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dentition of these anthropoid apes, the number and kinds of the teeth, 

 like those of all the quadrumana of the old world, correspond with 

 those in the human subject; but all these apes differ in the larger 

 proportionate size of the canine teeth, which necessitates a certain 

 break in the series, in order that the prolonged points of the canine 

 teeth may pass into their place when the mouth is completely 

 closed. In addition to the larger proportionate size of the incisors 

 and canines, the bicuspids in both jaws are implanted by three 

 distinct fangs two external and one internal: in the human 

 species, the bicuspids are implanted by one external and one 

 internal fang : in the highest races of man these two fangs are 

 often connate ; very rarely is the external fang divided, as it con- 

 stantly is in all the species of the orang and the chimpanzee. 



With regard to the catarrhine, or old-world quadrumana, the 

 number of milk teeth is twenty, as in the human subject. But 

 both chimpanzees and orangs differ from man in the order of de- 

 velopment of the permanent series of teeth : the second true molar 

 comes into place before either of the bicuspids have cut the gum, 

 and the last molar is acquired before the permanent canine. We 

 may well suppose that the larger grinders are earlier required by 

 the frugivorous apes than by the omnivorous human race; and 

 one condition of the earlier development of the canines and 

 bicuspids in man, may be their smaller relative size as compared 

 with the apes. The great difference is the predominant develop- 

 ment of the permanent canine teeth, at least in the males of the 

 orangs and chimpanzees; for this is a sexual distinction, the canines 

 in the females never presenting the same large proportion. In man, 

 the dental system, although the formula is the same as in the 

 apes, is peculiar for the equal length of the teeth, arranged in 

 an uninterrupted series, and shews no sexual distinctions. The 

 characteristics of man are exhibited in a still more important 

 degree in the parts of the skeleton. His whole framework pro- 

 claims his destiny to carry himself erect ; the anterior extremities 

 are liberated from any service in the mere act of locomotion. 



With regard to the foot, I have shewn in my work On the 

 Nature of Limbs, that in tracing the manifold and progressive 

 changes of the feet in the mammalian series, in those forms where 

 it is normally composed of five digits, the middle is usually the 

 largest; and this is the most constant one. The modifications in 

 the hind foot, in reference to the number of digits, are, first, the 

 reduction and then the removal, of the innermost one; then the 



