38 NERVE COMPONENTS OF BONY FISHES. 



exact. Cole gives (pp. 179-185) a brief but very excellent 

 summary of the more interesting variations of the lateral 

 line canals of different kinds of fishes. 



The numerous writers who have described the lateral 

 canals of the fishes have, as a rule, until recently, devoted 

 no considerable attention to their nerve supply so that the 

 correlation of their results is in many cases a matter of 

 difficulty. Pollard first clearly demonstrated in teleosts 

 the independence of the lateral line system of nerves ; but 

 both his work and that of CoUinge leave much to be desired 

 to complete our knowledge of the innervation of the 

 cutaneous sense organs in the teleosts and especially in 

 the siluroids, which are of special importance in this con- 

 nection. Pending further studies here, it will not be 

 necessary to examine their work in detail. The condi- 

 tions in Lophius, however, as worked out by Guitel ('91), 

 shed some light upon our findings and will be here 

 reviewed. 



The diagram, fig. 6, adapted from Guitel, exhibits the 

 topographical relations of the lateral lines and their inner- 

 vation. In spite of the fact that this system is very 

 highly developed in the head, there are no canals in 

 Lophius. The organs lie in grooves or pits and are over- 

 lapped by the peculiar dermal fringes so characteristic of 

 the Pediculati. The absence of the canals is probably 

 to be correlated with the fact that the skeleton is remark- 

 ably loosely aggregated. Indeed, the older writers classed 

 this among the cartilaginous fishes. Guitel describes 

 several of the head lines as innervated from the trigemi- 

 nus. Of course in the light of present knowledge we 

 must relegate these branches to the facialis, and with this 

 correction the homologies of his lines are clear. 



In Lophius there is but one lateral line on the trunk, 



