cannot therefore 
be a necessary factor in the formation of this disc. 
2. In many pelagic fish ova, where the disc forms after fecun- 
dation, the polar amphiaster is formed before polar concentra- 
tion begins. The cause of concentration cannot therefore, in 
this case, be referred to the centrifugal movement of the 
germinal vesicle, nor to any changes which this body undergoes 
prior to the formation of the polar amphiaster. 
If this conclusion holds equally in the first class of eggs, we 
are fully warranted in affirming that the germinal disc forms 
independently, not only of the male pronucleus, but also of the 
germinal vesicle and its derivatives, since in these eggs the disc 
is formed before fecundation and before the polar amphiaster 
divides. 
The validity of these conclusions may be disputed by those 
who hold with Weismann (No. 6, pp. 90-122) that the two pronu- 
clei are identical in their molecular structure, and that both act 
alike upon the protoplasm, but in proportion to their mass. It 
might be argued that a definite quantity of karyoplasm (‘ Keim- 
plasm ’) is requisite in order to concentrate the protoplasm in 
the form of a polar disc. If the mass of the germinal vesicle, 
or of its pronuclear elements, be large enough, it would form a 
•germinal disc without the aid of the male pronucleus; if it fall 
short of the requisite mass-measure, it would have to be reinforced 
by the male pronucleus before it could accomplish the work. It 
will be time to accept this view when it has been shown that 
there are such quantitative relations as the theory postulates. 
Such an explanation of the disc-formation would take no account 36 
WHITMAN. 
[Vol. II. 
of the polarity of the egg, and would leave inexplicable the differ- 
ence between telolecithal and controlecithal eggs. Besides, this 
view assumes that the pronuclei are homodynamous, a point 
which cannot be conceded, since male pronuclei do not behave 
towards one another as they do towards female pronuclei. 
A special feature in the polarity of the fish egg, noticed by 
Kupffer15 and by Hoffman16 (p. 88), is the formation of a tem- 
porary discoidal thickening (‘ Gegenhiigel,’ Kupffer) at the veg- 
etal pole. Here, then, is a disc-formation at the point farthest 
removed from the nuclear bodies, and this fact appears to be 
fatal to the above theory. We are reminded of the rings in the 
egg of Clepsine, and their concentration into two polar discs. 
It appears not improbable that the two sets of phenomena are 
similar in nature, and determined by like forces. In the fish 
egg the disc-formation is not preceded by a ring-formation ; and 
the nearest approach to the ring-rays are the ‘ radiating bands ’ 
or ‘beaded streams’ described by Ryder17 (p. 17). 
Raffaele (Mitth. d. Zool. Station z. Neapel, VIII., 1, 1888) has 
recently described a very singular phenomenon in the egg of 
Labrax. The egg has a single large oil globule at the pole op- 
posite the germinal disc. This oil globule is enveloped with 
protoplasm, which, on the side facing the germ, thickens up 
until it takes the form of a long club-shaped body. This body 
elongates in an axial direction, and the distal portion, which is 
gradually constricted off, eventually assumes a globular form 
and rests on the inner face of the germ. Ryder has noticed 
protoplasmic bodies in the egg of Gadus (‘ segmenting corpus- 
cles’) which, as Raffaele suggests, may have a similar mode of 
origin. It occurs to me that this body of protoplasm may cor- 
respond to Kupffer’s ‘ Gegenhiigel,’ and that it is diverted 
from its usual peripheral track by the presence of the oil globule. 
The Artificial Division of Infusoria. — The artificial divis- 
ion of infusoria has been resorted to as a means of decid- 
ing, experimentally, the question of the relative importance 
of the nucleus. M. Nussbaum18 was the first to establish 
15 Die Entwickelung des Herings im Ei. Jahresb. d. Comm. z. zviss. Unter- 
suchung der deutschen Meere in Kiel, IV.-VI., 1874-1876. 
