CHAPTER II. 



ANIMAL SENSATION AND PERCEPTION. 



ALT, animals communicate with each other and with 

 the external world through their senses, and by 

 means of their perception, hoth internal and external, 

 they possess knowledge and apprehension of one 

 another. In the vast organic series of the animal 

 kingdom, some are better provided than others with 

 methods, instruments, and apparatus fit for effecting 

 such communication. The senses of relation are not 

 found in the same degree in all animals, nor when 

 such senses are the same in number are they endowed 

 with equal intensity, acutcness, and precision. But 

 the fundamental fact remains the same in all cases ; 

 they communicate with themselves and with the 

 external world through their senses. 



We must now inquire what value the external 

 object of perception, considered in itself, has for the 

 animal, what character it has and assumes with 

 respect to his inner sense in the act of perception 

 or apprehension. Man, and especially man in our 



