256 PROCEEDINGS OF THE CANADIAN INSTITUTE. 
erally considerably more branched and possessing more delicate 
processes than the pigmentary cells of the corium. 
(h) Non-Epithehial Hlements.—Certain small bodies of nuclear 
appearance are met with frequently in the lower layers of the epider- 
mis surrounded by a scanty protoplasm. In size the nuclei agree 
fairly well with those of the amoeboid cells of the connective tissue. 
It is possible, however, that preparation with suitable methods might 
indicate the existence of interepithelial nerves, a matter which de- 
serves investigation since Pfitzner’s' discovery of the nerve endings 
in the epidermis of amphibian larve. 
The following layers are present in the corium of Amiurus which 
does not appear to present any peculiarities in this respect not met 
with in other osseous fishes :— 
(a) The pigmentary or papillary layer. 
(6) The stratified fibrous layer. 
(c) The adipose layer, or sebeutaneous connective tissue. 
(a) The Pigmentary Layer.—The palisade cells of the epidermis 
rest immediately upon a ‘basement membrane, from which in 
hardened preparations they are readily detached, leaving behind 
them the membrane with a distinct jagged edge. The teeth of 
the latter are probably protoplasmic processes serving to connect 
the cells with the underlying structures similar to the ‘intercellu- 
lar bridges’ of protoplasm of the higher cells. In the reticular 
connective tissue which follows the basement membrane are found. 
the vessels and nerves destined for the supply of the epidermis. 
The pigment cells which are so abundant here are very different 
in form from the interepithelial pigment cells (Fig. 1); they are 
much larger and have short lobate processes rarely connected 
in the adult with those of neighbouring cells. This layer would 
not deserve exclusively the name of pigmentary layer in young 
forms, where I find a second almost equally strong layer below the 
stratified fibrous layer, which disappears, however, in the adult with 
the exception of a few scattered cells. 
As the papillee vary much in number in different regions of the 
body the papillary layer is necessarily modified by its projection into 
these structures which contain exactly the same elements, and are 
1Morph. Jal, VII. 726. 
ae 
