I04 



HUNTER. 



[Vol. II. 



specimens the nuclei do not occupy proportionately as much 

 space as in the smaller cells, but still much more space than 

 in cells of corresponding size in older specimens. The nucleus 

 is rarely indented, usually ovoid or nearly spherical, is rich in 

 chromatin, and contains a small nucleolus. In general the con- 

 dition is more nearly that of the adult ganglion cell (Fig. 2). 



The Cell Process and Nerve Trunks. 



The cell process is undoubtedly fibrillar (Schultze, Flemming, 

 Pfliige). A decided entrance cone was frequently observed. 

 In other cases the fibrils appeared to enter the cell-body, and 

 spread out in the cortical part of the cell. This was especially 

 noticeable in material killed in Flemming. In rare cases 

 where only one large fiber or bundle of fibrils seemed to enter 



the cell, it would 

 be traced for some 

 little distance. 

 This may be sim- 

 ilar to the intra- 

 cellularaxis cylin- 

 der of Binet ('94). 

 The structure 

 of the cell proc- 

 ess in the cen- 

 tral system was 

 extremely diffi- 

 cult to make out, 

 but a satisfactory 

 picture could be 

 obtained from 

 young specimens. In such animals the connective-tissue sheath 

 surrounding the central ganglion is not developed, and ganglion 

 cells are frequently found projecting into the loose connective 

 tissue surrounding the ganglion. Indeed they are often near 

 nerve trunks entirely free from the cell mass of the ganglion. 

 Such a cell is shown in Fig. 3. The nerve trunk of which 

 it is a part would be shown in the next section. The fibrillar 



Fig. 3. — Section parallel and exterior 

 to nerve trunk, showing outlying 

 ganglion cell. Young specimen. 

 g.c, ganglion cell; e., epithelium of 

 peribranchial cavity ; /. leucocyte ; 

 n.f., nerve fiber. Von Rath. Iron- 

 haematoxylin. yV x oc. 6 (Zeiss). 



