504 
PAUL PELSENEEE. 
Between this epithelium and the prismatic muscular cells we 
see absolutely no connective tissue. On the upper side of 
the disc, outside the sphincter, the epithelial lining thickens 
very much, which is explained by the fact that it is by this 
part that the adherence of the sucker to foreign bodies is 
produced. 
I have not remarked the constant presence of the cuticular 
pads (“bourrelets”) which Niemiec described. 1 Perhaps these 
parts are specially visible in suckers of large size. 
Beneath the epithelial thickening of which I speak, we find, 
all around the disc, glandular cells in the form of a flask with 
a very narrow neck. The efferent duct of these cells traverses 
the epithelial thickening and passes out at the upper face of 
the exterior ring of the sucker, that is to say, on the point 
where the adherence is produced. The secretion of these cells 
probably makes this adherence more perfect. 
On the lower face of the sucker the epithelium is less flat- 
tened than on the upper face, and it is united to the prismatic 
muscular cells by connective tissue. 
The peduncle is covered with an epithelium continuous with 
that of the upper face of the sucker, and quite analogous to it. 
The peduncle itself is formed by the continuation of the longi- 
tudinal muscular fibres of the buccal appendage. These fibres 
turn to the lower part of the acetabular disc. 
According to Niemiec, some fibres of the peduncle go to the 
side of the sucker. Such fibres I have not observed. In my 
opinion the longitudinal muscular fibres of the peduncle (fig. 
23, a) only go to the central part of the disc, and are inserted 
on it, between two prismatic muscular cells, by their extremity, 
which ends in a point ( b ). A retracting muscle inserted on 
the side of the sucker would be far from having a useful 
effect. Since it is at this point that the adherence is pro- 
duced, the action of such muscles could only tend to combat 
it, while the muscles inserted on tbe centre of the sucker, by 
removing this point from the body to which the circumference 
1 Loc. cit., pi. iii, fig. 2, c. 
