THE SHATTUCK LECTURE. 
THE RANGE AND SIGNIFICANCE OE 
VARIATION IN THE HUMAN 
SKELETON. 
By THOMAS DWIGHT, M.D., LL.D. 
PARKMAN PROFF.SSOR OF ANATOMY AT HARVART1 UNIVERSITY. THE SHATTUOK LECTURE. 
THE RANGE AND SIGNIFICANCE OF 
VARIATION IN THE HUMAN 
SKELETON. 
By THOMAS DWIGHT, M.D., LL.D. 
PAHKMAN PKOFESSOK OF ANATOMY AT HARVARD UNIVH.RSITY. 
Road at the Annual Meeting of the Massachusetts Medical Society, 
June 12, 1894. 
BOSTON: 
PRESS OF DAVID CLAPP & SON. 
1894. THE RANGE AND SIGNIFICANCE OF VARIA- 
TION IN THE HUMAN SKELETON. 
In 1878 an essay on the Identification of the Human 
Skeleton had the good fortune to receive the Shattuck Prize 
offered by the Massachusetts Medical Society. It is fitting 
that the same line of thought should be developed in the 
Shattuck Lecture. 
In that essay were discussed the recognition of the sex 
and age of the skeleton, the method of estimating the height 
and of making proper allowance for such parts as might be 
wanting. To some of these questions I brought methods 
of my own, but for many points I was forced to rely on 
the statements in books, too often quoted one from another. 
No part of medical literature is so perfunctory, artificial, 
and altogether unsatisfactory as medico-legal anatomy. 
During my professorship at the Harvard Medical School 
I have tried to use the material for original investigations, 
to find new criteria of sex and of age, to observe the degree 
of asymmetry between the two sides of the body, to learn 
how frequently anomalies occur which would vitiate the 
usual methods of procedure, and finally to study the ques- 
tion of the relation between the external shape of the body, 
its peculiar individuality, and the shape of the supporting 
framework. Though, as I hope to show, these researches 
have not been fruitless, yet some of these fields have yielded 
little. Attempts have exceeded performances. But if the 
man is to be pitied who can travel from Dan to Beersheba 
and cry " ’Tis all barren !” much more is the anatomist worthy 
of compassion whose studies in the dissecting-room show 4 
TIIE RANGE AND SIGNIFICANCE OF 
him nothing but dry details of the structure of the body. 
It is his own fault if he brings no fresh learning to the 
great topics of the day. In these studies I have seen many 
luminous facts throwing; lig-ht on the relations of the bodies 
© © 
of man and lower animals, on the peculiarities of prehis- 
toric man, and on the process of development and growth. 
I shall not leave these quite without notice ; but, speaking 
as I am to a medical audience, rendering as it were an 
account of my stewardship (for what is a professor in a 
Medical School but the trusted servant of the profession?), 
I shall bring into strongest relief those parts of the inquiry 
which are of most practical value in medico-legal questions, 
It would require a course of lectures, rather than a single 
one, to follow the steps of my investigations. I wish as 
much as may be to spare my audience the details, giving 
only the results. I shall not, however, confine myself 
exclusively to my own work, as it is my purpose to show 
the present state of our knowledge. 
In living nature each species suggests a more or less ideal 
type, the exact counterpart of which the student often 
searches for in vain. This type is not the expression of 
the mean development; it is far above that. It is the per- 
fect individual. It is what in a show of animals or plants 
would be called a "prize-winner.” It is in such a speci- 
men that we would study the relative development of the 
different parts. We shall never reach this by compiling 
the means of vast numbers of specimens. This latter 
method, however, if exercised with due care and discretion, 
will give us, not the type of the animal or plant as shown 
at its best, but the one most commonly met with. These 
two conceptions must not be confounded, for they are two 
different things, each of which has its place and its uses. 
When we come to Man, one ideal type is not enough. 
We should have to take each race by itself, were it not 
that I am dealing with the Caucasian alone. The differ- VARIATION IN THE HUMAN SKELETON. 
5 
once caused by sex, however, requires one type for man 
and another for woman. Indeed, it may be said in paren- 
thesis that this shows admirably the difference between the 
ideal and the average. What sort of a human figure would 
be reached by an average of measurements of males and 
females ? This principle hereafter with advancing science 
must be carried even further, so as to recognize sub-types 
such as the tall, the short and the intermediate. 
But nature shows the student more than the type and 
the mean. It even disguises them by numberless varia- 
tions in many, often in opposite, directions. 
The Sex. 
Turning at length to the human skeleton, we find as in 
the whole body, two types, a male and a female. The 
typical skeleton reveals its sex so distinctly that none but 
a tyro would need measure and compass to find it. But 
to the anatomist there are many signs which to others are 
unknown, by which almost every bone in the body reveals 
its sex. This is not to say that it is always easy or even 
possible to decide on the sex of a skeleton. Far from it. 
We are confronted here with the effect of variation. The 
mean male or female skeleton is of course less easily recog- 
nized than the typical one. Then come those which have 
fewer and fewer characteristic points, till we find a certain 
number of which the diagnosis is very difficult or even im- 
possible. My studies have been specially directed to these 
cases, among which we may reckon skeletons of which the 
most characteristic parts are wanting. 
The sex has always been determined by the pelvis. 1 
can reiterate my remark of sixteen years ago, that it is for 
that purpose of more value than all the rest of the skele- 
ton. There is little or nothing to add. 
The female pelvis is broad and the male deep. These 
remarks apply, however, chiefly to the true pelvis. There 6 
THE RANGE AND SIGNIFICANCE OF 
is some discrepancy in the statements, as to the transverse 
measurements of the false pelvis. While I believe it is 
true that as a rule the anterior superior spines of the ilia 
are farther apart in woman, I question very much whether 
this is true of the most distant points of the iliac crest. 
