F. J. Meggitt 
303 
The excretory system consists of the usual four longitudinal vessels, two 
dorsal and two ventral. The former are exceedingly minute and are external 
to the two latter. At the posterior limit of each proglottis, the two ventral 
vessels communicate by a large transverse commissure. No such commissure 
could be found between the two dorsal, probably on account of their small 
size. In segments filled with mature eggs, both dorsal and ventral vessels 
disappear. In the anterior segments they are of equal size. In the scolex they 
run between the suckers in a wavy course, giving off numerous anastomosing 
branches and opening into a circular commissure, immediately posterior to 
the rostellum. 
There are two complete sets of genital organs in each proglottis (PL XVII, 
fig. 10). The genital pore is half way along each lateral margin or else slightly 
anterior. A very shallow genital cloaca is present. The genital canals run 
dorsal to both excretory vessels and to the nerve. 
The cirrus-pouch is long and slender and devoid of special retractor 
muscles. It only extends as far as the nerve, not past it as Fuhrmann (1909, 
p. 120) states, “Der Cirrusbeutel ist langgestreckt (0-3 mm.) und geht iiber 
den Langsnerv bis zu dem nach aussen vom ventralen Exkretionsstamm 
gelegenendorsalen Exkretionsgefass,” and is straight. The cirrus is armed 
with fine spines and has a small terminal enlargement. It runs in a straight 
line half-way along the cirrus-pouch and then merges into the vas deferens; 
after this point the cirrus-pouch is less muscular. The vas deferens is twice 
the diameter of the cirrus and is uncoiled while still within the pouch. On 
emerging, it coils into a loose ball and then, running posteriorly, breaks up into 
the vasa efferentia. There is no vesicula seminalis, the coils of the vas deferens 
functioning instead. The testes (t.) form a broad band across the proglottis, 
are approximately 100 in number and are posterior to the female glands. 
None are to be found in the anterior half of the segment. They surround 
dorsally and laterally, but not ventrally, the longitudinal excretory canal and 
extend as far as the longitudinal nerve. Dorso-ventrally they form an indis¬ 
tinct double layer in the centre of the proglottis, being three deep at the 
extremities and only one deep in the centre. 
The vagina (v.) opens posteriorly to the cirrus and runs slightly posteriorly 
to open into a spindle-shaped receptaculum seminis ( r.s .) situated just in¬ 
ternally to the excretory vessels. The ducts from the receptaculum seminis 
take their usual course. The ovary (ov.) is crescent shaped with the con¬ 
cavity directed posteriorly and internally, and with the convex side deeply 
lobed. The yolk-gland ( y.g .) is a shapeless irregularly lobed gland lying 
posteriorly and internally to the ovary. Both ovary and yolk-gland lie im¬ 
mediately internally to the longitudinal excretory vessels with the ovary 
half-way between the posterior and anterior borders of the segment. The 
shell-gland is very compact, non-lobed, and lies on the dorsal surface between 
the ovary and yolk-gland. A definite uterus is not developed. The oviduct, 
after passing through the shell-gland, persists for an exceedingly short distance 
Parasitology xii 
20 
