100 GENERAL PHYSIOLOGY. 



demands that their own organs should likewise be duly nourished. 

 Moreover, these organs themselves contain both motor and sensory parts, 

 i. e., muscular and nervous tissues. The former are exemplified in the 

 muscles of mastication and deglutition, the muscular coats of the ali- 

 mentary canal, the walls of the heart, the muscular tunic of the arte- 

 ries and of the ducts of glands, the respiratory muscles, and the mus- 

 cular fibres of the larynx and air-tubes. The latter consist of various 

 nerves and nervous centres, especially of the so-called tymp&thetio 

 nervous cords and ganglia, hence named the organic, nervous system. 

 But even the animal nervous system, in its various healthy and mor- 

 bid states, has most important influences upon all the nutritive vege- 

 tative functions, aiding or interfering with those of digestion, nutrition, 

 secretion, and the rest. 



The nutritive vegetative functions begin, with the exception of 

 digestion, to be manifested at the very commencement of individual 

 life, and they continue through the whole period of existence, from 

 youth, through the adult state, to old age. But the life of the indi- 

 vidual is limited, and to avoid the extinction of race, which would 

 otherwise follow such limitation, provision is made for the continuance 

 of the species. Hence in both plants and animals, an additional 

 vegetative function is met with, by means of which, through the evo- 

 lution and development of germs, gemmules, or ova, new individuals 

 are successively formed from previously existing parents, generation 

 after generation. This, the last function we have to mention, is the 

 reproductive vegetative function, in which are included the phenomena 

 of development and growth. 



The following table will serve not only to give a general view of the 

 different functions, but also to indicate the order in which they are 

 hereafter described. 



The Functions of Living Animals. 



( Motion. 



ANIMAL FUNCTIONS \ Sensation, regulation of movement, and the higher 

 ( psychical functions. 



VEGETATIVE FUNCTIONS : 



Digestion : 



Mastication, 



Insalivation, 



Deglutition, 



Digestion proper, or Chymincation. 

 Absorption ; Chylitication. 

 Nutritive, . . -j Circulation. 



Nutrition and Separation. 

 Sanguification. 

 Secretion. 

 Excretion. 



Respiration ; Production of Heat, Motion, and Elec- 

 tricity. 



Reproductive, . j Development and Growth. 





