27 
part of the seg'ment, while the female organs are more ventral in 
position. 
Male organs. — Three testes (fig's. 24:, 32, 33) are present, the usual 
number in worms of this genus. The}^ are situated near the dorsal 
surface, in the posterior portion of the proglottis. When at the 
height of their development, in the ^munger segments, they occupy 
the greater part of the central portion of the parenchyma. Normally 
. two are on the right and one on the left of the median line. This 
position may be reversed, or rarely only two or as man}^ as four or 
five may be present, as occurs also in Hymenolepis diminuta (p. 89). 
Yasa efferentia from the three testes unite to form a vas deferens 
which enters the base of the cirrus pouch. The vas deferens just 
before reaching the latter is often dilated to form a small seminal 
reservoir (Blanchard, 1891a), as I have also noticed frequently in speci- 
mens both from man and from the rat. 
The cirrus gwucli (figs. 22-21, 26-28, 31, c. ^9., figs. 32, 33) is a 
club-shaped organ with muscular walls situated near the anterior 
border of the segment, with its long axis directed transversely, or 
often somewhat obliquely backward (caudad) toward the genital 
pore. It lies on the dorsal side of the longitudinal nerve and the 
excretor}^ canals (figs. 32, 33). Within the cirrus pouch the vas 
deferens dilates to form a seminal vesicle^ and then narrows again to 
form a very slender tube which may be protruded through the genital 
pore (Leuckart, 1863), or, perhaps, as is common in tapeworms, and as 
occurs in Hymenolepis diminuta (p. 89), protracted into the vagina of 
the same segment. 
Female organs. — The vagina (figs. 32, 33) lies on the ventral side of 
the cirrus pouch, between it and the excretory vessels and longi- 
tudinal nerve. It is at first narrow, but mediad from the base of the 
cirrus pouch, it is swollen into a large oblong' seminal receptacle (figs. 
22-21, 27-33), usually filled in adult segments Avith a highlv refractive 
hair-like mass of spermatozoa, and for this reason A'eiy apparent and 
prominent. It is easily recognized in any mature segment eA^en under 
loAv magnification, lying near the anterior border of the segment, and 
extending iiiAvard toward the median line a A^ariable distance in differ- 
ent segments. 
Posterior of the seminal receptacle lies the ovary (fig. 21, 6>^^, figs. 
32, 33) elongated transA^ersely and bilobed. The egg cells in the ovaiy 
measure 10 to 15 y. 
The yolk gland (fig. 21, y. g.^ figs. 32, 33) is an OAmid bodA' situated 
in the median line, toward the A^entral surface of the segment and 
posterior of the OA^ary in the space between the backward prolonga- 
tions of its right and left lobes. The cells of the yolk gland are 
small, 2 to 1 yw in diameter, strongly eosinophilic. 
