NERVE TISSUE 133 



and separates the neurolibrils. It is believed by some to be like 

 the fibrils, continuous throughout the cell body and processes, by 

 others to be interrupted at certain points in the axone (see p. 142). 



(3) The chromophilic bodies (Fig. 75) are granules or groups of 

 granules which occur in the cytoplasm of all of the larger and of 

 many of the smaller nerve cells. They are best demonstrated by 

 means of a special technic known as the method of Nissl (page 39). 



Fig. 77. — Body of Large Pyramidal Cell from Cortex of Cat. Silver Method of 

 Cajal. Shows nucleus pale and arrjingement of neurofibrils within the cell; a, axone; 

 h, main or apical dendrite. (Cajal). In this picture the neurofibrils are shown as 

 anasttmioslng. 



When subjected to this technic, nerve cells present two very dif- 

 ferent types of reaction. In certain small cells the amount of 

 cytoplasm is extremely small and only the nuclei stain with the 

 Nissl method. Such cells aire found in the granule layers of the 

 cerebellum, olfactory lobe, and retina. They are known as caryo- 

 chrome cells, and apparently consist wholly of neurofibrils and peri- 

 fibrillar substance. Other cells react, both as to their nuclei and as 

 to their cell bodies, to the Nissl stain. These cells are known as 

 somatochrome cells. Taking as an example of this latter type of cell 

 one of the motor cells of the ventral horn of the cord and subjecting 



