=< ° 
* 
as 
. - 
404 PROCEEDINGS OF THE CANADIAN INSTITUTE. 
and is provided with the usual pore canals. Outside of the cell 
walls, and of a diameter equal to that of the cell, are sometimes in 
hardened sections small masses which show a striation parallel to 
the pore canals. These are probably in all cases due to a destruction 
of the excessively fine cilia which has been described by Thanhoffer’ 
in the frog, and by Edinger’? in the eel, pike, carp, &c., and observed 
by myself in scrapings from the intestine of the living fish. I have 
never succeeded in observing their movement. Edinger suggests 
that they are in constant action during digestion. It is impossible 
to verify this with certainty, as removal of the cell apparently causes. 
instantaneous death. In this respect, as in their extraordinary 
delicacy, they are comparable to the cilia of the cylinder cells mingled 
with the olfactory cells of the nasal cavity of higher vertebrates. 
The beaker cells are quite different from those of the cesophagus, 
and this difference corresponds to that between the ordinary cylinder 
cells of the midgut and the esophagus. . In both cases the beaker 
cells are not original structures, but are metamorphosed products of 
cylinder cells. I might mention here that I observed in fresh ciliated 
epithelium from the spiral valve of the sturgeon, several cases of 
beaker cells still possessing a fringe of cilia. On the other hand the 
effects of the drug pilocarpin teaches quite clearly the origin of the 
beaker cells. After the peristaltic contractions caused by this drug 
have passed away, beaker cells are found to be totally absent from 
the surface of the intestine and Lieberktihnian crypts, their place 
being occupied by cylinder cells. A fresh supply is obtained in the 
resting intestine, and these can only come from the cylinder cells, 
The theca of the beaker cell presents various shapes and sizes. 
graded from the cylinder cell. Sometimes a short portion of the 
wall is swollen to form the theca ; the peripheral wall is lost and the 
contents become very coarsely granular, the remainder of the con- 
tents of the cell being unchanged. Further progress shows the 
advance of the transformation nearer the nucleus, which, however, 
it does not embrace; at the same time the theca loses its swollen 
character and becomes elongated. The opening may be as wide 
or wider than the original cell, and through it frequently projects. 
a rounded mass of the swollen contents. 
The crypts of mucous surface are simply those of the pylorus in 
1 Pliiger’s Archiv, Bd. VIII., p. 391. 2 Loe. cit. 