16 Zur Ontogenie der Knochenfische. Amsterdam, 1881. 
17 The Embryography of Osseous Fishes. Report of the Commissioner of Fish 
and Fisheries for 1882. 
18 Die spontane und kiinstliche Theilung der Infusorien. Arch.f mik. Anat., No. r.J 
REGENERATIVE ENERGY. 
the general fact, that enucleate pieces of an infusorium are 
incapable of regenerating lost parts, while nucleate pieces soon 
regain the specific form. “ The nucleus is thus indispensa- 
ble to the preservation of the formative energy of the cell.” Gru- 
ber,19 whose experiments were begun at about the same time as 
those of Nussbaum, has reached the same general result. But 
one of Gruber’s experiments, which was at first supposed to 
show that regeneration is possible without the presence of a 
nucleus, brings out a fact of considerable importance. A Stentor 
cceruleus was selected, in which spontaneous fission had already 
begun, as indicated by the concentration of the rosary-formed 
nucleus into a simple oval form, and by the beginning of a new 
peristome at the middle of the body. A transverse section was 
made just in front of the new peristome, and so close upon the 
nucleus that it nearly all escaped from the cut surface of the 
posterior half of the Stentor. The anterior portion retained 
no part of the nucleus. The two parts were isolated, and on the 
following day each was found to have become a complete Sten- 
tor. As the plane of division was nearly the same as that which 
would have been followed if the process of spontaneous fission 
had not been interfered with, Gruber (No. 19, p. 13) finally con- 
cludes, contrary to his first interpretation, that this was not a case 
of regeneration, but of reproduction. The process of reproduc- 
tion once initiated by nuclear action may go on, so he thinks, to 
completion without further assistance from the nucleus. He 
insists, however, that the first impulse to division is given by 
the nucleus, since in all cases where artificial division is executed 
before the process of spontaneous fission begins, enucleate parts 
are incapable of regeneration. While finding no reason to doubt 
the accuracy of Gruber’s observations, I must contend that they 
do not warrant the conclusion so forcibly stated in the following 
words: “ Auf rein empirischen Wege werden wir hier vor die 
unumstossliche Thatsache gestellt, dass der Kern der wich- 
tigste, dass er der arterhaltende Bestandtheil der Zelle ist” (No. 
19, p. 16). Allowing that regeneration is impossible in the ab- 
sence of a nucleus, that is no proof that the nucleus is the sole 
seat of regenerative power, nor is it a proof that the nucleus is 
XXVI., January, 1886, p. 485. Cf. also Sitz-Ber. d. Niederrh. Ges. f Natur- u. 
Heilkunde, 1884, p. 262. 
19 Beitrage zur Kenntniss der Physiologie und Biologie der Protozoen. Berichtt 
d. Naturforsch. Ges. zu Freiburg, I., H. 2, 1886. Also Biolog. Centralbl., IV., p. 
717, and V., p. 137. 38 
WHITMAN. 
[Vol. 11. 
a more important factor than the cytoplasm. There is not a 
single observation to prove what is so confidently asserted, that 
the nucleus gives the * Anstoss ’ to division. This may be so 
and it may not. The observations prove, (1) that, in some of 
the higher Protozoa, the whole process of reproduction by fssion, 
with exception of the initiatory steps, may be accomplished inde- 
pendently of nuclear action; and (2) that the initiatory steps 
cannot take place if the nucleus and the cytoplasm are artificially 
separated. The whole truth is well stated by Nussbaum (No. 18, 
p. 516) : “Kern und Protoplasma sind nur vereint lebensfahig: 
beide sterben isolirt nach kurzerer oder langerer Zeit ab.” It 
is clearly impossible therefore, by any such experiments as 
Gruber has carried out, to settle the question of the precise 
locus of the regenerative energy. 
On general theoretical grounds, as well as by the fact that 
enucleate forms are found among the Protista, we are compelled 
to accept the generally received view, that the nucleus is sec- 
ondary in origin. It may be true, as suggested by Gruber20 
(p. 151), that these so-called enucleate forms contain nuclear 
substance in solution, and that the first step in the phylogeny 
of the nucleus consisted in the formation of scattered granules, 
the coalescence of which would give rise to the single nucleus. 
