a 
Sere ey 
ye ee ee ee ee 
ALIMENTARY CANAL, ETC., OF AMIURUS CATUS. 395 
ous with that bounding the remainder of the cell; this was clear 
enough evidence of the possession of a cell-membrane. Again, seve- 
ral other forms or variations of structure were observed in a few 
cases, and these I am in doubt whether to classify as normal or patho- 
logical. They were obtained by maceration in Miiller’s fluid, and in 
them the finely granular material of the neck and cap of the cell was 
aggregated into clumps, with clear spaces between them ; in the cen- 
tre of each of these clumps a round body, much smaller than the 
nuclear body proper, was observed. The nuclear bodies themselves 
retained their usual appearance. Sometimes an optical section of the 
cell instead of showing clumps yet revealed their round central bodies 
as regularly disposed as those of the clumps. 
Whether these structures are secretory or nervous in function it is 
impossible to say. From the constant presence of the clear glassy 
fluid, and its disposition at the head of the cell, one would be in- 
clined to the former view. 
As already mentioned, the description of the mucous membrane of 
the mouth applies equally to that of the pharynx. The slime cells, 
however, increase in number, and just behind the teeth-pads they 
become aggregated together into patches, one above and one below. 
At the commencement of the cesophagus they dwindle away, and 
before the posterior moiety of the csophagus is reached have com- 
pletely vanished. 
The clavate cells are distributed equally throughout mouth and 
pharynx. 
A tranverse set of striated muscle fibres connect the two hypo- 
pharyngeal bones. Behind them it gradually surrounds the pharynx, 
and immediately before the cesophagus is reached it formsa thick 
muscular layer. At this point is the origin of the muscle fibres 
forming the inner longitudinal layer of the cesophagus. 
CSOPHAGUS. 
The low epithelium of the pharynx passes into that of the wsopha- 
gus, with a gradual increase in the height of the constituent cells. 
The muscularis mucose is represented by but a few fibres, while 
the submucosa is thin and shows no distinction from the tissue 
sheathing the longitudinal muscle bundles. These latter are widely 
separated and coarsely grouped, and, although first appearing an- 
28 
