NoRRlS, Nerves of Ajiiphnima. 547 



is an appearance of fibers being given off from the r. communicans 

 but careful search shows that all of the fibers so given offcome from 

 the VII nerve. I can find no indication of motor fibers associated 

 with the posterior part of the anastomosis. Druner figures the 

 anastomosis as giving off fibers to the anterior portion of the 

 depressor mandibulae muscle the direction of the fibers being such 

 that the only interpretation that can be given to the figure is that these 

 fibers come from the IX-X complex, I have sought carefully in 

 all my series of sections, the material being so sharply differentially 

 stained that nerves such as figured by Druner could not escape 

 detection, and I find not a suggestion of the presence of such 

 fibers. In one series of sections, sagittally cut, with most excellent 

 differentiation of components, the motor fibers from the VII 

 nerve that usually run posteriorly along the smaller dorsal portion 

 of the r. communicans are everywhere distinct from it, and not 

 a single twig is given off from the r. communicans until the r. 

 jugularis is reached (figs. 15 and 21). 



In a preliminary communication (1908) I stated that the r. 

 communicans contains communis fibers. While I am not yet 

 ready completely to retract that statement, I now regard the pres- 

 ence in the r. communicans of such fibers as highly improbable. 



We may summarize the foregoing statements regarding the 

 ramus communicans in Amphiuma as follows: (i) Druner's 

 contention that the r. communicans is exclusively motor will not 

 stand. A large general cutaneous component enters the ramus 

 from the second IX-X root. The general cutaneous fibers in the 

 VII nerve can come from no other source. (2) That the r. 

 communicans contributes fibers to the r. jugularis does not indi- 

 cate that these fibers are motor. The branches that receive 

 fibers from the r. communicans are those that contain general 

 cutaneous fibers; they must receive them from that source. (3) 

 Druner's statement and figure showing branches given off from 

 the r. communicans to the anterior division of the depressor mandi- 

 bulae muscle are incorrect. It has been seen in some instances 

 that this cannot possibly be true; in other cases the fibers so given 

 off do not originate from the IX-X ganglion, but come from the r. 

 hyomandibularis, that is, are not to be considered a part of the 

 r. communicans. (4) That motor fibers enter the r, communi- 

 cans from the IX-X ganglion has not been demonstrated, and is 

 highly improbable. (5) The r. communicans is composed of 