But it is hardly necessary to add that we do not see how this 
(or any other) mode of explaining the origin of the nucleus as a 
secondary body can be brought into harmony with the idea that 
it embodies the whole regenerative energy of the cell. 
Interesting and instructive as are these experiments in the 
artificial division of the higher Protozoa, they do not alone fur- 
nish a satisfactory basis for general conclusions. They require 
to be supplemented by similar experiments on the simpler forms 
of Protozoa, and by much more complete observations than have 
yet appeared on the normal processes of fission and coalescence 
exhibited in the Heliozoa. In proof of this we have only to 
refer to Gruber’s own observations on Actinophrys sol21 (pp. 63- 
67) and Actinosphcerium eichhornii 22 (pp. 381-382). Actinophrys 
20 Ueber Kern und Kerntheilung bei den Protozoen. Zeitschr. f. wiss. Zool.t 
XL., i, p. 121. 
21 Untersuchunge nueber einige Protozoen. Zeitschr. f wiss. Zool., XXXVIII., 
p. 45, 1883. Also Zool. Anzeiger, No. 118, 1882, p. 423. 
22 Ueber Kerntheilungsvorgange bei einigen Protozoen. Zeitschr. f. wiss. Zool. 
XXXVIII., p. 372, 1883. No. 1.] 
REGENERATIVE ENERGY. 
39 
is capable of breaking up into parts without the concurrence of 
any visible changes in the nucleus. The enucleate individuals — 
if such they are entitled to be called — may agree perfectly with 
the nucleate individual in outward form and behavior. They 
live and grow, and coalesce not only with one another, but with 
the nucleate form. Whether they are capable of generating a 
nucleus or not was not ascertained. The multinucleate Actin- 
osphcerium breaks up in a similar manner without the inter- 
vention of the karyokinetic process; but here the individual 
parts generally contain one or more of the original nuclei. Two 
or more individuals may coalesce, but the coalescence extends 
only to the cytoplasm, the number of nuclei being the sum of 
those contained in the separate individuals before fusion. These 
remarkable facts appear to bear out Gruber’s conclusion : “That 
the nucleus has no importance for those functions of the cell 
which do not stand in direct relation to reproduction; such as 
locomotion (pseudopod-formation), inception of food, excretion 
(pulsation of contractile vacuoles), and growth. Even on the ex- 
ternal form it may be without influence ” (No. 21, p. 66). Gruber 
(No. 19, p. 12) still maintains the accuracy of this view in every 
particular except that relating to the influence of the nucleus on 
the form of the cytoplasm. He now holds, in common with 
Weismann, Hertwig, Kolliker, Strasburger, and many other 
German biologists, that the form-creating and form-conserving 
principle is confined to the nucleus. How, when, or where the 
nucleus manifests its form-moulding power remains a mystery; 
but that it gives the first impulse to the regenerative act must be 
inferred — so the argument runs — from the fact that the 
violent separation of nucleus and cytoplasm destroys the re- 
generative power in all cases, except where the process of 
reproduction is begun before separation is executed. This is 
the focal point of the question with which we set out. 
Aside from experiments in the artificial separation of nucleus 
and protoplasm, the principal arguments in support of this view 
are drawn from the phenomena of fecundation and cleavage, and 
are involved with certain theories of heredity which cannot be 
dealt with here. The observations of Gruber on Actinophrys 
and Actinosphcerium, if the phenomena are not of a pathological 
nature,—and such an interpretation seems to be precluded,— 
should certainly make us hesitate to ascribe all the form-regu- 40 
WHITMAN. 
