chap, xviii.] CEREBRUM AND CEREBELLUM. 



'57 



for each convolution 

 branches off, and, (6), 

 the commissure of white 

 matter between the two 

 hemispheres, i.e., the 

 corpus callosum and 

 anterior commissure. 

 The centrum ovale again 

 consists of tracts of 

 medullated nerve-fibre, 

 which connect (a) the 

 convolutions of the same 

 hemisphere with one 

 another, and (b) such as 

 pass between the con- 

 volutions on the one 

 hand, and the thalamus 

 opticus, the pons, and 

 medulla on the other. 

 These tracts pass by the 

 internal capsule (see 

 below) to the thalamus 

 opticus, and to the crus 

 cerebri. 



The grey cortex con- 

 sists, according to Mey- 

 nert, of the following 

 layers (Fig. 92) : (1) a 

 superficial layer of grey 



Fig. 92. Vertical Section 

 through the Grey Matter of a 

 Cerebral Convolution. 



a, Superficial layer; 6, closely- 

 packed small ganglion cells ; c, the 

 layer of the cornu Ammonia, this 

 being the principal layer; d, the 

 " granular formation," small 

 niultipolar ganglion cells; , the 

 layer of spindle-shaped ganglion 

 cells. (Meynert, in Strieker's 

 Manual.) 



