24 PHYSIOLOGY AND MORPHOLOGY OF ANIMALS. 



or, more briefly, animal functions and organic functions. 

 The animal functions are those which are distinctive of 

 animals. The organic functions are those which are 

 possessed in common by animals and plants, and are 

 therefore coextensive with life. Thus an animal may 

 be regarded as a plant with certain higher and distinc- 

 tive functions superadded. So also man may be re- 

 garded as an animal with certain higher and distinctive 

 functions or faculties superadded. As the idea of ani- 

 mal life is realized in proportion as the distinctive ani- 

 mal functions predominate over the organic, so also 

 the idea of human life is realized only in proportion as 

 the distinctive human faculties predominate and control 

 the animal. 



Now these superadded distinctive animal functions 

 are all concerned with conscious action and reaction be- 

 tween the external world and the organism. They are 

 therefore divisible into sensation and consciousness 

 (action) on the one hand, and will and voluntary mo- 

 tion (reaction) on the other. These are, however, very 

 closely related, being both connected with the nervous 

 system. The organic functions — viz., those common to 

 all life — are subdivided into two more widely separated 

 groups, viz., the nutritive and reproductive. The nutritive 

 functions are all that assemblage of functions which 

 co-operate for the conservation of the life of the indi- 

 vidual ; the reproductive, all that assemblage of functions 

 which co-operate for the conservation of the kind, even 

 though the individual must die. 



, . ■ , f Sensation and consciousness. 



I Animal. ... J 

 Functions ) I W\W and voluntary motion. 



(Organic... Nutritive functions. 



( Reproductive functions. 

 Order of Treatment. — Of these groups we shall take 

 up animal functions first, because in the higher animals 