[Vol. II. 
lating power ot the cell to the nucleus. This reserve is ren- 
dered imperative by other facts yet to be mentioned, for one of 
which we are again indebted to Gruber23 (p. 221). In summing 
up the results of his “ Studies on Amoebae,” he states, “ that 
two very closely related species of Amoeba may have quite unlike- 
formed nuclei; while species differing widely in external form 
may have quite similar nuclei.” Plainly this is the contrary of 
what might be expected if the formative power lay exclusively 
in the nucleus. 
No Form-Correlation between Nucleus and Cytoplasm. — It 
may be put down as an indisputable fact that no form- 
correlation exists between nucleus and cytoplasm. Except dur- 
ing the process of division, the nucleus seldom departs from its 
typical spherical form. It divides and subdivides, ever repeat- 
ing the same steps and ever returning to the same round or oval 
form. So far as can be seen, its influence upon the cytoplasm 
is equal in all directions; and hence it would seem that its 
formative power, if it have any, could only contribute to the 
maintenance of the spherical form of the cytoplasm. How dif- 
ferent with the cell! It preserves the spherical form as rarely 
as the nucleus departs from it. Variation in form marks the 
beginning and the end of every important chapter in its history. 
While the nucleus repeats over and over again its little cycle 
of form-changes with mechanical regularity, the cell marches 
straight on from form to form, never returning, and never re- 
peating, differentiating, developing, and adapting itself at every 
step to its environment and to the work it is destined to per- 
form. From the egg onward through all the stages of histo- 
genesis and form-evolution, we search in vain for a single inti- 
mation anywhere that either the form of the organism or the 
forms of the individual cells are moulded by direct nuclear in- 
fluence. At the beginning of any ontogenetic series, when we 
get the most rapid and vivid displays of nuclear energy, we 
see that the environment of each cell is much more potent in 
determining its form than the nucleus. True, certain conditions 
of the environment may be said to be largely the result of 
nuclear activity; and to this extent the nucleus may be said to 
determine, indirectly, the form of the cell. But this is very dif- 
ferent from saying that the nucleus has a direct controlling 
23 “Studien iiber Amoeben.” Zeitschr.f. wiss. Zool., XLI., p. 186,1884. No. 1.] 
REGENERATIVE ENERGY. 
power over the specific form of the cell, as claimed by Gruber, 
Weismann, and others. When the end of the ontogenetic series 
is reached, we find the reproductive power of the nucleus greatly 
diminished, and its influence over the form of the cell propor- 
tionally reduced. Indeed, in the majority of cases the form of 
the cell now appears to be maintained entirely independently of 
the nucleus, and whatever modification of form the latter ex- 
hibits appears to be the result of mechanical pressure. The 
form of the nucleus is now determined by that of the cell rather 
than the reverse. 
If we study the more varied form-changes of the nucleus 
which occur in the life-cycle of one of the higher Protozoa, we 
are struck with the fact that the external form of the infusorium 
is, to all appearance, completely independent of what transpires 
in the nucleus. A single nucleus may divide a hundred times 
or more without the slightest effect on the form of the infuso- 
rium. The products of these many divisions may undergo vari- 
ous changes of form, and ultimately coalesce to form a single 
nucleus, and yet no change of form in the cytoplasm. The 
multinucleated form may break up into parts, some without, 
others with one or more nuclei, and the enucleate, uninucleate, 
and plurinucleate individuals all agree in presenting the same 
specific form. The nucleus may pass from the oval form to 
that of a long rosary; then, after a period of vegetative life on 
the part of the cytoplasm, return to the original oval form, and 
undergo the regular changes of division, the whole cycle of 
transformations coming to a conclusion without producing any 
discernible effect on the cytoplasm beyond that of simple fis- 
sion. Each part carries with it the power to resume at once 
the form which characterized the original whole. The nucleus 
gives no evidence at any time of holding the formative power; 
but we have seen from Gruber’s experiment on Stentor, above 
referred to, that the cytoplasm does exercise this power, and 
that it does so even in the absence of a nucleus. 
