No. 3.] NERVOUS SYSTEM OF CYNTHIA PARTITA. 107 



cells it was found that not the hollow portion of the tube but 

 its wall seemed to make up the axis cylinder. In specimens 

 killed in Von Rath, Hermann, Flemming, or sublimate, fluids 

 which gave much less distortion and shrinkage, the clear area 

 between the so-called walls of the nerve tubes is seen to be 

 filled with fine fibrils. These fibrils in chromic material are 

 evidently shrunken and lie close to the wall of the "tube." 

 Indeed some specimens show the fibrils lying against the wall 

 of the "tube." 



Centrosome and Sphere in the Tunicate Ganglion Cell. 



In nerve cells containing excentric, flattened, or invaginated 

 nuclei, as well as in many cells not showing this nuclear dis- 

 turbance, were found the structures which I have taken homol- 

 ogous with the centrosome and sphere of Von Lenhosseck, 



Fig. 5. —Centrosome and sphere in ganglion cells {Cynthia). i, Von Rath; 2, 3, 5, 6, 8, 

 Flemming; 4, Perenyi; 7, chrom-oxalic. Iron-haematoxylin. Camera drawings. 

 ■J5 X oc. 6 (Zeiss). 



Dehler, Lewis, McClure, and others. In most general terms 

 the structure can be spoken of as consisting of three parts. 

 Beginning from the outside and going inward we have first : 

 an outer coarsely granular zone — the granular zone of 

 McClure and Lewis. The area of this zone varied greatly (see 



