346 ELEMENTARY ZOOLOGY. 



The sense of smell is very highly developed in some mam- 

 mals; more so than in any other vertebrates probably. 

 The external ear, as well as the sensory part of the in- 

 ternal ear, reaches its highest form in the mammals. 



The mental life of animals depends on the structure 

 of the brain, the character of the senses, and the connec- 

 tions that exist between these and the muscular tracts 

 of the body. While we cannot get into the animal mind, 

 we can experiment upon animals and measure what takes 

 place inside by the responses that occur outwardly. We 

 must remember, however, that we are liable to make the 

 mistake of assuming that the animal mind has undergone 

 all the steps that the human mind would take in coming 

 to a certain line of action. While the action might be 

 much the same as in man, the mental processes are al- 

 most certainly much simpler and more direct. 



After making all allowance for this fact, however, it is 

 certain that many mammals have some power of remem- 

 bering experiences and of changing conduct in accord- 

 ance with these experiences. To this extent they may 

 be educated. They form habits and get the skill that 

 comes from habitual action. They can compare situations 

 and choose in accordance with experience. As the 

 result of these powers, they reach conclusions in the pres- 

 ence of several conflicting appeals; conclusions which on 

 the whole lend to their success in life. There are those 

 who think these actions are reflexes even in the higher 

 mammals, but it is clear that they are accompanied by 

 "states of mind" comparable to what we call anger, fear, 

 hatred, pleasure, and sympathy. 



Students differ as to the existence of reasoning among 

 animals. If we mean by reasoning the formation of 

 abstract ideas, such as would be expressed among us by a 



