ANATOMICAL STRUCTURE OF ANTHROPOID APES. 187 



incisors are the smallest. The long and strong 

 upper canine teeth, which are laterally compressed, 

 display a sharp posterior angle, and an anterior and 

 inner longitudinal furrow. 



It has sometimes been said that the grooves 

 found on the external contour of the back teeth of 

 anthropoids, extending to their roots, constitute a 

 not unimportant distinction between their structure 

 and that of the human teeth, in which the grooves 

 do not extend to the roots. But the corresponding 

 human teeth do sometimes exhibit very deep and 

 extensive furrows. I cannot, therefore, ascribe any 

 peculiar significance to this assumed distinction. 

 The development of the canine teeth, like those 

 of beasts of prey, seems to me much more important. 

 A supernumerary back tooth may sometimes be 

 observed both in man and in anthropoids, including 

 also the gibbon.* 



The stomach and intestines of these animals pre- 

 sent only a few striking differences from the same 

 organs in man. The length of the intestines varies 

 in man as well as in anthropoids. I have only 

 observed the valvulx conniventes to be somewhat 

 clearly developed in the gorilla and the orang. The 

 caecum of these apes is long, broad, placed with the 

 power of free movement in the peritoneum, and 

 furnished, especially in the case of the orang, with 

 a large, very long, and spirally coiled vermiform 

 appendix. 



The liver is divided into two principal lobes, but 



* As, for example, in Hylobaies syndactylus. Comp. Giebel, 

 Odontographia, p. 2 : Leipzig, 1855. 



