184 



HISTOLOGY 



masses would be clearly shown if the section should be exposed to the 

 action of trypsin, when the other cell parts would be digested and leave 

 only the neurochondria, which could then be studied alone and apart 

 from any of the other cell-organs. 



Certain of the tigroid masses are remarkable in their position or size. 

 Some of them form a cap-like structure on one or more sides of the 

 nucleus. Some extend out into the dendritic processes, always, however, 

 becoming narrower and longer as they are found farther from the cell 

 body. Their absence in the neurite and implantation cone must be 



ca.n 



FIG. 161. Giant dorsal nerve cell from the spinal cord of the marbled angler, Pterophryne 

 histrio. n., nucleus; cy., cytoplasm; ca., capillaries; ca.n., nuclei in the capillary walls. 



looked on as an economy of space, the parts in question being too 

 small to accommodate the tigroid masses which can just as well.be 

 kept in the cell body. 



In the huge dorsal nerve cells of the young of the winter flounder a 

 peculiar set of chromatic bodies make their appearance, both on the edge 

 of the implantation cone and extending somewhat out into the fiber 

 (Fig. 1 60). These are probably a developmental feature. They are much 

 larger than the permanent tigroid masses in the cell and are very 

 compact and smooth in outline. They possibly are reserve stores of the 

 chromaphyllic substance and give up their material to the growing and 

 forming tigroid bodies. Their smooth outline and compact structure 

 make it possible that they belong to some other group of granules in 

 the nerve cell. Such essentially different granules are found in parts 



