THE CORTEX OF THE FORE-BRAIN, ETC. 



77 



of this section. A few words now in explanation of this 

 figure. 



You will at once recognize the frontal, occipital, and tem- 

 poral lobes. The latter is placed over the island of Rcil and in 

 part covers it. As in Fig. 19, you see, in front, the transversely 

 divided corpus* callosum, the septum pellucidum adjoining, and, 

 at the posterior termination of the latter, the ascending pillars 

 of the fornix. 



Anterior and external to the septum is the head of the 

 nucleus caudatus, which, in this section, has been cut into. Its 

 tail, which, in Fig. 19, passes along the side of the thalamus, 



FIG. 45. 

 Nucleus caudatus dissected out along its whole length. (Diagrammatic. ) 



Ammonshorn. Cornu ammonis. BiecUappen, Olfactory lobe. Ventriltcl, Ventricle. 



can no longer be seen. It lies in the part of the brain which 

 has been removed. A small portion of it only is left, pos- 

 teriorly and exteriorly, near the cornu ammonis. The above 

 cut, which represents a nucleus caudatus dissected out, shows 

 how this condition is brought about. 



The tail of the nucleus caudatus is bent in a curve around 

 the whole brain-axis, and can be traced almost to the apex of 

 the inferior horn of the lateral ventricle. The whole nucleus, 

 therefore, must appear twice on any deep horizontal section of 

 the brain, as is shown by the line a to , in Fig. 45. 



Outside the head of the nucleus caudatus we see some 



