V1 THE STRUCTURE OF MAN 
ever, needed. Our accepted views as to the inter-relationships 
between the greater groups of animals are largely based upon the 
assumption that similarity of gross structure implies community of 
origin. It is now becoming evident that an essentially similar 
definitive condition may be independently reached, under advanc- 
ing modification along parallel lines, by members of independent 
groups of animals; and there is reason to suspect that some 
of our classificatory systems are unnatural and erroneous from 
want of appreciation of this principle of “convergence.” We must, 
therefore, not lose sight of the possibility that some of the 
characters which modern Man and the higher Apes have in common 
may have been independently acquired. A notable instance is fur- 
nished by the ridges which connect the tubercles of the upper 
molar teeth, described by Huxley and Topinard. On comparing 
the little worn upper molars of, say, a female Chimpanzee and 
Man, one might at first sight be disposed to conclude that modern 
Man has descended from ancestors hardly differing from the 
modern Apes. On comparing the entire Man-Ape series, how- 
ever, it is found that these ridges, and more especially that of 
Topinard, are extremely variable and not infrequently absent in 
individuals of both Men and Apes, and it becomes therefore 
evident that such a conclusion, if not unwarranted, is premature. 
If for no other reason than this, it will be obvious that consider- 
able interest attaches to the more precise determination, in the 
future, of the limits of detailed structural variation in Man 
and the Anthropoid Apes. With regard to variation in Man 
some very useful results have been obtained, during the last five 
years, under the auspices of a “Collective Investigation Com- 
mittee” of the Anatomical Society of Great Britain and Ireland, 
of which I have the honour to be a member. Subjects chosen 
for investigation year by year are taken in hand in the leading 
dissecting rooms throughout the kingdom. The work of the 
student, becoming thus a research work, is ennobled; and the 
reports embody a mine of accurate information which, edited 
and tabulated, is of great service to both the surgeon and scientific 
anatomist. | : 
Our views on some of the topics dealt with in this volume 
may become very much modified as work of the above-mentioned 
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