128 Journal of Comparative Neurology. 



fibers, which end in peri-cellular baskets, can be traced, into these 

 ganglia. These observations I can corroborate for the cat and 

 rabbit and also for the reptilia (Chelydra serpentina). I have 

 also found peri-cellular baskets ; the number has however been 

 relatively small. I should infer that not all the sympathetic 

 neurons of Auerbach's plexus are in connection with medullated 

 fibers through peri-cellular baskets. In frogs and fishes the 

 nerve cells of Auerbach's plexus have often been stained, but 

 so far no peri-cellular baskets have been observed. 



The diminution in the motor effect, observed after the in- 

 jection of nicotin and subsequent stimulation of the fibers 

 given off from the inferior mesenteric ganglia and those of the 

 pelvic plexus, may be due to a paralysis of peri-cellular baskets 

 in Auerbach's and Meissner's plexus. The fact that not all the 

 effects were lost after the injection of nicotin may be explained 

 in one of two ways — (i) Some of the nerve fibers in Auer- 

 bach's and Meissner's plexuses may not be connected with nerve 

 cells beyond the inferior mesenteric ganglia, in which case nico- 

 tin would not paralyze their action. (2) Some of the neuraxes 

 of the neurons in the inferior mesenteric ganglia may termi- 

 nate in the peripheral ganglia of Auerbach's and Meissner's 

 plexuses. 



I have previously stated that evidence of the ending of 

 neuraxes of sympathetic neurons on the protoplasmic branches 

 of other sympathetic neurons was to be had from a study of 

 thin sections of methylen-blue stained sympathetic ganglia, 

 and that such neuraxes seemed to come from neurons in more 

 centrally located ganglia. The fact that nicotin experiments 

 lead to a contrary conclusion, seems to me to be insufficient 

 evidence on which to base such a conclusion. If we assume 

 that nicotin paralyzes the end baskets, and not the ganglion 

 cells of sympathetic ganglia, it may readily be seen, that, ow- 

 ing to this selective action of nicotin, the endings of the neur- 

 axes of sympathetic neurons on the dendrites of other sympa- 

 thetic neurons may escape paralysis by nicotin, as the termin- 

 ations of the neuraxes of sympathetic cells in non-striated or 

 heart muscle or in gland tissue escape paralysis. It would seem 