Gruber does not attempt to deny this; but he thinks it nec- 
essary to assume that the power exhibited by the cytoplasm in 
the case mentioned, was communicated to it in the form of 
molecular motion, the original impulse being given by the nu- 
cleus. As we have seen, there is nothing in his experiments 
which makes such a conclusion necessary, and the burden of 
proof properly falls to him who makes the assumption. 42 
WHITMAN. 
[Vol. II. 
One needs only reverse the case to see the illogical nature of 
the position. Let us suppose that it has been ascertained by 
numerous experiments that the nucleus of an infusorium is in- 
capable of karyokinetic division when separated from the cyto- 
plasm, except in those cases where the division is already in 
progress at the time of separation. Would there be anything 
either in the general rule or in these exceptional cases, from 
which to conclude that the performances of the nucleus are first 
set in motion by some impulse from the cytoplasm ? Would 
the incapacity of the nucleus to divide when placed in abnor- 
mal conditions demonstrate its inability to divide autonomically 
under normal conditions ? If artificial isolation were found 
insufficient to arrest a series of complex movements already 
begun in the nucleus, would the death of the nucleus, shortly 
after the completion of these movements, furnish any ground for 
denying that they were automatic ? These questions appear to 
present the matter in a just light, and to carry with them their 
own answers. The point would hardly seem to deserve the 
attention given it, were it not for the great importance of 
the question under consideration, and the fact that we are 
dealing with the opinion of a high authority, — an opinion for 
which experimental evidence of a crucial nature is claimed, 
and an opinion fully indorsed by so eminent a thinker as Weis- 
mann. 
Schneider s Experiment. — Schneider’s 24 (p. 509) experiment 
with Thalassicolla, although not affording any decisive evidence 
as to the precise location of the formative power, is yet of some 
interest in this connection. The extracapsular or cortical pro- 
toplasm was removed, leaving the central capsule free. At the 
end of twelve hours the whole surface of the capsule showed 
delicate pseudopodial extensions, and soon after appeared a dis- 
tinct extra-capsular layer (“ matrix ” of the pseudopodial rays), 
which gradually grew to normal thickness. The experiment was 
repeated three times in succession on the same individual, and 
each time with the same result. The extra-capsular envelope 
gave no evidence of sharing the regenerative power, but died 
shortly after isolation. This envelope, according to Brandt25 
24 Zur Kenntniss des Baues der Radiolarien. Mill. Arch. 1867, p. 509. 
25 Koloniebildende Radiolarien (Sphaerozoeen). Fauna und Florad es Golfes 
von Neapel. XIII. Monographic, 1885. No. 1.1 
REGENERATIVE ENERGY. 
43 
(p. 84) takes no share whatever in the production of spores ; 
and thus it appears that the central capsule is the seat of the 
reproductive as well as the regenerative energy. During “ vege- 
tative life ” the various functions (digestion, locomotion, sensa- 
tion, etc.) all appear to be performed by the extra-capsular 
cytoplasm ; but the whole functional activity, as supposed by 
Brandt, is under the regulative influence of the central capsule. 
In the Sphasrozoa colonies the division of labor is carried still 
farther; for while the pseudopodial rays have their special func- 
tions, certain definite areas of the matrix (“ Klumpen von As- 
similationsplasma ”) provide for the digestion of the starch 
granules which are produced by symbiotic algae; and different 
layers or zones are distinguishable even in the central capsule. 
That there should be such a complete separation of functions 
between the central core and the cortical layer of the same body 
of cytoplasm is no less instructive than it is remarkable. It is a 
capital illustration of the possibilities of organization and the 
physiological division of labor without any corresponding divis- 
ion into distinct morphological units. 
Recent studies tend to show that the only important sub- 
stance conveyed into the egg by the spermatozoon is that which 
takes the form of the male pronucleus. The unavoidable con- 
clusion would appear to be that the pronuclei are the sole 
bearers of hereditary tendencies. This is unquestionably a 
point of cardinal importance, and it furnishes the strongest 
argument that has yet been advanced in favor of regarding the 
nucleus as the seat of the formative power. This side of the 
question could not be fairly dealt with within the limits of 
the present paper, as it would lead to a consideration of the 
whole problem of heredity. It is my purpose, however, to re- 
turn to this subject at no very distant date. 