Should the pelvis be wanting or too little typical to be con- 
clusive, for such there are, we must turn to the general 
sexual characteristics of bone, which indeed will help us 
with the pelvis itself. 
There is the male and female type of bone, there are the 
proportions of the body (which, however, are not of much 
use if the bones are separate), and there are the peculiari- 
ties of each bone. Of course the spheres of these different 
criteria fuse, one with another. 
First, as to the general male and female characteristics. 
We all know that male bones are larger, stronger and more 
curved. Their ridges and projections are greater and 
rougher. It seems to be tacitly assumed that, excepting 
the mere size, these features depend on the greater muscu- 
lar development of man. This I do not believe is the fact, 
at all events among civilized races. My observations go 
to show that female bones rarely assume the male develop- 
ment. I never find, even in the strongest, the same rough 
surfaces and ridges, rarely the same thickness. There is 
one sign which has received little attention and which re- 
pays research. It is the small size of the female articular 
surfaces. I shall return to this again and again, for it is 
of the greatest significance, and, as all the bones have 
joints, of the widest application. 
Next, as to the proportions of the figure. The small 
thorax, both short and narrow, is essentially female. While 
it is true that the lumbar region of the spine is relatively 
longer in woman, the chief factors in the shortness of the 
thorax are the short sternum and small lower ribs. Add 
to this the relatively slight development of the upper ex- VARIATION IN TIIE HUMAN SKEUETON. 
7 
t realities, and we arc ready for the study of the individual 
bones. 
The sex of the skull is very often fairly easy to deter- 
mine. The relatively small size of the face, the lightness 
of the jaws, the small size of the superciliary eminences, 
of the occipital protuberance and ridges, and of the mastoid 
processes of the female are very suggestive. One feature, 
which I think of much value, is the more sudden change 
of direction from the forehead to the top of the skull in 
woman. Another, which we owe to Professor Cleland, is 
the more marked elevation above the occipital condyles in 
man, which throws the face higher up, departing more from 
the infantile condition which lingers in woman, as is shown 
by the more prominent frontal and parietal eminences. 
As a specimen of the male skull I show one which its late 
occupant would have been glad to have so used,—that of 
Spurzheim, the phrenologist. 
The studies which I have undertaken on bones of the 
trunk and limbs must be given at some length. In my 
previous essay I had discussed on the basis of a very small 
number of observations of the sternum, the value of Hyrtl’s 
law that " the manubrium of the female sternum exceeds 
half the length of the body, while the body of the male 
sternum is, at least, twice as long as the manubrium.” I 
found then, curiously enough, that the averages of my 
measurements confirmed that law, but that the exceptions 
were equal to the eases in accord with it. More curiously 
still, I found this result repeated in a series of measurements 
large enough to be satisfactory (those of 228 bones), with 
the difference that the exceptions amounted to almost pre- 
cisely 40%. Thus, though the law still held true in aver- 
ages, it would fail to apply to two bodies out of five, and 
thus would be useless for the determination of any particu- 
lar case. Farther, as yet unpublished, observations have 
raised my numbers to 842 sterna, of which 222 were male 8 
THE RANGE AND SIGNIFICANCE OF 
and 120 female. My results once more confirm Hyrtl’s 
law for the mean, but still approximately forty per cent, 
of the cases are exceptions, owing to the variability of this 
bone. 
Strauch found in addition that in male and female sterna 
of equal length, the former is narrower in the manubrium 
and in the lower part of the body. According to him the 
female sternum is relatively (but not absolutely) broader 
than the male one. Hence we conclude that though aver- 
ages may deceive us, yet it is possible to recognize very 
distinctly a male and a female type of breast-bone. The 
former with a relatively long and regular body, the lower 
parts of which are well developed, separating the attach- 
ments of the lower cartilages, the latter with a shorter 
body, broadened below and having depressions of the lower 
cartilages close together, indicating a want of development 
of the lower sternebrae. Intermediate forms of difficult 
diagnosis must occur. In these I should look for relatively 
large or small clavicular facets as signs of male or female 
sterna respectively. Here are more or less peculiar speci- 
mens. In this, which happens to come from a negress, 
the body ends opposite the fourth or fifth cartilage. 
The separate bones of the spine and ribs offer little that 
is of practical value. 
The whole upper extremity is much lighter in woman. 
The lighter shoulders rest on a smaller and relatively nar- 
rower thorax. The collar-bones are very characteristic. 
Strong, long, and boldly curved in man, they are slight, 
short and straighter in woman, 'flic degree of curve is 
less characteristic than some other features, as we some- 
times find slight but strongly curved clavicles in woman 
and strong straight ones in man. This depends on tin* pe- 
culiarities of the figure. The largeness or smallness of the 
articular surfaces is of much importance. 
The Shoulder Blade is an extremely variable bone. VARIATION IN THE HUMAN SKELETON. 
9 
To me it is very interesting. I imagine that I shall sur- 
prise my hearers in speaking of its sexual characteristics as 
very remarkable. The scapular index, that is the ratio of 
the breadth to the length, need not be discussed, though I 
have measured 198 bones for this paper. Its sexual signi- 
ficance is practically nil. In a previous paper I have given 
drawings of two widely different scapuhe with almost iden- 
tical indices. 
While it is very difficult to state what, beyond small size 
and delicacy of build, constitute the sexual characteristics 
of the female scapula, yet there is no question that in well 
marked cases it has a characteristic type. In my opinion 
a competent expert can decide with great probability the 
sex of the scapula in at least four out of five of a consider- 
able number of bones taken at random. 
The mere question of size is an important one. I have 
examined the bones of 123 bodies, 84 male and 39 female, 
in which the height and breadth of shoulders were known, 
and have taken the length , hr eadth and index. By far the 
most useful of these measurements is that of the length, 
as shown in the following table : 
Length of Scapula. 
