No. I.] SYMPATHETIC GANGLIA OF VERTEBRATES. 37 



down, stained, and remounted). The latter figure may serve to 

 show that the end fibrillae shown in PI. Ill, Fig. 4, terminate 

 between nuclei found within the capsule. In all instances (see 

 also PI. Ill, Figs. 6 and 7) where this more complicated end- 

 ing was observed, the cell body of the sympathetic cell seemed 

 imbedded in these nuclei ; some of which, no doubt, belong to 

 the cells of the capsule ; others, if my observations are to be 

 relied on, are within the capsule and seem to be grouped more 

 particularly about that portion of the sympathetic cell from 

 which the neuraxis arises. The number of the nuclei varies ; 

 in PI. Ill, Fig. 6, sketched from a cell obtained by teasing a 

 small ganglion, and which was completely isolated from the 

 surrounding structures, I estimated that ten to twelve nuclei 

 are within the capsule. The capsule enclosing this cell {c) was 

 very clearly made out. The branches of the nerve fiber ending 

 within the capsule are clearly shown in the figure, they alone 

 being stained in methylene blue, the other structures taking 

 the alum carmine. In PI. Ill, Fig. 5, above referred to, and 

 in PI. Ill, Fig. 7, the number of these nuclei is far greater. 

 In the latter figure, which was also sketched from a teased 

 preparation, may be seen the neuraxis of a large medullated 

 fiber, from which two non-medullated collateral branches {a! and 

 a") are given off, these terminating within the capsule of the 

 sympathetic ganglion cells {A and B) in a system of varicose 

 end branches, the majority of which end between the intra- 

 capsular nuclei. 



It may be of interest to note that Arndt (8) has diagrammed 

 a cell which resembles very closely the one shown in PL III, 

 Fig. 6. The cell referred to is reproduced by him in PI. XIV, 

 Fig. 38. Arndt, in his account, describes it as coming from 

 a sympathetic ganglion of Perca, macerated in a jL^ solution 

 of acetic acid. 



I have not been able to formulate any definite conclusions 

 as to the nature of the nuclei above mentioned. I beg, how- 

 ever, to be allowed to give expression to a hypothesis which 

 has often suggested itself in studying the preparations made 

 from the sympathetic ganglia of fishes, but more particularly 

 from similar preparations made from Reptilia ; namely, that these 



