1 Journal of Comparative Neurology. 



tion of the morphological questions invoved could not fail to be of 

 value no matter what the type under investigation. 



In the study of the more minute ramifications gross dissections 

 were supplemented by microscopic reconstructions in wax and by 

 means of plats made on cross-section paper. The application of both 

 these methods to the eye muscle nerves has yielded results whose accu- 

 racy and completeness contrast very favorably with the more crude re- 

 sults of the earlier investigators. These arrangements conform more 

 closely to those of the lower Amphibia than to those of the bony fishes. 

 The comparisons made with the Amphibia throughout are of the great- 

 est interest. 



Probably the most striking morphological feature brought out by 

 these investigations is the discovery of a new cranial nerve in Protopterus 

 which is not found in other vertebrates, a preliminary notice of which 

 appeared in the Anatomischer Anzeiger last year. It arises near the 

 median line in front of the optic nerve at the extreme cephalic end of 

 the preoptic recess. It courses forward along the base of the brain 

 near the median line, and upon emerging from the cranium takes its 

 position at the ventro-mesal angle of the olfactory nerve. This it main- 

 tains up to the nasal membrane. It terminates in the skin of the upper 

 border of the external nares. Like the olfactory nerve it is nonmedul- 

 lated. It has nothing to do with the recessus neuroporicus [lobus ol- 

 factorius impar] as it lies at the ventral end of the lamina terminalis. 

 Dr. Pinkus very wisely declines to discuss its morphology until there is 

 a better observational basis. No safe conclusions can be drawn until 

 more is known of its inner course and connections. 



In the discussion of the trigeminus and facial systems many valu- 

 able points are brought out. The morphological conclusions are based 

 upon and in the main agree with those expressed by Strong in his 

 earher papers. In the Amphibia two types must be distinguished, the 

 aquatic and the terrestrial, as indicated in the following table. 



Type I. 

 Urodele larvae, Perennibranchiata, Derotrema, and Aquatic Salamanders, 

 The Trigeminus posseses 



1. R. maxillaris, which subdivides into 



a) r. maxillae inferioris, 



b) r. maxillae superioris, 



2. R. ophthalmicus profundus. 

 The Facial consists of 



1. R. hyoideomandibularis, 



2. R. lateralis, which subdivides into 



a) R. ophthalmicus superficalis facialis, 