Male. Female. 
Length of Bone. Number. Number. 
From 13 to 14 cm. 10 
“ 14 “ 15 “ 3 13 
“ 15 “ 16 “ 10 11 
“ lb “ 17 “ 32 5 
“ 17 “ 18 “ 30 
“ 18 “ 19 “ 8 
“ 19 “ 20 “ 1 
Average length of male bone, 1G.8 cm. 
“ 14 44 female bone, 14.7 cm. 
As the two sides usually differ, I have in this series 
always taken the longer bone. 10 
THE RANGE AND SIGNIFICANCE OF 
Thus it appears that of 123 bones 26 measure less than 
15 cm., of which only 3 were male ; also that 76 measure 
16 cm. or more, of which only 5 were female. There is 
no single instance of a bone measuring less than 14 cm. 
being male, nor of one measuring 17 being female. It is 
needless to say that exceptions would be found in a very 
large series, but these limits are very valuable. 
I have studied the dimensions and proportions of the 
glenoid cavity on 90 bones, of which 63 were male and 
27 female. In brief, the female socket is not only smaller 
but relatively narrower. The average male length is 3.92 
cm., and the female 3.36. Very few male sockets are less 
than 3.6 cm., and very few female ones as long. 
When it comes to examining the various parts of the 
bone, one by one, it is very difficult to find sexual charac- 
teristics that will stand rigid examination; none the less I 
have little difficulty in defining a typical female scapula. 
It is more easy to do so than to define a male one, as 
the latter is more variable. The greatest length should 
not exceed 15. cm., and that of the glenoid should be about 
3.4. The latter should look narrow and delicate. The 
inferior angle is sharp, the posterior border straight as far 
as the spine, its upper portion inclining forward. The up- 
per border shows a sharp descent from the superior angle 
to the supra-scapular notch. The process for the teres 
major at the lower end of the axillary border is small. 
The coracoid is remarkably delicate, its end is compressed 
instead of knobbed. The acromion is narrow, of the shape 
called falcate by Prof. Macalister. In the male the lower 
angle is broader, the teres major process more developed. 
The posterior border is rather more rounded, the upper 
border more horizontal and higher, so as to make a larger 
supra-spinous fossa, the coracoid is thick with an ap- 
proach to a knob at the end. The acromion larger, 
squarer, with a large clavicular facet. VARIATION IN THE HUMAN SKELETON. 
11 
In view of’ the considerable difference in size already 
mentioned, it is plain that the sex of most shoulder-blades 
may he determined by that alone beyond reasonable doubt. 
Many bones, however, are of the doubtful size. These, in 
my opinion, can for the most part be sorted out by an ex- 
pert. A small residue is not to be recognized. A bone 
the sex of which cannot be told is more likely to be male 
than female. We may feel reasonably sure that it does 
not belong to a tall man or a short woman. There are 
exceptions to all rules. Here is a female scapula which 
both in size and shape is distinctly masculine, yet it came 
from a short and fat old woman with a short neck and high 
shoulders. It is perhaps relevant to state that she was in- 
sane ; as it is thought that structural peculiaries arc often 
found in the deranged. 
The female humerus, radius and ulna show far more 
strikingly what I have called the general femininity of their 
structure, than the bones of the thigh and leg. Though 
I do not in this case speak by the book, that is by measure- 
ments, I believe that the difference of size is greater be- 
tween male and female humeri than between the femora. 
It is generally thought that the female humerus is more 
slanting than the male, that is to say makes a smaller lat- 
eral angle with the extended and supinated fore-arm, but 
Berteaux’s measurements make the difference too slight to 
he worth much. The articular ends of bone of both arm 
and fore-arm come to the rescue, but I regret that I have 
no series of measurements large enough to quote. 
The Femuii has rightly received much attention. It 
is a favorite of anatomists. I have, therefore, the advan- 
tage of valuable observations of others to compare with my 
own. I may in particular refer to the works of Humphry, 
Broca, Mikulicz, Charpy and Berteaux. The monograph 
of the last on the humerus and the femur is a mine of 
information. Leaving aside the length of the femur, let 
us take certain parts. 12 
TIIE RANGE AND SIGNIFICANCE OF 
My observations on these details are founded on 64 
cases, 38 men and 2(5 women, in which the body was 
measured before dissection and the bones studied in detail 
later. The length of the neck of the femur is on the whole 
in direct ratio to the length of the shaft. That of woman 
is therefore on the average the shorter, but there is no re- 
lative sexual difference worth noting. Berteaux has shown 
moreover that the relation of the thickness of the neck to 
its vertical breadth is the same in the two sexes. The 
angle which it makes with the shaft has long been a moot 
point. It has been taught that it is less (that is to say 
nearer a right angle) in shorter femurs, and if a short femur 
joins a broad pelvis, as in woman, by so much the more 
is the angle decreased and thus the angle is smaller in 
woman. This is diagrammatic demonstration which I long 
taught with perfect good faith. Of late years, however, it 
has been disputed by several observers, some even maintain- 
ing the reverse. My own observations, taken with others, 
convince me that there is probably no sexual significance in 
the angle (with one reservation to be presently set forth). 
The average in the two sexes is about the same, that of the 
women being indeed in my series a trifle the greater, thus 
in men 125.1°, in women 125.6°. Like every one else I 
find that there is a great individual variation, ranging from 
110° to 144°. Be it noted by the way that the lowest is 
in a man and the highest is in a woman. But in the male 
bones there seems to be no regularity in the distribution of 
these variations. In man a long or a short femur is about 
equally likely to have a large or a small angle ; but the 
shorter female ones tend to a lower angle. There is, there- 
fore, this much truth in the old idea, that the shortest, but 
but I do not say the most typical, female femurs have 
angles below the average, as proved by the following ob- 
servations. The average angle of the longer half of the 
male bones is 126.5°, and that of the shorter 123.6°, VARIATION IN THE HUMAN SKELETON. 
