Human Physiology. 



creature's, is written in their constitutions; and their bodily 

 organisation is the accurate expression of their mental and 

 emotional character. 



Natural history is full of example.-- of the adaptation of animate 

 to their conditions, and curious fashioning of implements, arms, 

 and armour. In the hedgehog and porcupine, the cuticle forme 

 itself into long sharp spines; on the armadillo it becomes 

 .a coat of mail; on the manis, a South-American ant-eater (Fig. 

 9), the armour takes the more flexible form of scales, which 

 are erectile; so that when the animal is attacked he rolls himself 

 up, winds his tail around him, and presents on every side a 

 chevaux de frise of sharp spear points. 



Fig. 9. THE MANIS. 



Of wild animals, the beaver presents one of the most remark 

 able adaptations of form to instincts. In the skull of the beavei 

 (Fig. 10) may be seen the four ever-sharp and ever-growing 



Fig. io. SKULL OF BEAVER. 



