254 



THE NERVOUS SYSTEM 



of the inferior horn and extends rostrally as far as the amygdaloid nucleus. 

 Because of its arched form it will be cut twice in any horizontal section which 

 passes through the main mass of the corpus striatum, and in any frontal section 

 through that body behind the amygdaloid nucleus (Figs. 185, 189, 191). The 

 head of the caudate nucleus is directly continuous with the anterior perforated 

 substance; and ventral to the anterior limb of the internal capsule it is fused with 

 the lentiform nucleus (Fig. 186). 



The lentiform or lenticular nucleus (nucleus lentiformis) is deeply placed 

 in the white center of the hemisphere and intervenes between the insula, on the 



medialis. 



Stria 

 longitu 



dinalis I lateralis 



Corpus ._ 

 callosum 



Caput nuclei . j 

 caudati * 



I 



Claustrum _j. 



Capsula 

 externa 



Capsula 

 interna 



Nucleus lentifor- 

 mis (Putamen) 



Fibers from 

 the tractus 

 olfactorius 



Gyrus rectusr 



Fissura longi 

 tudinalis 

 cerebri 



Polus temporalis -' 



Fissura longitudi- 



nalis cerebri 

 i_..Gyrus cinguli 



Sulcus corporis 

 callosi 



Cornu anterius 

 ventriculi 

 lateralis 

 ..Vena septi 

 pelluciiti 



_ Septum 

 pellucidum 



~.Fissura cerebri 

 lateral is(Sylvii) 



., Rostrum cor- 

 "poris callosi 



""--- Gyrus sub- 

 callosus 



.Area parolfac- 

 toria (Brocae) 



Fissura cerebri 

 lateralis (Sylvii) 



Fig. 186. Frontal section of the human brain through the rostral end of the corpus striatum and 

 the rostrum of the corpus callosum. (Toldt.) 



one hand, and the caudate nucleus and thalamus on the other (Figs. 185, 191, 

 194). In shape it bears some resemblance to a biconvex lens. Its lateral, 

 moderately convex surface is nearly coextensive with the insula from which it 

 is separated by the claustrum. Its ventral surface rests upon the anterior per- 

 forated substance and the white matter forming the roof of the inferior horn of 

 the lateral ventricle (Figs. 187-189). Its sloping medial surface is closely 

 applied to the internal capsule. The lentiform nucleus is not a homogeneous 

 mass, but is divided into three zones by internal and external medullary lamina. 

 The most lateral zone is the largest and is known as the putamen. The two 

 medial zones together form the globus pallidus. 