13 
while the longer and the shorter halves of the female series 
give 129.2°, and 121.9° respectively. It appears also that 
the highest angles of all are in the longest female femurs, 
but I doubt whether this connection is so regular as that of 
the short ones. This shows, however, that as a whole this 
angle is of little value as a sign of sex. 
Another angle which has been thought to have more or 
less significance is that of the shaft with a vertical line, which 
according to the old theory should also be greater in short- 
er bones and wider pelves, and therefore associated with a 
smaller cervical angle. An analysis of my tables shows 
no system of relation between these angles. On the other 
hand the average inclination is a little less in the male than 
in the female, being 9.3° and 10.(5° respectively. This is 
too small to be of any practical value, especially as the in- 
dividual variation is very great. 
Some other measurements seem to throw more light on 
this matter. They tend to establish the theory that the 
small size of joints is characteristic of woman. They are 
the greatest diameter of the head of the femur and the 
greatest transverse breadth through the condyles. The 
average diameter of the male head is 4.8 cm., that of the 
female 4.15. My tables show one marked difference be- 
tween the sexes ; namely, that in the women there is a fair- 
ly regular increase in the size of the head corresponding 
with the increase in length of the femur. Among the men 
this is not so. While it is true that most of the largest 
heads are found in the longer half of the bones and most of 
the smallest in the shorter half, the correspondence is far 
less evident. 1 find, moreover, that but two of the male 
hones have a diameter of less than 4.5 cm. and but two of 
the female a greater. Both these female bones were among 
the longest, but the two male were but a little below the 
average. Thus it would seem that the actual measurement 
of the head of the femur is a pretty good criterion of the 14 
THE liANGE AND SIGNIFICANCE OF 
sex. The measurements of the knee are less conclusive. 
The average difference is just under one centimetre (8.3 
and 7.3), but there are more that overlap. 
Moreover there is a peculiarity in the shape of the typi- 
cal male and female thigh bones which defies mathematical 
statement, which indeed I found very difficult to define 
long after I was aware of its presence. It is not merely 
that the typical female bone is more slender, as in fact 
everybody knows, but that seen from the front it has a 
peculiar outline. The shaft narrows gradually from the 
condyles till at, or above its middle, a part is reached that is 
narrower than elsewhere, above which there is a much less 
evident expansion. The typical male bone narrows much 
more suddenly from the condyles, so that the stout shaft 
soon reaches a tolerably uniform thickness. A rear view 
shows more distinctly that the male peculiarity seems to de- 
pend on the greater lateral projection of the outer condyle. 
Exceptions are plenty, but for all that there seems to be a 
pretty distinct difference of type, which with the help of cer- 
tain measurements should enable us to determine the sex 
in most cases. I may mention that with the exception of a 
third trochanter (of the true kind) peculiar forms of femur 
are almost always male. 
The tibia is in many respects a very variable bone. 
Asa rule its greater delicacy of structure in woman is very 
plain. The smallness of the articular surfaces is striking. 
It is easy for an expert to judge rightly of its sex in most 
cases, though beyond the signs mentioned there is nothing 
absolutely characteristic. 
While it appears from this discussion that there are certain 
mathematical considerations of great value in determining 
the sex, I would say emphatically that I consider the intel- 
ligent familarity with bones which develops what might al- 
most be called an instinct, more trustworthy than hard and 
fast rules, resting on the dreary accuracy of statistics. VARIATION IN TIIE HUMAN SKELETON. 
15 
I have here bones from two widely different bodies which 
arc interesting in this connection. One was an uncom- 
monly good, even a graceful, figure of a young woman, 
were it not that the shoulders were somewhat too square 
and heavy. flic bones are all remarkably graceful, though 
rather strong. The femur has the characteristic female 
outline. In spite of the comparatively heavy shoulders the 
scapulae and humeri are distinctly feminine. The other 
was one of the largest and most powerful looking female 
bodies I ever dissected, except that the hands and feet 
were small. She had been a factory hand. The femur 
is an uncommonly powerful bone for a woman, but the 
small head, as well as its outline, suggests the sex. The 
bones of the upper extremity are evidently female. The 
slight development of the shoulders in women is therefore 
a recognizable feature in the bones. Contrast the bones of 
this large woman with those of a slight young man, of 
whom more later. 
Tiie Age. 
The diagnosis of the age of bones (children not being 
considered) resolves itself into the study of processes oc- 
curring at three periods : first, that of late adolescence and 
early maturity ; second, that of mature and middle life ; and 
third, that of advanced age. 
For the first period our guides are chiefly the union 
of the epiphyses, and that having occurred, the condition 
of the line of junction. I have not had the opportunity 
of making extensive observations at this age, but it is 
remarkable that so far as they go they all point one 
way, namely, to the earlier union of distinct parts than ac- 
cords with the general teaching, and to the speedy disap- 
pearance of the epiphysial lines. 
I agree with Topinard in looking on our knowledge as 
very unsatisfactory, but I cannot accept his provisional 16 
THE RANGE AND SIGNIFICANCE OF 
table, which to my mind puts the dates of union much too 
late. The following table, giving the time of union of the 
epiphyses of the long bones compiled from English anato- 
mies, is much better, but still wrong in the same direction. 
From 16 to 18 lower epiphyses of humerus (except in- 
ternal condyle) upper ends of radius and ulna, lesser tro- 
chanter of femur. 
At 18 internal condyle of humerus, great trochanter. 
At 18 to 19 head of femur, lower end of tibia. 
From 20 to 21 or 22 head of humerus, lower end of 
radius and ulna, condyles of femur, lower end of fibula, 
upper end of tibia. 
