720 



NERVOUS SYSTEM. 



"We have thus discussed only those views with regard to the functions of the cerebel- 

 lum which are supported by experimental or pathological facts, and have not touched 

 upon the vague and unsupported ideas advanced by various writers before the publica- 

 tion of the remarkable observations of Flourens. There is no proof that the cerebellum 

 is the organ presiding over memory, the involuntary movements, general sensibility, or 

 the general voluntary movements. The only view that has any positive experimental or 

 pathological basis is that it presides over equilibration and the coordination of certain 

 muscular movements, and is, perhaps, in some way connected with the generative 

 function. 



Ganglia at the Base of the Encephalon. 



At the base of the encephalon, are found several collections of gray matter, or gan- 

 glia, some of which have functions distinct from those already described in connection with 

 the cerebrum and cerebellum; but most of them are so difficult of access in living ani- 

 mals, that we possess very little definite information, even with regard to their general 

 properties. We have, however, a tolerably complete knowledge of the functions of the 

 medulla oblongata and the tubercula quadrigemina, and have some idea of the physiology 

 of the tuber annulare ; but the functions of the corpora striata, optic thalami, ventricles, 

 pineal gland, peduncles, etc., are little understood, and the speculations of the older 

 writers, with the indefinite experiments of modern physiologists, upon these parts, will 

 be passed over very briefly. 



Corpora Striata. 



These bodies are somewhat pear-shaped, and are situated at the base of the brain, 

 partly without the cerebral hemispheres and partly embedded in their white substance. 



FIG. 228. Corpora striata. (Sappey.) 



1, fifth ventricle ; 2, the two laminae of the septum lucidum meeting in front of the fifth ventricle ; 8, hippocampus 

 minor ; 4, posterior portion of the corpus callosum ; 5, middle portion of the fornix ; 6, posterior pillar of the 

 fornix; 7, hippocampus major; 8, eminentia collateralis ; 9, lateral portions of the fornix: 10, choroid plexus: 

 11, taenia semicircularis ; 12, corpus atriatum. 



