I02 STRONG. [Vol. X. 



II, No. I, July, 1888), occur the following sentences : "Much 

 remains to be done in respect to the peripheral distribution 

 of the component parts of the several cranial nerves. Only 

 after this has been thoroughly worked out can we certainly 

 determine the homologies of the cranial nerves and their 

 segmental relations in the Amphibia. The present results go 

 far enough to show that the determination of definite nuclei 

 corresponding to definite peripheral sensory and motor areas is 

 well within the range of possibility. In fact, the provisional 

 character which I have given to some of the conclusions here 

 reached is chiefly due to the close connection between several 

 of the cranial nerves at, or close to, their exit, which makes 

 it necessary to follow each component bundle in continuous 

 sections peripherad to a point where their further distribu- 

 tion can be traced macroscopically. This, I believe, is possible 

 with several of the nerves, but has not as yet been successfully 

 accomplished." 



To supply some of these deficiencies was the immediate 

 aim of this investigation, and, I think, some of the obscure 

 points mentioned by Osborn in his paper are satisfactorily 

 cleared up. While very much remains to be done on the 

 forms here investigated, yet a firmer basis has been acquired 

 on which to make comparisons with the cranial nerves in other 

 forms and to draw conclusions as to their nature. 



In the opinion of the writer much of the embryological work 

 upon the cranial nerves has been very defective and even mis- 

 leading, owing to the fact that their adult distribution and 

 function had not first been accurately worked out. I would 

 venture to predict that more light can and will be thrown 

 upon the nature of the cranial nerves in the immediate future 

 by means of anatomical and histological than by purely 

 embryological research. 



This paper is by no means a monographical account of the 

 cranial nerves of Amphibia, but will be confined principally to 

 the V, VII, IX, and X nerves. Other nerves will be included 

 in the description as they come into connection with these. 



The types upon which the bulk of the work has been done 

 and upon which the description is based are several common 



