CHAR A CTERISTICS. 



parallel to those of the other toes. In this respect, as the figure shows, the foot of 



man is markedly ditierent from that of the gorilla and the other apes. With the 



■curious exception of the orang, in which the great toe is often entirely devoid of 



any trace of such appendage, all the fingei-s are furnished with nails. In the liigher 



forms these nails are of a flattened .shape in all the digits: and this flatness is 



always characteristic of the nail of the great 



toe, although the other digits of the lower 



forms have curved nails. In order to form an 



efficient support for those nails, the hones of 



the terminal joints of the digits, with the 



exception of the index finger of the lemurs, 



are transversely flattened out : and are thus 



veiy different from tliose of the Rodents and 



Carnivores. That the hand and foot should 



have perfect freedom of motion, it is of coui-se 



necessar}^ that the bones of the fore-arm and 



lower leg should remain completely separate 



from one another: and, as we see from the 



figured skeletons, the radius and ulna in the 



fore-ann, and the tibia and fibula in the leg, 



are both equally well developed and capable of 



motion upon one another. Another important 



point as regards the free use of the arms is 



the presence of complete collar-bones, wliieli 



are always well developed in apes and 



monkej's, as they are in ourselves. 



If we look once more at the figures of the 

 skeletons of man and the gorilla we shall not 

 fail to observe that in tlie .skull the .sockets, 

 or orbits, of the eyes are completely sur- 

 rounded by a ring of bone, and that tlie 

 sockets themselves look almost directlj- for- 

 wards. This complete bony ring round the 

 eye-sockets at once serves to cUstinguish the 

 skulls of all the Primates from those of most 

 of the Carnivores. 



In correlation Avith the herbivorous habits 

 of the majority of the species, the teeth of the 

 Primates are adapted for giinding ; the cheek- 

 teeth having broad flattened crowns, wliich 

 may either, as in ourselves, be surmounted by tubercles, or by transverse ridges. 

 Except in one family of American monkeys, there are always three molar teeth in 

 each side of either jaw, the last of which corresponds with our own " wisdom- 

 tooth " : and these molar teeth are invariably larger and more complicated than 

 the premolars. Very generally, as in ourselves, the number of the latter teeth is 

 reduced to two on each side, and no living member of the order has more than 



VOL. I. 2 



SKELETON OF THE GORILLA ; 



and male (c?) and (j) female skulls. 



