Herrick, Cranial Net-i'es of the Cod Fish. 293 



much smaller and they rest in a layer of thicker epidermis, 

 through the whole thickness of which they do not extend, so 

 that they do not reach the dermis. The nerve fibers are ex- 

 ceedingly fine and in my specimens are so thoroughly decolor- 

 ized that it is usually impossible to see them at all. When they 

 appear it is only as delicate colorless filaments running from the 

 base of the organ to the dermis. The organs are never flat 

 topped, but always pointed at the apex and project very slightly 

 above the general surface of the skin. They differ from the 

 terminal buds of the cyprinoids and siluroids in that there is no 

 dermal papilla rising up through the lower layers of the epidermis 

 for them to rest upon, and they are broader, nearly globular with 

 a pointed apex, instead of narrowly flask-shaped. A few scat- 

 tered terminal buds were found on the pectoral fin similar to 

 those on the pelvic. 



My sections do not afford an absolute demonstration that 

 the communis fibers which enter the paired fins supply the 

 terminal buds there found. Nevertheless the fact that terminal 

 buds are not found on these fins in such fishes as Menidia, 

 which do not have the corresponding communis nerves, to- 

 gether with the known correlation of terminal buds and com- 

 munis nerves in every other case of which we have accurate 

 knowledge, give such an assumption the highest degree of 

 probability. 



The sections unfortunately do not extend far enough caudad 

 to enable me to study the dorsal and anal fins. Yet I have no 

 doubt that the distribution of their communis nerves is strictly 

 analogous to that of those just considered. 



/J. The Pre-vagal Sympathetic System. 



Tiie sympathetic system in its cephalic part is much more 

 highly specialized in Gadus than in Menidia ; nevertheless its 

 relations to the trigemino-facial complex arc clear in their main 

 outlines. Since it lies almost wholly internal to the other nerves 

 of the complex, it is impracticable to sketch it upon the recon- 

 struction. The series of transections will, however, illustrate 

 its course. 



