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ALIMENTARY CANAL, ETC., OF AMIURUS CATUS. 393 
and permits a view of the large oval nucleus placed in the centre of 
the cell. In the lower columnar layers they are of smaller size 
becoming more so towards the base, where one can easily observe 
their differentiation from the surrounding cells. The reticulation is 
at first fine and delicate, but becomes coarser and more marked as 
the cell increases in size and thrust upward. 
These cells have been described in other fishes under the name of 
beaker cells. I have prefered to use the term ‘slimé cells,’ some- 
times employed in referring to them. They do not conduct them- 
selves towards reagents or staining fluids in the same manner as 
beaker cells, from which they differ in shape. In no portion of the 
alimentary tract does the beaker cell show a reticulation in its 
taucigenous portion, nor does it stain generally with Bismarck brown 
or hematoxylon any more deeply than do the surrounding cells. 
The beaker cell again, it is quite probable, is simply a degradation 
of the ordinary surface cylinder cell, while the slime cells show a 
gradual growth and differentiation from those of the deeper epithelial 
layers. The beaker cells and the slime cells must be regarded as 
two distinct kinds of cells producing secretions, which probably’ are 
‘chemically different. 
The other kind of cells referred to as present in the epithelial 
layers of the membrane is known under the names of slime cells, 
club or clavate cells. They are found in the outer skin also more 
highly developed, and of a slightly larger size than in the membrane 
-of the mouth. 
These clavate cells are confined to the deeper epithelial layers 
touching with their rounded heads the layers of flattened epithelium. 
‘They are shaped exactly like a club, the larger ends rather blunt, 
while the neck or handle tapers away into a fine thread-like continua- 
tion, which I have traced to the base of the epithelial stratum. 
(Fig. 1). The structure is provided with a distinct wall, and con- 
tains in it two materially different fluid substances. That filling the 
greater part of the head is strongly light-refracting and contains, 
situated toward the base of the cell, one or more rounded or oval 
bodies provided with radiating strands which have been termed the 
nuclei. They may sometimes be found in the fluid which fills the 
neck of the cells, and are provided with nucleoli. These nuclear 
bodies stain slightly in Bismarck brown, much more so than the sub- 
-stance of the neck which lines the walls of the head for some dis- 
