378 FUNCTIONS OF THE NERVOUS SYSTEM, [ch. i. 



Nuck plainly subscribes to this doctrine in his ' Epistola Ana- 

 tomica de novis inventis/ but, however, in the present day we 

 are certain, that the pineal gland is really a part of the cortical 

 substance of the brain, connected by two medullary peduncles 

 with the thalami nervorum opticorum, and, consequently, not a 

 lymphatic gland. 



The ganglia of the nerves were known to Galen, Fallopius, 

 Eustachius, and Willis, but their function was first taught by 

 Vieussens ; who considered them to be receptacles of the animal 

 spirit, in which it could be nourished, preserved, and rectified, 

 by the arterial blood flowing through them ; others, however, 

 amongst whom was Winslow, looked upon them as little brains, 

 from which fresh animal spirits are secreted, and new nerves 

 given ofi^. Lancisi assigned to them a muscular coat, by which 

 the animal spirits contained in them might be impelled for- 

 wards; Tarin considered them to be accidental callosities; 

 Meckel and Zinn were of opinion that they divided the larger 

 nerves into smaller, and gave them another direction. Johnstone 

 maintained that ganglia were peculiar to those nerves not sub- 

 ject to volition. Various objections were raised against this 

 doctrine, especially by the illustrious Haller, and Haase, but 

 Tissot and Pfeffinger approved of it. There will be an oppor- 

 tunity of discussing this again; and since Tissot has fully 

 treated of the matter in his work on the nerves, I will not 

 abuse the patience of the indulgent reader by the repetition of 

 things well known. 



SECTION VII. THOSE WHO HAVE DENIED THE EXISTENCE OF 



ANIMAL SPIRITS. 



The existence of the animal spirits being received, from the 

 most remote period, descending by tradition, as it were, no one 

 proved or attempted to prove it as it ought to be. Celebrated 

 men began, however, to call in question the existence of these 

 animal spirits, especially since the doctrine seemed to be a gra- 

 tuitous assumption ; amongst whom were Argenter, Alexander 

 Benedictus, Quercetanus, Nymman, Fernel, Avicenna, Felix 

 Plater, Helmont, Cabroli, Back, Bidloo, Lister, Brini, Parisinus, 

 and many others : of these some attempted to substitute for the 

 discarded hypothesis one not more demonstrable, namely, that 



