91 
Fig. 89. — Proglottids of H. diminuta from pos- 
terior portion of strobila. Enlarged. (After 
E. Parona, 188-J. fig. 7.) 
tube from the seminal receptacle, then turns toward the ventral 
surface and backward, and in the midst of the complex of cells, known 
as the shell gland, is joined bv the duct from the yolk gland. The 
s/iell gland (.y. r/.. tigs. SO, 81) is a little rounded mass which lies between 
the right and left lobes of the ovary. The yolJc gland iy. ^.. hgs. 76. 
80-82) is lenticular in shape and situated on the ventral side of the 
shell gland and somewhat more pos- 
teriorly. With respect to the main 
bod}' of the ovary the yolk and shell 
glands are posterior (caudad). 
From its point of union in the 
shell gland with the volk duct the 
oviduct turns forward and empties 
into the vterus on the dorsal side 
of the anterior part of the ovary 
(tigs. 80. 81). The uterus at first is 
simply a transversely elongated mass 
of cells without a cavity, but as it 
develops becomes hollowed out and 
the tube thus formed grows in various directions, sending out diver- 
ticula and increasing in size generally so as to gradually fill up prac- 
tically the entire proglottis. After the uterus begins to grow actWely 
the ovary quickly disappears. The yoke gland, however, remains 
apparent for a long time. According to the degree of development 
which the uterus, has reached it is evident that the appearances will be 
somewhat diflerent. Zschokke (1889). for example, has described a 
condition (fig. 84) in which 
the uterus has the form 
of two transverse canals 
uniting at one side so as 
© 
to form a loop, the two 
limbs of which are also 
connected at various other 
points. Grassi (18881) no- 
ticed in sections of seg- 
ments in which the uterus 
had not reached its final 
development, that it ap- 
peared as a large number of cavities of various sizes communicating 
with one another (figs. 82, 83). 
As the uterus grows the diverticula become crowded together, and 
the eggs form a more or less compact mass occupying nearly the whole 
segment. The adult uterus, at first sight apparently a simple sac filled 
with eggs, is thus seen to be more complex; its cavity, although contin- 
uous, is broken up by incomplete partitions, and by innumerable pro- 
Fig. 90. — Proglottis of H. diminuta containing fully developed 
ova, rendered transparent Avith potash. Enlarged. (After 
Grassi. 18881. pi. 11. fig. 15.) 
