Evolution 



mammal type, and to consider briefly the relationships of the 

 various groups that have sprung from it. The group whose 

 evolution has been perhaps least progressive is that of the Eden- 



FIG. 114. Oeba Armadillo. 



Photo : P.erridge 



tates, including the sloths, armadillos, and American ant-eaters 

 (Fig. 114). Then, on the one hand, we have , the herbivorous 

 types, including the remarkable sea-cows (Fig. 115), the rodents 

 (Fig. 116), and the hoofed animals, leading up from such com- 



FIG. 115. Sea-cows. 



paratively primitive forms as the coneys (Fig. 117) to such 

 highly specialised types as the giraffe (Fig. 118). The other series 

 of groups are believed to be more nearly related to each other 

 than to the aforementioned, and the nearest approach to their 