From 22 to 24 upper end of fibula. 
My observations on a comparatively small number allow 
me to offer the following as a provisional chart from 17 on. 
At 17 things are much as described as from 16 to 18, 
but perhaps a little more advanced. The lower end of the 
humerus is joined, excepting possibly the inner condyle. 
Subsequently the process is more rapid, so that the 
epiphyses of the long bones are usually firmly joined to the 
shaft at 19. At this age the lines of union about the 
elbow and hip and ankle are nearly gone. At 20 all are 
indistinct or quite wanting. As for other parts, the basilar 
process of the occipital joins the sphenoid at the surface at 
from 17 to 19, the suture inside the skull being usually 
closed by 17. Once at 19 I saw the internal suture closed, 
but not the lower, and on section found a considerable 
piece of cartilage intervening. In another of the same age, 
which, however, was not split, there was no trace of a 
suture. The union of the pieces of the sacrum may be 
nearly finished at 17. The epiphyses of the crests of the 
ilia and of the posterior border and inferior angle of the 
scapula are among the last to unite. They probably join 
at about 21, but the lines of the crests of the ilia may be 
seen in parts for some years. As Topinard remarks, in- VARIATION IN THE HUMAN SKELETON. 
17 
dividual variations are many. I have several bones from 
a male skeleton which would seem much younger than 
those of others of both sexes of the same age. The fact is 
that this hoy of 19, whose bones correspond very well with 
the usual statements, is the most backward specimen 1 re- 
member. I think it is pretty certain that in the female the 
process is completed earlier. I do not agree with Topi- 
nard that it is completed earlier in the lower than in the 
upper extremity. 
As I have had occasion to point out, the statements as 
to the time of the union of the different parts of the body 
of the sternum found in most text books are very far from 
correct, apparently having been copied and rceopied. I 
am glad to find a great modification in the recent editions 
of the leading English anatomies. The union of the four 
pieces of the body begins from below, the fourth joining 
the third by 15 years or earlier. The union of the other 
parts of the body is completed by the age of 20. I have 
seen it completed at 16£ and at 19 (but not always). In 
a girl of 17 I have found the first piece of the body distinct, 
the others being united. I cannot distinctly remember 
ever having seen the body of the sternum of a white in 
more than one piece after 20, but once in a man of 46 the 
union of the first and second pieces of the meso-sternum 
had but just begun. 
For the long succeeding period from maturity to marked 
decline three chief criteria may be considered, namely : first, 
the union of the different pieces of the sternum and the 
progress of ossification of the ensiform cartilage ; second, the 
closure of the cranial sutures ; and third, the co-ossification 
of the horns of the hyoid with the body. 
The sternum having reached its normal condition of three 
pieces at 20 (and probably often earlier), the next change 
is the appearance of ossification in the ensiform cartilage, 
which may after this occur at any time and is no indication 18 
THE RANGE AND SIGNIFICANCE OF 
of even middle age. This condition of affairs, namely, a 
meso-sternum in one piece, a distinct manubrium and 
ensiform, the latter more or less bony, usually persists 
throughout life. It exceeds fifty per cent, of my observa- 
vations on about 150 bodies. As these were on the aver- 
age much above middle age, it is probable that this condi- 
tion is even more common. In many eases the ensiform 
becomes one with the body. Though more frequent after 
middle age than before it, this is a sign of little value, for 
it is hard to say when this occurs. It rarely, however, be- 
gins before thirty. Union of all three pieces into one piece 
of bone is uncommon, occurring in less than 10%. This 
condition is probably dependent on constitutional tendency 
rather than on age, for in most of the cases which I have 
seen it apparently occurred before 50. I have met with it 
at 25 and at 28. Union of the manubrium and body with a 
free ensiform is even more rare than the last, of which it 
is presumably a preliminary stage. I may note as a sexual 
difference that the three parts of the breast-bone have a 
greater tendency to fuse in man than in woman. 
The time of closure of the cranial sutures (by which I 
refer to the three great sutures of the vault) is very uncer- 
tain. Perhaps this simple statement would suffice, were it 
not that rules have been given to determine the a<je of the 
skull from the condition of the sutures. In 1890 I pub- 
lished my observations on 100 skulls. The process of co- 
ossification begins on the inside of the skull. It usually 
begins at about 30. The order and rate of closure are very 
varying. Complete closure may occur at any time. I have 
an instance of it in this thick calvaria of an epileptic black 
boy of 15. It does not necessarily depend on the thickness 
of the skull, for one of a girl of 20 in which they are all 
open is nearly as thick. Here is the calvaria of a woman 
of 52 on the outside of which the sutures appear open, 
though they are mostly closed within. The sutures may VAKIATION IN THE HUMAN SKELETON. 
19 
be distinct or open in old age, but I consider an abnormally 
early closure much more frequent. Partially closed sutures 
alone do not indicate an age much above 30. Sutures 
absolutely open in most cases mean an earlier age. 
My observations on the hyoid embrace among whites 
only 44 men and 20 women. The lesser horn is often 
rudimentary or wanting. It may be connected by either 
a joint or a ligament. Its union to the body by bone 
is uncommon, and when it occurs is a sign of advanced age. 
I have seen both lesser horns fused with the body only once 
before fifty, in a man of 31. Our chief guide is, therefore, 
the great horns. I have seen them both joined only six 
times out of 31 subjects under 45 (all but two of which 
had passed 20). After 45 years both are joined in more 
than half the cases. They may, however, be free in extreme 
age. 
The general changes in the bones in later life are vague 
and ill-defined. The atrophy, which is often seen in the 
bones of the very aged, begins at no definite period. I 
have in my collection bones of persons over 70 which can- 
not even on section be distinguished from those of early 
maturity. In extreme age atrophy is, of course, to be ex- 
pected. 
