CH. v.] SYSTEM OF THE FORCES OF ANIMAL LIFE. 353 



diffused brain (677, iv). If, however, the nerve-medulla in the 

 head secretes and transmits the vital spirits only, then life 

 ceases with the removal of the head, except in so far as vital 

 spirits already secreted and transmitted may still remain in 

 the nerves (661, 677, ii); until these are exhausted, various 

 processes may go on in the body in their natural co-ordination, 

 although no sentient actions can take place in sentient animals. 

 The functions of the brain may be compared with a fountain 

 supplied from a brook, which waters flowers and plants : the 

 latter are the nerves ; the fountain represents the animal-sen- 

 tient force, and the brook the primary vital force. The fountain 

 may be removed, and still the flowers may flourish, provided 

 the sources of the brook be not cut off", but the flowers and 

 plants live only so long as the supply of water already in the 

 garden holds out. 



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