STUDIES ON THE DIGENETIC TREMATODES. 405 
so that the outlines of the individual cells are lost. These 
cells certainly do not resemble the large cells (myoblasts) of 
the suckers, the cell-substance being much denser, They 
bear more resemblance to the smaller cells of the suckers, 
but most of all to the circum-cesophageal and vaginal “ gland- 
cells.’ The glandular nature of these latter cells is again a 
matter of hypothesis, and their undoubted resemblance to the 
“ subcutaneous glands” strengthens Bettendorf’s views as to 
their myoblastic nature. The same may be said with regard 
to the cells surrounding the terminal portion of the ductus 
ejaculatorius in the cirrus pouch. All these cells are easily 
differentiated from cells of which the glandular function 
is well established, i.e. prostate gland and shell gland, even 
by ordinary staining methods. 
True cutaneous glands, however, do exist in this species, 
but they are restricted in extent. They occur in the 
anterior part of the body only, situated fairly deeply and 
scattered throughout the region from the pharynx to the 
intestinal bifurcation. Similar cells (cephalic glands) appear 
to exist in many other species, but their occurrence has not 
been universally confirmed. ‘They are not very numerous, 
but their number could not be estimated. Their ducts can 
be easily demonstrated, as also the fact that a considerable 
number of them open around the oral sucker. ‘They are 
somewhat pear-shaped or tear-shaped, with their narrow end 
directed forwards. They measure about ‘036 by ‘019 mm., 
and their contents consist of a homogeneous, finely granular 
material, staining light blue with hemalum-eosin, in the 
midst of which is a large round nucleus, ‘(007 mm. in diameter, 
with distinct nucleolus. The function of these glands is still 
a matter of opinion, According to Leuckhart and Looss their 
secretion exercises an irritative action on the tissues of the 
host, causing an increased flow of juice, and even, according 
to some authors, a flow of blood in certain cases. This seems 
a reasonable enough supposition and is supported by the 
position of the glands. It may also account for the fact that 
some animals, although harbouring an immense number of 