The skull shows a marked atrophy of the face with an 
enlarging of the angle of the jaw, especially when edentu- 
lous. The cranium itself does not show the same wasting 
as the face, but on the contrary may be thickened. The 
idea that the angle of the neck of the femur is diminished is 
no longer held. The ossification of cartilage, the closure 
of sutures, increased roughness along lines of insertion of 
tendons, are often changes due rather to constitutional causes 
than to age. Their significance must be carefully weighed. 
c O y o 
AVliile I have felt justified in speaking with greater confi- 
dence on the determination of the sex than I did sixteen 
years ago, in the question of age it is just the reverse. 20 
TIIE RANGE AND SIGNIFICANCE OF 
Asymmetry. 
The question of asymmetry of the limbs requires brief 
mention. I have measurements of the separate bones of 
about 75 subjects, of which rather more than two thirds 
were male. As to the arm, the humerus is almost 
always the longer, and the right radius usually; the com- 
bined length is almost always greater on the right. I find 
the average difference 6 mm. Rollet, who measured the 
bones of 50 male and 50 female subjects, puts it at from 7 
to 8 mm. 
As for the legs, the femurs differ about 2 mm., one side 
predominating about as often as the other, the tibiae by 
some 3 mm., the left side being more often the longer. The 
combined length is greater on the left in distinctly more 
than half the cases, the average excess being from 4 to 5 mm. 
liollet makes the differences somewhat greater and apparent- 
ly finds that neither side is particularly favored. The two 
longer bones of a limb are usually on the same side, but 
not always. Wright’s measurements on legs on the living 
and Garson’s on skeletons, each gives the predominance to 
the left limb. My observations show an equality between 
the sides of the body that is greater than I had anticipated. 
I may mention that incidentally to this investigation I 
have been able to carry some light where it is much needed, 
namely, as to the value of measurements on the living, but 
this is foreign to the present discussion. How far inequal- 
ity of the central nervous system may be correlated with 
that of the limbs is one of those questions on which sur- 
mises far exceed exact knowledge. I have here the base 
of a female skull showing almost extraordinary asymmetry 
in favor of the left side, yet the bones of the right arm ex- 
ceed those of the left by 1 cm., which though uncommon 
is hardly remarkable, and the bones of both legs are pecise- 
ly equal. VARIATION IN THE HUMAN SKELETON. 
21 
Tiie Estimation of the Height. 
If it he asked how far individual variations may affect 
our success in estimating the height, the answer must de- 
pend on the method that is employed. If we follow the 
best, or anatomical method, namely, that of putting the 
bones into proper position, making due allowance for soft 
parts and measuring the height, the individual variation 
does not count, because the problem is distinctly under 
the eye. But if parts are wanting so that we must turn to 
the method of calculating by proportions, individual varia- 
tions are of the greatest importance. Indeed, they are so 
important that they make absolute certainty almost impos- 
sible. Should the legs be wanting we must turn to elab- 
orate tables which I have calculated to enable us by multi- 
plying the length of the spine from atlas to sacrum by cer- 
tain coefficients for each sex, to obtain the height; some- 
times with wonderful exactness. Still, not only does the 
length vary considerably, but the number of anomalous 
spines observed is increasing. Those with six lumbar ver- 
tebra; are common enough. My tables show that usually 
this increases the proportionate length of the spine, but 
not invariably. Thirteen and eleven thoracic vertebra; 
without corresponding decrease or increase in other regions 
are occasionally met with. Then we have the proportions 
reckoned from the height of the pubes, and finally from the 
separate bones. From large numbers of subjects measured 
in our anthropological laboratory, both before or after dis- 
section, I selected forty, twenty male and twenty female, 
in each of which the humeri, radii, femora, and tibiae of 
both sides had been measured. From these I calculated 
the height according to my own tables from the spine ; ac- 
cording to the methods of Topinard, Kollet and Manouvrier 
from the humerus, radius, femur and tibia. The height may 
be reckoned from any one of these bones, but I have pur- 22 
THE RANGE AND SIGNIFICANCE OF 
sued the method of taking the average length of the bones 
of both sides, and having found the height from each of 
humerus, radius, femur and tibia, to take the average of 
the four as probably the nearest approach to the true height. 
I have repeated this process according to the method of 
each of these three observers. 
Not to stop for details, it appears that by almost any of 
these methods we can come within 2.5 cm. or 1 inch in 
about half the cases, within 5 cm. or 2 inches in about 
three fourths of them, which leaves one fourth remaining 
in which the error is serious.1 
The Skeleton and the Figure. 
What relation, if any, there may be between the shape 
of the bones and that of the body, is a very interesting 
question, which under certain circumstances may well be- 
come a momentous one. Can we from our knowledge of a 
person’s figure predicate at least the general character of 
his bones, and conversely if bones are laid before us can 
we say anything worth saying as to the soft parts that once 
clothed them? Surely, putting aside extraordinarily tall or 
short or peculiar figures, the part we should expect to show 
the greatest individuality is the skull. 
A typical long and a typical broad skull are of course 
readily distinguished. There are also typical long and 
narrow and typical short and broad faces, such as we can 
imagine belonging to the melancholy Trois Esehelles and 
the rollicking Petit Andre, the two hangmen in Quentin 
Durward. In the first the nasal opening is narrow and 
pointed,, in the other broad and almost quadrilateral; in the 
former the jaw is narrow, the roof of the mouth highly 
vaulted, and the angle of the lower jaw more obtuse than 
1 This subject is discussed at length in a paper read before the Associa- 
tion of American Anatomists at Washington, May 30, 1894, which is to 
appear in the Medual Hecord. VARIATION IN THE HUMAN SKELETON. 
23 
in the other. But such typical faces are not very common. 