The Idea of a Formative Power. — Let us now consider 
whether any rational basis can be found for the idea of a 
formative power as a resultant from, and an expression of, 
physiological unity. I am fully conscious that the subject is 
one of profound mystery, the solution of which appears to 
lie as far beyond our grasp to-day as at any time in the 
past. We draw nearer to the problem, but the effect is rather 
to enhance than to reduce its apparent magnitude. Every step 
in advance only brings us to a keener sense of the subtle and 44 
WHITMAN. 
[Vol. II. 
incomprehensible nature of the force or forces contemplated. 
We see the effects only imperfectly, and are baffled in every 
attempt to understand the mode of action. For the present we 
must be content to search for the direction in which answers 
lie ; and herein is found the chief value of theories. 
The more important speculations on this subject have 
taken the form of theories of heredity. In most of these 
theories, at least those of recent date, we find a fundamental 
idea which must be accepted as true ; namely, that the sexual 
cells reflect in some way in their chemico-physiological con- 
stitution all the typical structural features of the parent- 
organism. How all the hereditary tendencies can be contained 
in a single cell, and with such completeness that the developing 
organism repeats step for step the chief form-phases of a genea- 
logical history stretching through countless myriads of genera- 
tions, back from the present into the very dawn of life, and 
ultimately unfolds every detail of structure and feature of the 
parent-organism, is a mystery that transcends our understand- 
ing. The preformationists of last century took refuge in the 
celebrated inclusion (Einschachtelung, emboitement) theory, 
which made the real mystery unapproachable by hiding it be- 
hind an endless series of miracles. The triumph of the epigene- 
sists brought with it the reclamation of the problem, but left 
us with the indefinable vis essentialis of Wolff, the nisus forma- 
tivus of Blumenbach. In more recent times we have seen vari- 
ous metaphysical hypotheses of extra-organic agents or forces 
supplanted by physiological hypotheses which seek the cause of 
the phenomena in intra-organic forces. But the reaction which 
followed the fierce struggles with vitalism has left its impression 
on most of the theories now in vogue. Biological problems 
have been brought more and more under the influence of 
mechanical conceptions, which regard all phenomena from an 
objective standpoint. Science has vindicated this method, and 
as a method it is unassailable. It is no less indispensable to 
research in the organic than in the inorganic world; but the 
biologist is reminded at every turn that the method is not ex- 
haustive, and from the nature of the case it never can be. The 
biologist does not hesitate to follow the shibboleth of “ molecu- 
lar motion ” to its final goal, but he must beware of being 
blinded by any artifice of method to distinctions which lie No. i.] 
REGENERATIVE ENERGY. 
45 
beyond it. He accepts the authority of the chemist and the 
physicist for the fact that the primary elements of the organism 
are identical with those found in inorganic matter, and with 
them repudiates the notion that life is “ a force having no con- 
nection with primary energy or motion.” But no one disputes 
the fact that the living organism represents special combinations 
of matter and force, and displays phenomena which find no 
parallel in non-living matter. Hence it does not appear at all 
irrational to conclude that vital phenomena are the manifesta- 
tions of special forces, resultants of course, and yet quite unlike 
the elementary forces from which they are derived. 
If from the same elements by different chemical combina- 
tions, we get new substances, differing widely inter se in their 
chemico-physical constitution, and totally unlike their primary 
constituents, then why not new forces in the same way ? The 
chemist and the physicist agree in referring the differences of 
substances to a dynamical cause, and their mechanical concep- 
tions do not prevent, but compel them to ascribe a specific 
energy to each different atom and molecule. In spite of the 
tendency of physical thought to regard “ all matter as one and 
all energy as one,” chemistry and physics are built up on the 
assumption that chemical elements are unlike, and that in dif- 
ferent modes of combination is given the basis for that infinite 
variety of substances with which we meet. If the primary 
energy is in each case called by the same name, “ polarity,” it 
is nevertheless understood that these polarities are as unlike as 
the elements which manifest them. It is just here that we see 
the foundation for those qualitative distinctions which, in the 
mind of the biologist, must ever overshadow in importance the 
physicist’s factors of quantity and motion. 
