508 



ELEMENTARY PHYSIOLOGY 



ventricles. The inner sides of the optic thalami are 

 connected by a small coniinissure (Fig. 163, C), which 

 extends across the third ventricle ; their outer sides are 

 imbedded in the substance of the cerebral hemispheres 

 with which they are connected by nerve fibres, and from 



Pio. 163.— Diagram of a Hokizontal Section of the Brain above thk 

 Floor of the Lateral Ventricles. (After Hirschfeld and Leveill^.) 



Sp.c. spinal cord ; B, bulb ; Cb, Cb, cerebellum ; 4, fourth ventricle ; 

 Q.P., Q.A, corpora quadrigemina ; P, pineal gland; 3, third ventricle; 

 5, fifth ventricle ; cc, front part of corpus callosum ; iK, IV, H\ lateral 

 ventricle ; OT., optic thalami ; CS, CS, corpus striatum ; C, com- 

 missure of optic thalami. On the left side CS marks the corpus 

 striatum, into which an incision has been made and a flap, /., turned 

 back to show its internal striated appearance. 



their hinder end a bundle of fibres sweeps forward to 

 pass into the tract of the optic nerves. 



The Corpora Striata. — Each corpus striatum may be 

 regarded as a mass of grey matter deposited obliquely, as 

 was each optic thalamus, on the course of the crura 



