ALIMENTARY CANAL, ETC., OF AMIURUS CATUS. 401 
tinction of these into parietal and chief cells, such as obtains in 
higher vertebrates, is totally absent in fishes. Nussbaum!’ describes 
two varieties of peptic cells in the pike; one consisting of large 
coarsely granuled cells situated anteriorly and followed by a zone of 
second variety behind, which includes small finely granuled cells. 
Such a distinction in these cells, both as regards structure, relative 
position and size, it may be remembered also exists in the frog. 
Langley and Sewall’ find but one kind of cells in the stomach of 
Gasteropodus trispinatus. 
Cajetan® corroborates Nussbaum’s description of the cells in the 
pike, and also finds a similar distinction in the cells of Cobitis 
barbatula. 
In spite of these discoveries of Nussbaum and Cajetan, which 
are of but doubtful value as regards a functional difference, Edinger’s 
statement, that chief and parietal cells, as such separately, are absent 
in fishes, is still to a great extent true, and it may be regarded as 
established that whatever may be the functions of these cells in 
higher vertebrates, such functions are performed by one kind of cells 
in fishes. In those fishes of which I have studied the stomach 
glands for the sake of comparison with those of Améwris, all, with 
the exception of the sturgeon, showed not the slightest difference 
from the description already given above. I can only compare these 
glands to those of the cesophagus of the frog, as described by 
Langley‘. 
The pyloric mucous surface is like that of the cardia and ceecum 
in the forms of its constituent cells. True glands are absent, what 
is usually called such in fishes, being simply indippings or crypts of 
the membrane, and clothed with long cylinder cells which are not 
different from those of the general surface. They are found up to 
the pyloric valve, where they pass gradually into the crypts of 
the midgut. 1t may be mentioned that as the pylorus is approached, 
the erypts into which the peptic glands open elongate, the glands 
diminish in length, and finally vanish, leaving in their place a much 
elongated crypt. 
The membrana propria of the peptic glands consists of fibres of 
the mucosa closely applied in the form of a sheath, in which are 
1 Archiv fiir Mikr. Anat. Bd. XXI. 2 Journal of Physiol. Vol. II. 
% Zur Lehre von der Anat. und Physiol. des Tract. Intest. der Fische., Bonn, 1883. 
_ 4 The Histology and Physiology of the pepsin-forming glands. Phil. Trans. Vol. 172, Pt. III. 