All physical explanations, no less than biological, lead ulti- 
mately to the conception of intrinsic forces. The chemist’s 
unit, like the physicist’s, is the embodiment of energy. From 
a comparatively few atom-energies an endless number of mole- 
cule-energies are built up; these aggregate in units of a higher 
order, some statical, others dynamical; and so on through what 
Nageli calls micella and micellar aggregates, until we arrive 
at the living cell. In this ascending series each new aggregate 
represents a unit, the individuality of the parts being merged 
in that of the whole. The grounds for distinguishing various 46 
WHITMAN. 
[Vol. II. 
organic, physiological, and biological units, are thus of the same 
general nature as those which compel us to discriminate be- 
tween physical and chemical units. Of course these higher 
units combine both atomic and molecular structure; but they 
have superadded to, and including this, a structure as a whole, 
which is entirely ignored in the expression “ molecular aggre- 
gates.” As they result from the union, not of simple or com- 
plex molecules, but of complex molecular groups, their structure 
may be said to be at least as widely separated from the mole- 
cule as this is from the atom. The power which such a unit 
represents as a whole is not the same as the powers represented 
by its constituent elements when uncombined, nor is it the sum 
of these several powers. Derived from them, and yet wholly 
unlike them, as water is something totally unlike its chemical 
elements or any simple mechanical addition of these elements. 
It is precisely this point which is so persistently ignored in 
all so-called physico-chemical theories of heredity. And yet 
all analysis and all observation leads to the conclusion, that 
molecular structure is not directly responsible for vital phe- 
nomena. In claiming that “physiological units” have some- 
thing higher than molecular structure and power, I am not 
treading on ultra-scientific ground, but following the course 
already sanctioned by chemistry and physics, and the only 
one which can ever reconcile physico-chemical and biological 
conceptions. 
Admit — what no one denies — that a molecule is totally 
unlike its constituent elements, that its energy is unlike that of 
its atoms, taken individually or collectively ; and further, that 
simple molecules, without losing their structural integrity, may 
unite to form complex molecules, and we have only to carry the 
same process a few steps farther to reach those units whose in- 
tegral structure is no longer adequately described as molecular. 
If analysis fails to discover a physiological bond which is capable 
of binding molecular aggregates into units of the vital order, 
its failure must be attributed to imperfection of methods, for 
observation bears constant and unvarying testimony to its ex- 
istence. If analysis and observation combine to show that 
whatever force an organism expends is the correlate and equiva- 
lent of force taken into it, and if chemical and physical pro- 
cesses underlie all vital phenomena, it does not by any means No. i.] 
REGENERATIVE ENERGY. 
4 7 
follow that there is any identity between vital activity and 
physico-chemical forces. The power which causes chemical 
elements to combine is not identical with the power which 
results from their combination ; nor is the power which breaks 
down a chemical compound identical with the powers of its 
separate elements. 
The views here enunciated are not contradicted by the long- 
established fact, that the laws which regulate the formation of 
chemical compounds are the same for both organic and inor- 
ganic bodies. The position taken does not affirm that organic 
compounds differ from inorganic either in material constituents, 
or in the forces which hold these constituents together. What 
we do affirm is this : We cannot stop with the most complex 
molecules revealed or revealable by chemical or physical re- 
search ; we must pass from organic to living, organized matter, 
not by the supervention of new laws, but by ultra-chemico- 
physical, or chemico-organic combinations, which are absolutely 
beyond the highest possibilities of chemical analysis. Inability 
to define these higher modes of combination is no reason for 
doubting the testimony of all our senses to their existence. 
