248 'Journal of Comparative Neurology and Psychology. 



and tenth nerves. The sections were stained in Weigert's haema- 

 toxylin after mordanting with one-half saturate solution copper 

 acetate. 



THE OLFACTORY NERVE. 



My studies of the description of the olfactory nerve of Triton 

 by BuRCKHARDT ('91) led me to expect a sharp division of the root 

 ot this nerve into two fascicles. My serial sections have disap- 

 pointed me, however, in this, for I find the two divisions of the 

 nerve quite as obscure in their relations in Triton as they are in 

 Amblystoma. 



In several of my series of sections of Triton taeniatus it is im- 

 possible for me to follow that division of the olfactory nerve which 

 innervates Jacobson's organ to its destination in the olfactory 

 glomeruli and distinguish it sharply from the remainder of the 

 olfactory nerve; but in two of my series it is clear that the branch 

 of the nerve which arises in Jacobson's organ forms the most 

 ventral portion of the olfactory nerve and enters the brain further 

 caudad than the rest of the nerve, and in one case it forms a dis- 

 tinct fasciculus of fibers which is more separated from the rest of 

 the nerve in its proximal part than it is farther out. 



It would seem, therefore, that Triton and Amblystoma are 

 essentially alike in respect to the arrangement and distribution 

 of the olfactory nerve. 



THE EYE-MUSCLE NERVES. 



I. N. Oculomotor ins. — In its ultimate distribution the oculo- 

 motorius of Triton is exactly as in Amblystoma : a r. superior 

 innervates m. rectus superior and a r. inferior innervates m. 

 rectus internus, m. rectus inferior, and m. obliquus inferior. In 

 its position relative to other parts, however, the nerve of Triton 

 is peculiar in this respect, that the r. superior passes ventrally of 

 the r. ophthalmicus profundus V, while in Amblystoma it passes 

 on the dorsal side of this nerve. This is true in every case except- 

 ing one. In this exception the r. superior divides upon leaving its 

 foramen. The more ventral division holds the position which 

 the entire nerve regularly takes, while the more dorsal division 

 passes dorsad on the mesial side of the r. ophthalmicus profundus 