The characteristic points are usually wanting in clearness. 
iSot rarely they are even transposed, so that for instance a 
short face may have the lower jaw with the angle of a 
broad one, and vice versa.1 
Often when overcome by the intense weariness of a Fac- 
ulty meeting, I have sought relief in asking myself which 
of my colleagues I should be able to recognize were their 
nicely macerated skulls set on the table before me. There 
are striking types of heads in that august assembly, but I 
am convinced that the skulls I could swear to would be 
very few. Even so characteristic a countenance as that of 
the sad-eyed Mongolian is not, when reduced to a skull, so 
strikingly evident that one will readily pick it out from a 
number. Most of the characteristics of a head and face, 
the size being excepted, are in the soft parts. 
The problem may present itself in various ways. Sup- 
posing that we had the skulls of two known persons before 
us, the identification should in most cases present no in- 
superable difficulty. In many cases we could declare with 
absolute confidence that a certain skull could not have be- 
longed to a certain person. But while I do not question 
that the careful and minute study of an expert can accom- 
plish much, I am anxious to insist that the identification of 
a skull from our remembrance of a dead person, even with 
the assistance of photographs, is in most cases no easy task. 
As for the rest of the body, it cannot be denied that our 
results are more negative than positive. The shoulder- 
blade is a very variable bone. I do not know what range 
of variation a great series of the scapula} of the larger felidte 
might present, but a small one shows nothing like that of 
the human race, I might add even that of the Caucasian. 
Yet I am quite unable to find any connection between its 
1 Formen des Ober und Unterkiefers bei den Europseern. Dr. J. Koll- 
raann. Schweizerischen Vierteljahrsschrift fur Zahnheilkunde, 1892. 24 
THE RANGE AND SIGNIFICANCE OF 
shape and the contour of the shoulders. The length, 
breadth, inclination and shape of the acromion are all val- 
ueless. Perhaps the only deduction that seems clear is that 
the leverage required by a long arm calls for a long scapula. 
Conversely, however, I may say, that heavy shoulders 
indicate large humeri. In the strongest arm bones the 
spiral formation is particularly developed. I have often 
seen in this type a large, prominent, external supracondy- 
loid ridge suggesting that of the gorilla. I have never 
seen this ridge strongly developed on a weak or on a female 
humerus. 
The variations in the details of the femur are endless. 
I have been bathed in trying to find any definite connection 
between the figure and the various features of the thigh 
bone, such as length, or angle of neck, its forward inclina- 
tion, and indeed the general characteristics of the shaft. I 
have been inclined to associate the length and forward in- 
clination of the neck with a well marked lumbar curve, but 
have no evidence that can be called convincing. Two pecu- 
liar shapes of the thigh bone have of late received particular 
attention, one of which, called the pilastered femur, char- 
acterized by the prominent posterior ridge and usually 
strongly bent, is associated with a very narrow tibia. 
While I have often found this association, it is not invari- 
able, neither does it always imply large muscular develop- 
ment. The other is the flattened femur, which, except for 
its greater length, suggests that of the gorilla. I have 
found it generally in very powerfully built men. I have 
frequently seen the bending back of the head of the tibia 
which, together with a facet at its lower anterior border, has 
in prehistoric skeletons been advanced as evidence that an 
upright position was not fully attained. The studies, how- 
ever, of Mr. Arthur Thomson, of Dr. R. Havelock Charles 
and of Monsieur Manouvrier have shown that it is rather 
to be considered as associated with powers of excessive VARIATION IN THE HUMAN SKELETON. 
25 
flexion, and perhaps with the habit of* walking with bent 
knees. These peculiarities are seen in the leg bones of 
Orientals who sit squatted on the ground. Here is a 
Chinese tibia which had the lower articular surface con- 
tinued on to the front. It in no way implies in either ease 
that the upright position cannot he assumed. I have fre- 
quently seen a lengthening of the articular surfaces of the 
head of the femur which is associated with these features, 
but 1 have found it independent of any of them. As to 
the thin tibia of prehistoric skeletons, we often find striking 
examples of it in the dissecting room. 
To come to practical application, I do not believe that 
it is possible to predicate the shape of the bones from that 
of the body, nor vice versa, with any great certainty. Of 
ten we should fall into grievous error in attempting it. I 
have notes on two male subjects that were in the dissecting 
room at the same time, which I shall call A and B. A’s 
height was 17(5.(J cm. (say 5 ft. 9£ in.). B was a mere 
trifle (() mm.) taller, but with broader shoulders, broader 
hips and longer legs. My notes state that A was slender, 
thin, with a flat chest, rather long neck, thighs somewhat 
bent outward. B was of very powerful build, with square, 
thick shoulders, very deep chest, strong legs. B’s shoul- 
der-blade is the larger, but by no means strikingly so. 
Had I measured the arm bones I have little doubt that one 
factor of B’s heavier shoulders would have been apparent. 
But the femurs were a surprise to me. Each is remarkably 
heavily made, and though of different types one would 
hesitate which to ascribe to the more powerful man. 
In A it approaches the pilastered form, in B it is broad 
and flat. Here again are some very interesting bones from 
a lightly made, almost puny blind boy of nineteen, who had 
spent nearly his whole life in an almshouse in a sedentary 
manner, yet they arc distinctly strong bones. The humerus 
in particular presents a striking contrast to that of the 
female mill operative who seemed almost twice his size. 26 
TIIE RANGE AND SIGNIFICANCE OF 
This carries us to the causation of* peculiarities of structure. 
Manouvrier argues at great length that the very thin tibia 
comes from the great development of the tibialis posticus, 
and the pilastered femur from that of the cruneus, useful 
muscles for walking in a hard country and with bent knees. 
