CoGHiLL, Struciiire of the Nerve Cell. 177 



fibrillar structure. The fibrillae are made up of rows of neurosomes 

 connected by slender protoplasmic filaments. Generally, around the 

 periphery of the cell body the meshes are larger than in other regions. 

 Around the nucleus and in the cone of origin they become more nar- 

 row and very much elongated. A more pronounced modification of 

 this character is found in the axone so that the reticular condition is 

 difficult to see. In the axone, however, the neurosomes stain brighter 

 than elsewhere. Especially is this true of the neurosomes of the axone 

 terminals, where they are also larger than in other parts of the cell. 

 The dendrites contain a relatively small amount of the ground sub- 

 stance and the ireurosomes stain more faintly than in the axone. This 

 fact enables Hatai to dififerentiate the finest dendritic branches from 

 the contiguous terminals of the axone. Even in the gemmules he 

 demonstrates the neurosomic reticulum as continuous with that of the 

 rest of the cell, but he finds that its neurosomes differ both in size and 

 staining reaction from those of the axone terminals. He concludes that 

 there is no continuity of the so-called fibrillar structures between the 

 nerve cells. 



Now Hatai finds that a number of these neurosomic filaments 

 may mat together into thicker strands and that several of these strands 

 in some cases form a complicated network around the nucleus. Such 

 a network does not appear in the cone of origin or in the periphery of 

 the cell body. He homologizes this network with the intracellular 

 anastomosing fibrils of Apathy and also with the eudocellular network 

 of GoLGi. Thus Hatai resolves the neurofibrils of Apathy into the 

 protoplasmic elements of the cell and denies that they pass continuous- 

 ly from cell to cell. The diffuse nets in the neuropil and pericellular 

 nets also may be resolved into the reticulum of axone terminals which 

 would be strictly protoplasmic and not extra-cellular, derived 

 substance. 



Moniliform Condition of the Dendrites. 



Since Dogiel's discovery of the dendritic varicosities in the cells 

 of the retina this feature of the nerve cell has held an important place 

 in neuro-cytology. Among the most comprehensive contributions upon 

 the subject are those of Soukhanoff. This author made four exper- 

 ments by ligature of the abdominal aorta, three upon guinea pigs 

 which died from the experiment in from one-half to twenty-four hours, 

 and one upon a rabbit which was killed after twenty-four hours. In 

 these experiments he found that the diminished blood supply had pro- 

 duced a very rapid modification in the nerve cell, varying directly in 



