122 Journal of Comparative Neurology. 



neuraxes of the sympathetic neurons of the gangh'on ( post- 

 gangHonic fibers ) are stimulated directly. In discussing this 

 point with Prof. Cushney, and taking into consideration, 

 what is now well known concerning the minute anatomy of the 

 sympathetic ganglia, with especial reference to the histological 

 connection between the central, the cerebro-spinal fibers, and the 

 sympathetic cells, we have reached the conclusion that nicotin 

 does not paralyze primarily the sympathetic cells, but rather 

 the intra-capsular, peri-cellular baskets of the central fibers. 

 This conclusion is based largely on the analogy which exists 

 between the physiological action of certain drugs — curare, 

 spartin and others — and nicotin. 



For example, it is well known that curare paralyzes the 

 motor endings in striated muscle. That the ending, and not 

 the muscle or the cell body of the neuron terminating in said 

 muscle is paralyzed can easily be shown by well known phys- 

 iological experiments, which it will not be necessary to mention 

 at this place. Langley and Anderson (83) have shown that 

 curare in large doses paralyzes also "the cells of the ciliary 

 ganglion." That is, when large doses of curare are injected, 

 stimulation of the Ilird cranial nerve does not cause constric- 

 tion or closure of the pupil. 



Langley and Anderson (83) have also shown "that ten 

 milligrams of nicotin is sufificient to paralyze the nerve-ending 

 of the extrinsic muscles (striated muscles) of the eye. But 

 this amount of nicotin is not sufficient in the rabbit and rarely 

 in the cat, to paralyze the nerve endings in other muscles of 

 the body. " Nicotin, of course, also paralyzes the ciliary gan- 

 glion, it being a sympathetic ganglion, as was first shown by 

 Retzius. ( It is of interest to note in this connection that a 

 smaller dose of curare is required to paralyze the motor end- 

 ings in the extrinsic eye muscles, than in other muscles of the 

 body.) Langley and Dickinson (84) found that "the motor 

 nerve-endings are paralyzed in the cat by 10 to 15 m. g. of nic- 

 otin, that rather more is required in the rabbit, and consider- 

 ably more in the dog." The analogy between the action of 

 nicotin and curare is therefore worthy of notice. They both 



