260 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



one another, as in Figure 48. Near the nucleus, however, they pass 

 over into a network, whose closeness and intricacy it is impossible to 

 represent adequately. The nucleus seems to be crowded over toward a 

 protruding side of the cell, while the network as a whole passes in a 

 direct course through the cell. There is something of a network all 

 around the nucleus, but except on one side it is comparatively inconspic- 

 uous. At any given focus in the network one sees a set of irregularly 

 distributed " knots," which disappear on focusing and give place to a 

 different set. Between the knots run fibrils whose thickness is less than 

 the thickness of the knots. The fibrils at the knots arise in such a way 

 as to preclude the idea that the branching is all distad, the knots being 

 tied together in all directions. There is thus produced the appearance 

 of an irregular network whose meshes vary much iu size and shape. The 

 knots do not appear to be the result of accidental fusion or crossing of 

 fibrils, for such relations would require the fibrils arising at the knots to 

 be an even number. This cell is cut off obliquely near the nucleus so 

 that its neurite is not visible. 



The network appears likewise in cross sections through the nucleated 

 part of the cell. Figure 51 i-epresents such a section through two cells. 

 In one the network is mainly on opposite sides of the centrally placed 

 nucleus. In the other, it is largely confined to one side of the cell. We 

 do not find here that there are two networks, a circum-nuclear and a 

 peripheral, connected with each other by radial fibrils, such as Apathy 

 ('97) described for the ganglion cells of the leech. 



The neurites which show fibrils are by no means numerous, and there 

 is, therefore, great danger of mistaking radiculae without fibrils for neu- 

 rites. Figure 54 represents a clear case of a cell whose neurite-process 1 

 lies nearly parallel to the plane of the section. The most of the neurite 

 is cut away ; but the arrangement and direction of the fibrils can be 

 seen. In this cell the main path of the fibrils lies, as was determined by 

 focusing, between the eye of the observer and the nucleus. Immediately 

 proximal to the nucleus there is a series of knots from which fibrils rise 

 upward and take a course as if to pass over the nucleus. Clearly these 

 fibrils were cut away with the section preceding the one shown in the 

 figure. Midway between the nucleus and the neurite there are some 

 good examples of the kind of meshes which the fibrils make. Then, 

 running out into the narrow process of the cell, the fibrils take a more 



1 I have used the term " neurite-process " to indicate that projection of the cell 

 body which merges into the neurite. The fibrils often exhibit a network in this 

 process, but not in the neurite proper. 



