io8 Journal of Comparative Neurology. 



of type two as above mentioned, are the neuraxes of sensory 

 sympathetic cells. 



The relation of the sensory sympathetic cells to other struc- 

 tures is well shown in Fig. 6 copied from Dogiel's paper. The 

 importance of these observations, in case they receive corrobor- 

 ation, can not be over-estimated. The existence of sensory sym- 

 pathetic cells would explain certain phenomena which have been 

 observed in connection with the sympathetic system. I may 

 mention, for instance, peripheral reflexes and peristaltic move- 

 ments of the intestine, etc. These points will however receive 

 fuller discussion at another time. 



It is not my purpose to discuss fully at this time, the ques- 

 tion of the ending of the neuraxes of sympathetic neurons in 

 sympathetic ganglia. In order to do that it would be necessary 

 for me to mention certain important structures found in sympa- 

 thetic ganglia, to which I have not as yet alluded, and which 

 are more fittingly discussed in the next division of my subject ; 

 and also to refer to some very important physiological work, 

 in connection with the sympathetic system, which has been 

 done by Langley and some of his pupils, the discussion of 

 which I desire to defer until the above mentioned structures 

 have received due attention. Mention may however be made 

 of the fact that Lenhossek (24) has observed, in Golgi prepar- 

 ations made of embryo chicks of the 14th day, sympathetic 

 fibers that enter a sympathetic ganglion from the periphery, 

 there to terminate in free endings, endings which he describes 

 as " simple end-brushes, " the fibrillae of such end-brushes of- 

 ten terminating on cells in small end-bulbs. 



In methylen-blue preparations of the ganglia of the chain 

 taken from mammalia and birds, I have often observed a free 

 ending of branches of non-medullated nerve fibers in sympathe- 

 tic ganglia ; not however on the cell bodies of the sympathetic 

 neurons as Lenhossek would have us believe, but on the den- 

 drites of sympathetic neurons. Fig. 7 shows such an ending, 

 sketched from a moderately thin section of a sympathetic gan- 

 glion of a cat, stained in methylen-blue. As may be seen from 



