THE BRAIN 



of the lateral ventricle, on the roof of which it is prolonged 

 until it finally joins the amygdaloid nucleus. The caudate 

 nucleus, therefore, presents a free ventricular surface covered 

 with ependyma, and a deep surface embedded in the sub- 

 stance of the hemisphere, and for the most part related to the 

 internal capsule. 



Owing to its arched form, it follows that in horizontal 

 sections, below a particular level, it is cut at two points, and 

 both the head and the tail must be looked for in the field of 



, Longitudinal fissure 



Genu of corpus callosum 



Corpus callosum (genu)-' 



Longitudinal fissure 



Caudate nucleus 

 Caudate nucleus (in section) 

 Anterior horn of lateral ventricle 



FIG. 214. Frontal section through the Frontal Lobes of the Cerebrum. The 

 posterior surface of the anterior part of the cerebrum is depicted so that 

 the reader is looking into the anterior horns of the lateral ventricles from 

 behind. 



section (Fig. 213). In frontal sections posterior to the amyg- 

 daloid nucleus it is also divided at two places. 



Nucleus Lentiformis. This mass of grey matter lies on 

 the lateral side of the caudate nucleus and the thalamus, and 

 is, for the most part, completely embedded within the 

 medullary substance of the cerebral hemisphere. It does not 

 occupy so large an area as the nucleus caudatus. Indeed, it 

 presents a very close correspondence in point of extent with 

 the insula on the surface. 



When seen in horizontal section (Fig. 213) it presents a 

 shape similar to that of a biconvex lens. Its medial surface 



