608 ADAPTATION OF ANIMALS. 



the earth to escape his foes. The tortoise is compelled to ac- 

 commodate itself to the shell, which is hard and inflexible, 

 and in no way obedient to the will of its bearer ; yet that 

 very shell, although so apparently inconvenient, serves as its 

 protection. The turtle is protected in the same way; but its 

 delicious flesh brings numerous enemies to attack it, from 

 whom it has a hard task to escape. The egg of the tortoise, 

 it may be remarked, has a very haid shell ; while that of the 

 turtle is quite soft. 



