96 



THE GENESIS OF SPECIES. 



[CHAP. 



allied to the sloth, namely, the great ant-eater (Myrme- 

 cophaga), we have again an ornithic character in its horny 

 gizzard-like stomach. In man and the highest apes the 

 caecum has a vermiform appendix, as it has also in the 

 wombat ! 



Upper Figure ANTECHTNUS MINTJTISSIMTTS (implacentaT). 

 Lower Figure Mus DELICATUXUS (plae&ntaf). 



Also the similar forms presented by the crowns of the 

 teeth in some seals, in certain sharks, and in some extinct 

 Cetacea, may be referred to ; as also the similarity of the 

 beak in birds, some reptiles, in the tadpole, and cuttle- 

 fishes. As to entire external form, may be adduced the 

 wonderful similarity between a true mouse (Mus delicatu- 

 lus) and a small marsupial, pointed out by Mr. Andrew 