And why should we expect chemical research to bring any 
positive confirmation of their reality, when all chemical analysis 
presupposes conditions which are the absolute negation of vital 
conditions ? Does self-stultification ever become more complete 
than in the assumption that vital forces and conditions are dis- 
coverable precisely there where they confessedly do not exist ? 
Or is it rational to conclude that, because vital conditions have 
arisen from non-vital, the exclusive study of the latter will reveal 
the former ? So long as the chemist’s methods debar him from 
the study of physiological modes of aggregation will he be im- 
potent to divine the links which connect molecular motion with 
sensibility, and just so long will “physiological chemistry” 
remain a delusive misnomer. 
A complex aggregate of atoms, so bound together by mutual 
affinities as to represent a physical unit, possessing, as a whole, 
properties and powers derived from but unlike those of its con- 
stituent elements, and existing by virtue of, and only during the 
maintenance of, the chemical connexus of these elements, is a 
conception which may be carried straight forward up to the 
cell. The living cell may be regarded as a system of very com- 48 
WHITMAN. 
[Vol. II. 
plex chemico-organic units, bound together by subtle chemico- 
physiological bonds, and displaying in their collective capacity 
functions and powers which are entirely foreign to them as 
individual and isolated elements, and which are therefore indis- 
solubly identified with the physiological connexus or consensus. 
Vague and unsatisfactory as such a view may appear, and 
as the best possible view must be from the limitations of our 
knowledge, it may yet contribute something towards a clearer 
conception of what we have called the formative power of the 
cell. It will be sufficiently clear now that we have not in mind 
a phantom-form which, like a mould, impresses its shape upon 
plastic material; but a power which represents the resultant of 
the consentient reactions of indwelling forces. Such a power 
declares itself in every living organism and in every developing 
germ. 
The action of the formative power has often been likened to 
the architectural power displayed in crystallization ; and if the 
essential distinctions are kept in view, such a comparison is 
justified by one or two very instructive analogies. If the physi- 
cist is not compelled to recognize a special crystallizing force, 
he is at least unable to deny that a crystalline aggregate reacts 
upon the parts in such a manner as to determine the direction 
of that marvellous “constructive power” with which the mole- 
cules are endowed. When we see a crystal reproduce its lost 
apex ; or, as in the oft-cited experiment of Lavalle, an angle of 
an octohedral crystal spontaneously replaced by a surface, as 
the result of an artificially produced surface at the correspond- 
ing angle, we have no alternative but to infer a physical correla- 
tion of parts, under the influence of which the direction of forces 
is determined. So in the development of a germ, in the repair 
of injured parts, and in the regeneration of lost parts, the fact 
is irresistibly forced upon us, that the organism as a whole con- 
trols the formative processes going on in each part. The forma- 
tive power then belongs only to the organism as a physiological 
whole ; and it does not represent a sum or aggregate of atomic, 
molecular, or other forces, but results from special combinations 
of ultra-molecular units, and disappears as such the moment the 
physiological connexus is destroyed. 
This idea may appear, at first sight, to stand in contradiction 
with the fact that parts of an organism, resulting from sponta- No. i.] 
REGENERATIVE ENERGY. 
49 
neous or artificial division, possess the same formative power as 
did the undivided organism. But it must be remembered that 
most organisms do not admit of such division, and that in those 
that do admit of it, everything depends on how the division is 
made. The extra-capsular portion of a Radiolarian does not 
reproduce the central capsule, nor does the non-nucleated frag- 
ment of an infusorian regain its lost parts. Even here, then, it 
is not permissible to disregard the physiological correlation of 
parts, since both nuclear and cytoplasmic elements are indis- 
pensable to the preservation of the formative power. We still 
have to regard such organisms as physiological wholes, although 
the physiological connexus may be representable in aliquot 
parts. 
The principle holds true of every organism, irrespective of 
whether the mass is divided into cells or not. The fact that 
physiological unity is not broken by cell-boundaries is confirmed 
in so many ways that it must be accepted as one of the funda- 
mental truths of biology.