THE GRAY MATTER. 



617 



partitions of white matter into three parts (Gp', Gp'\ Pt), and of which 

 we shall speak directly as the nucleus lenticularis. 



FIG. 139. 



Diagrammatic Outline of a Transverse Dorso-ventral Section through the Right Hemisphere 

 (Man), at Level Posterior to the Knee of the Internal Capsule. (Sherrington.) Natural size, 

 Nc, nucleus caudatus; in the upper part of the figure the section of the nucleus is through the 

 narrower portion which succeeds the wider front end or head ; in the lower part of the figure the 

 section passes through the tail of the nucleus near its end, and this portion of it has for the sake 

 of clearness been sundered from the gray matter at Na, nucleus amygdalae, more distinctly than 

 in reality is the case. Gp', Gp", globus pallidus, seen here in two segments, and Pt, putarnen of 

 nucleus lenticularis ; an, the anterior; in, the inner ; and In, the lateral nucleus of the optic thala- 

 mus ; at II is seen the " latticed layer" lying next to dp, the posterior limb of the internal capsule 

 aud containing many strands of fibres which mingle with it. In the thalamus between the ante- 

 rior and internal nuclei on the one hand and the lateral nucleus on the other is a layer shaded 

 less deeply in the figure, representing the internal medullary lamina of the thalamus. consisting 

 largely of white matter. Other collections of white matter within the thalamus are Vb, the bun- 

 dle of Vicq. d'Azyr, and F', the lower end of the anterior pillar of the fornix ; F, the upper end 

 of the anterior pillar of the fornix, below cc the corpus callosum ; C.sb, corpus subthalamicum; 

 forming a fairly continuous mass with the thalamus; Sn, substantia nigra ; cl, claustrum ; ce, 

 external capsule ; Ca, terminal portion of anterior commissure ; In, the instila or island of Reil ; 

 Iv, lateral ventricle ; l.v.d., descending horn of lateral ventricle ; V. 3, in the position of the third 

 ventricle; the outlines of the cavities are made diagrammatically distinct by thick black lines; 

 Op optic tract ; P P, parietal lobe ; T, temporal lobe. 



If instead of taking a transverse we take a longitudinal dorso-ventral 



