vi THE STRUCTURE OF MAX j 



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 