While I would be the last to question the tendency of the 
human body in common with’ all other organisms to adapt 
itself to its surroundings, I cannot regard such explana- 
tions as sufficient. Manouvrier mantains also that the 
third trochanter is associated with the action of the gluteus 
maximus. I have endeavored to show on a previous oc- 
casion that the theory which explains the shape of bone by 
mechanical strain is unsatisfactory. We find the third tro- 
chanter only in a certain proportion among savage races in 
which presumably every one lived pretty much the same 
life. We find remarkable instances of it in delicate bones 
which show no signs of great muscular development. Fi- 
nally we find it in bones that are too young to admit of its 
having been pulled into prominence by the muscles of its 
possessor. Manouvrier argues that the platycnemic tibia is 
due to the mode of life of the individual from the fact that it 
is not found in childhood. This does not follow. At early 
adolescence many changes take place in the framework of 
the body, then beginning to assume its final shape, which 
can be accounted for by no mechanical cause. Such are 
the development of the nose and of the larynx at the time 
when, to quote Thackeray, the boy’s voice ranges from an 
unearthly treble to a preternatural base. Moreover, we are 
not now concerned with the question how great races ac- 
quired their charateristics, but whether mechanical expla- 
nations will account for the individual peculiarities found 
among us. Here we see every variety of shape of femur 
and tibia, to say nothing of shoulder blades. Here are pre- 
The Origin of Individual Peculiarities. VARIATION IN TIIE HUMAN SKELETON. 
27 
historic forms occurring in the midst of us. Here are the 
strongly developed bones of the blind boy who did nothing. 
I have spoken of the wonderful variability of the human 
scapula. There is every reason to believe that it acquires 
its permanent peculiarities at a very early period. Macalis- 
ter has found characteristic differences in the acromion at 
from two to four years, and I have two tracings of the out- 
line of peculiar shoulder blades made for me by Dr. Monks 
from two sisters, aged seven and ten. The resemblance of 
these two tracings and the early development of outline is 
strong evidence that this depends upon other than mechan- 
ical causes. Without questioning that external influences 
can and do modify the shape, I am convinced that the 
main characteristics of each body are largely hereditary and 
are predetermined from the very beginning of develop- 
ment. 
The Significance of Anomalies. 
I have met with most of the recognized anomalies of the 
skeleton, and with some of great rarity. Large third 
trochanters, supra-condyloid processes, supra-troclear per- 
forations, I have seen galore. Here is a large para-mas- 
toid process of the occipital bone, which is found in many 
mammals, especially in the herbivora and rodents ; here is 
a sternum with the manubrium reaching to the third rib, 
as is found in gibbons ; here is the fossa praenasalis, best 
developed in the seal tribe. 
Our collection of anomalous spines shows many curious 
forms. It is claimed that man is about to lose one of his 
24 prae-sacral vertebras. I have specimens showing the 
sacrum encroaching on the lumbar region, transforming the 
vertebra above it into a transitional one and reducing to 
sixteen the thoracic and lumbar vertebras, it may be at 
the expense of one region or of the other. I have 
instances of the reduction of the thoracic vertebras to 28 
THE RANGE AND SIGNIFICANCE OF 
eleven without any remarkable disturbance in any region. 
There are, on the other hand, cases of increase of the pra?- 
sacral vertebra?. There may be twelve thoracic and six 
lumbars or thirteen thoracic and five lumbars. Here are 
cervical ribs of various degrees of development. This is a 
bicipital rib recalling the condition in some whale-bone 
whales. Here finally on a spine showing cervical ribs and 
the suppression of a thoracic vertebra, is an absolutely 
unique case of absence of the anterior arch of the atlas. 
Much do we hear of atavism. Every anomaly is forced 
to represent something animal, a short spine is that of the 
orang, a long one that of the gibbon, one anomaly recalls 
the sloth, another the seal, another a ruminant, another a 
marsupial. In the muscular system we have been carried 
back both to birds and to snakes. 
We cannot have inherited the fossa-pra?nasalis from the 
seal. If it be inherited at all it must be from some com- 
mon ancestor. Following this line of reasoning, we find 
that if all animal resemblances are reversions, the primitive 
ancestor must have been a very curiosity shop of peculiarities, 
in direct defiance of that principle of evolution which brings 
from the simple the more complex. Convinced as I am 
that every bodily difference between man and non-rational 
animals is of degree and not of kind, I am astonished and 
perplexed by the great net-work of analogies extending 
throughout nature. No one can ignore them without wil- 
fully shutting his eyes. But the very multiplicity of these 
resemblances assures me that some other law than that 
of heredity must be invoked to account for them. They 
cannot be represented by a tree-like figure. They spread 
out every way. The opinion is growing daily stronger, 
among serious scholars, that if man’s body came from a 
lower form it was not by a long process of minute modifi- 
cations, but by some sudden, or comparatively sudden, 
transition. The fabulous missing-link, once so accurately VARIATION IN TIIE HUMAN SKELETON. 
29 
described by Haeckel, is retreating to the limbo of worn out 
hypotheses. 
The Vital Principle. 
The phenomena of growth show unmistakable evidence 
of an immanent force presiding over the development of 
the living organism, essentially different from the forces 
of non-living matter. Its action is strikingly shown in 
anomalies ; not, indeed, in their production, but in remedy- 
ing the evil. If, for instance, there be but eleven thoracic 
vertebne in a spine, it is impossible to say which one is 
wanting, for a slight modification is found to have taken 
place in several by which the symmetrical development 
of the spine is maintained. In the unique case of total 
absence of the anterior arch of the atlas, a strong 
ligament running from the odontoid to each lateral 
mass holds the bone securely and yet allows movement. 
By what purely mechanical process can this wonderful 
adaption have been brought about? One of the charac- 
teristics of living matter is that its growth is directed to 
the perfection of the organism as one whole, not as a col- 
lection of independent particles. This is the action of the 
vital principle, which science can no longer afford to ignore.