ON THREE POINTS IN THE NERVOUS ANATOMY 

 OF AMPHIBIANS. 



J. S. KiNGSLEY. 

 With three figures. 



In my studies of the head of Amphiuma, which I hope to 

 have completed at an early date, I have found it necessary to 

 make comparisons with the results of other observers, and in 

 some cases to repeat their observations, especially in those cases 

 where Amphiuma presented features not easily reconciled with 

 the conditions existing in other foms. 



For this purpose I have had to go over the results ob- 

 tained by von Plessen and Rabinowicz in their classic "Die 

 Kopfnerven von Salamandra maculata. " Studying latvae of 

 this species, varying between two and a half and three centi- 

 metres in length, these authors figure and describe a commis- 

 sure as existing between the ramus palatinus of the facial and 

 their supra-maxillaris superior of the trigeminal, a condition 

 which is not easily reconcilable with what I find in Amphiuma 

 nor with what other authors find to exist in the Urodeles. To 

 test the question as to whether Salamandra maculata was unique 

 in this respect I sectioned a larva of twenty six millimeters 

 and plotted the sections in the same manner as these authors 

 did. As a whole I can confirm their results, but there are a 

 few features which need correction. In their figures they give 

 a small nerve, designated by the letter z, forming a ramus com- 

 municans between the mandibularis and the maxillary (their 

 supra-maxillaris superior) nerves. In my studies this ramus 

 communicans also occurs, but, instead of its being very small it 

 is fully as large as the branch from the " nebenganglien " with 

 which it connects. Detailed study of many Urodeles shows 

 that the maxillaris must be regarded as a compound nerve, 

 with both facial and trigeminal components. See fig. i. 



