Herrick, JVerves of Szluroid Fishes. 179 
the present writer, among others (see the appended bibliog- 
raphy) and to the article ‘‘Cranial Nerves” in the second edi- 
tion of Wood’s Reference Handbook of the Medical Sciences 
(Vol. III, now in press) for the point of view regarding the 
nerve components from which the present study takes its de- 
parture. 
No types known to me offer so many advantages for the 
study of this problem as.the North American cat fishes, for 
these fishes possess both types of sense organs in exceptional 
abundance, diversity of forms and extent of distribution over 
the skin and they are moreover entirely without scales. The 
embryological method appears to be the most favorable avenue 
of approach ; but believing that studies in development should 
be preceded by a thorough knowledge of the adult structures 
involved, I have undertaken a preliminary study of the cuta- 
neous sense organs and their innervation. Finding the accounts 
in the literature often contradictory and always incomplete on 
points of greatest importance from this point of view, this work 
has grown into greater proportions than at first anticipated, and 
this must be my apology for presenting so large a mass of de- 
tailed descriptive matter, much of which is after all but a repe- 
tition of what others have found before me. : 
The nerves and sense organs of Ameiurus catus have been 
incidentally referred to by ALLis (’89 and ’97) ; the lateral line 
canals and their nerves have been more fully described by Cot- 
LINGE (’95); and this species has been monographed from sev- 
eral different points of view by Wricut, McMurricu, Macat- 
Lum and McKenzigz (’84). Wricut’s account of the nerves 
and sense organs is the most complete and satisfactory and is 
characterized by a keenness of morphological discrimination 
which stands out in pleasing contrast to much of the descrip- 
tive work on the nervous system of the fishes. His account of 
the trigemino-facial ganglionic complex, while very incomplete, 
lays a good foundation for a thorough understanding of the 
components of these nerves. It is upon this foundation that 
the present contribution is based, my prime motive being the 
determination of the exact relations between the several types 
