XXX.] THE BRAIN. 



/. The 1st layer of the cortex, consisting of a 

 fine network of fibrils showing a few very 

 small cells. 



g. Blood vessels may be made out in all por- 

 tions of the cortex, they are usually most 

 conspicuous in the outer layers of the cortex 

 running into it from the pia mater. 



3. Prepare sections of a lobule of cerebellum ex- 

 tending from the surface to the inner white 

 substance and at right angles to the direction of 

 the folds. The hardening, staining, etc., are the 

 same as for the cerebral cortex. Observe 



a. The inner strand of medullated nerve fibres 

 spreading into 



b. The nuclear layer, formed mainly of small 

 cells closely packed together; these cells 

 have a very small amount of cell substance, 

 so that probably their deeply stained nuclei 

 only will be seen. 



c. A single layer of large somewhat globular 

 cells (Purkinje's cells); each has a large peri- 

 pheral process which will be seen to branch, 

 and the branches to branch again and so 

 on, eventually extending as fine branching 

 fibrils nearly to the surface of the cortex; 

 close to the surface the fibrils become lost 

 to view. Since the branches, especially the 

 larger ones, run to some extent laterally, the 

 processes from neighbouring cells will be 



