HuBER, SyvipatJutic Nervous System. 127 



neuraxis to some peripheral tissue. Whether all sympathetic 

 neurons are thus connected with the cerebro-spinal system can 

 at present not be positively stated. The evidence is, however, 

 in favor of the supposition that by far the greater majority 

 form the terminal link in such a neuron chain. 



The question has no doubt suggested itself to you, whether 

 the neuraxes of sympathetic neurons ever terminate in other 

 sympathetic ganglia, there to stimulate other neurons, or do 

 they always form terminal links in a neuron chain ? Langley, 

 in several of his communications, denies the possibility of such 

 an ending. In his (88) short account of the sympathetic sys- 

 tem the following statement occurs, — " The ganglia of the sym- 

 pathetic trunk send no fibers to one another." This conclusion, 

 if I understand Langley correctly, is based largely on observa- 

 tions made after the injection of nicotin. In certain ganglia, 

 as for instance the superior cervical, local application of nico- 

 tin stops all the effects produced by stimulating the cervical 

 sympathetic. In Auerbach's and Meissner's ganglia however, 

 Langley and Anderson (89) have shown that ' ' Large doses of 

 nicotin do not paralyze any of the effects which can be ob- 

 tained by stimulating the fibers given off by the inferior mesen- 

 teric ganglion of the pelvic plexus." They add : "It is true 

 that in most cases motor effects on the intestine were dimin- 

 ished to a greater extent than inhibitory or vaso-constrictor ef- 

 fects, this difference was however not constant." They con- 

 clude that the connection v/hich exists between the nerves 

 coming to the intestine and the cells of Auerbach's and Meiss- 

 ner's plexus is of a different nature from that which exists 

 between the pre-ganglionic fibers and sympathetic nerve cells 

 in other parts of the sympathetic ; and, "That the nerve cells 

 of the plexuses of Auerbach and Meissner do not belong to the 

 cells of the sympathetic but are cells of a different nature." 



KoUiker (34) has already drawn attention to the erroneous- 

 ness of this last conclusion, and Dogiel (55) has shown that in 

 mammalia the cells of Auerbach's and Meissner's plexuses are 

 in shape and structure like the ganglion cells in other sympa- 

 thetic ganglia. Dogiel (55) has further shown that medullated 



