HISTOLOGY. 



are not separate, but go to make up morphological units, each 

 fibre being connected with a cell. What Apathy has shown 

 is, that these morphological units are sometimes connected, 

 and that neurofibrils pass in the protoplasm from one to the 

 other. 



The body of the nerve cell shows certain finer structures 

 which have been the subject of much investigation in the last 

 few years. All nerve cells possess a fibrillar structure, in the 

 cell body as well as in the processes. The fibrils of the axone 

 are more or less a continuation of those of the cell body. Here 

 they run in all directions, often concentrically, and form a sort 



FIG. 72. 



Axone 



Axone 



End apparatus of axones from the trapezoid nucleus of a rabbit. (Prepared by S. Meyer's 

 methylene-blue method.) x 700. 



of network, especially in the middle of the cell. The proto- 

 plasm of the cells contains numerous very fine, deeply staining 

 granules (chromatophile). These granules are usually spindle- 

 shaped, and are called Nissl bodies or tigroid bodies (Lenhos- 

 si'k). They are found also in the dendrites, but not in the 

 axone hillock (Fig. 73). Their relation to the fibrils of the 

 cell body is not yet explained. Some authors claim that they 

 are connected closely with the fibrils, others that they are inde- 

 pendent and lie in the spaces between the fibrils. A few 

 authors regard them as artifacts produced on the death of the 

 cell (Held). Some believe that they have an important trophic 



