124 
a much greater proportion of secretion than the lower epithelium 
on the ventral side. The kind of giand cells that particularly gives 
the epithelium its characteristic appearance has a siender shape 
and contains an acidophilous secretion. It consists of clots of irregular 
shapes. Stained with Ehrlich’s hematoxylin -j- eosin, this secretion 
assumes a peculiar dark dirty-red colour. The dark shade in the 
stained sections is due to the secretion’s own colour which causes 
the earlier mentioned brown colour of the animal’s body. I have 
previously pointed out how the dorsal epithelium in the case of 
Meixneria abounds with masses of giand cells that contain a black- 
brown secretion with large irregular-shaped clots (Bock 1913). In 
Cryptophallus we have a distinctly related type of giand, but the 
secretory clots are here much smaller. The giand cells are entirely 
filled with them. As a result of the immense number of giand 
cells, the production of this secretion must be enormous. At the 
same time the scarcity of rhabditi in the epithelium rather surprises one. 
Under such conditions it seems likely to attribute a function similar 
to that of the rhabditi to the mentioned secretion, which would 
then have brought about a reduction in the quantity of rhabditi. 
It seems, as it were, as if the production of rhabditi were disap- 
pearing and thus only rudimentary. The cells carrying rhabditi are 
indeed so few that one must directly search for them. The rhabditi 
are only 6 p long and up to 2 p thick, and are more rod-than spindle- 
shaped, with rounded ends. Stained as above, they assume a clear, 
lustrous scarlet colour. Arranged in bundles, they occur exclusively 
in the outer quarter of the dorsal epithelium. On the ventral side 
with its lower epithelium, they are found in its outer half. They 
are here even more scarce than dorsally. The mucous cells are, 
on the other hånd, less frequent on the dorsal than on the ventral 
side and do not occur in any great number. Efferent ductuli from 
the giand cells located in the sub-epithelium are, furthermore, found 
in the epithelium, and these carry a pronounced cyanophil secretion. 
The short and finely ciliated supporting cells of the epidermis have 
as usual a disc spread out toward the free surface; the compressed 
outer parts of the giand cells are located between these cells. 
Fibres that are very well stained with hematoxylin are distinguished 
in the basal fourth of the epithelium. The basement membrane is 
on the outside studded with these delicate rods, not much thicker 
than the cilia. 
