212 Journal of Comparative Neurology. 



and soon become lost. These lateral branches do not 

 anastomose with one another, as can be seen from the magnified 

 camera drawing of Fig. 3, b. They suggest small fibrils com- 

 ing off to form a network, but the closest examination does not 

 show this to be the case, and I am pretty certain that a true 

 inter-epithelial plexus is wanting in Selachians. The unbranched 

 condition of these nerve fibrils is perhaps made more striking 

 by comparing Fig. 2 with Fig. i, which represents a similar 

 preparation from the cornea of one of the osseus fishes (Prio- 

 notus carolinus) where the irregular joining and course of the 

 fibers is apparent, besides in the cornea of the dog-fish the fibers 

 are much larger and thicker. These nerves are covered with a 



Fig. 2. Methylen blue preparation from cornea Sea Robin (Prionotus car- 

 olinus) Zeiss 8 mm. obj. Comp. oc. 4. , Camera. 



sheath which in some places pulls away from the fiber axis 

 proper, leaving a clear space, at the other points swelling up. 

 This sheath however does not in any way resemble the half 

 medullated sheath which Dogiel (/. c.) has described as occur- 

 ring on the corresponding nerves of the human cornea. But is 

 most probably a result of the changes caused in the nerve fibre 

 by the staining process, and which is always characteristically 

 obtained when the blue method is used. 



