GENERAL CONFORMATION AND HISTOLOGY OF BRAIN. 



37 



can be seen. The outer portion the lenticular nucleus lies 

 deeper, and is covered with medullary masses, which pass over 

 it into the internal capsule. We could expose it by opening 

 downward outside of the nucleus caudatus, but you will get a 

 better idea of its form if a frontal section is made transversely 

 through the whole brain at the point in Fig. 19 where the thala- 



FIG. 21. 

 Frontal section through the adult brain. Explanation in the text. 



Balken, Corpus callosum. Uarklager, White substance. 



mus begins, just behind the thickest part (caput) of the nucleus 

 caudatus ; that is to say, just behind the ascending pillars of the 

 fornix. 



It is not difficult to understand the cross-section (Fig. 21) 

 if we keep in mind the conditions shown in Fig. 6. The brain- 

 wall is decidedly thicker than at the fcetal period, but the corpus 



