i8o 



Human Physiology. 



There must be a centre of consciousness, of the sense of 

 personal identity, of will of the unity of life which feels and 

 governs our whole being. 



It must be observed that the most intimate relations every- 

 where exist between the two great nervous systems the 

 cerebro-spinal and sympathetic, or the nerves of animal and 

 vegetative life. The latter are first in order, 

 and build up the former. First, vegetative 

 nerve matter; then blood and its circulation 

 in vessels formed by these primitive nerves; 

 then the formation of the nerves, spinal 

 chord, and brain of the animal system. 

 Fibres of spinal nerves mingle with the 

 ganglia of the sympathetic; fibres are inter- 

 woven, and act upon each other. In this 

 way the emotions of the mind influence the 

 action of the heart, the digestion, the action 

 of the liver, the secretion of saliva, milk, &c., 

 as we shall see further in considering the functions of nutrition, 

 circulation, secretion, and excretio.rv, 



GANGLION OF A 



SYMPATHETIC 



NERVE. 



