1048 DR. F, E. BEDDARD ON 
the small receptaculum passes posteriorly into a duct leading to 
the internal portion of the female apparatus. It seems to me 
to be impossible not to recognise in this tube a rudimentary 
vagina; but the dilatation can hardly be compared to a recep- 
taculum, since that exists elsewhere. 
In the first few proglottids of the worm, the female efferent 
apparatus is still more highly developed than in those proglottids 
which have just been considered. I find, in fact, in the first six 
or so of those proglottids in which the reproductive apparatus 
generally is recognisable in its details, that the vagina (text-fig. 5) 
Text-figure 5., 
Moncecocestus ercthizontis. 
Part of a horizontal section through an anterior proglottid where the 
vagina (v.) has not commenced to disappear. 
g-c. Genital cloaca. 
is a wide thick-walled tube which opens on to the exterior close 
to, and in front of, the cirrus-sac on the cne hand, and communi- 
cates with the receptaculum seminis on the other, thus forming a 
continuous female efferent apparatus, like that of more normal 
Cestodes. It is, perhaps, during this transient state that fertili- 
zation is effected, also in the normal way vid this tube and not 
through the interstices of the body parenchyma. I have noted 
certain stages in the degeneration of the vagina; that part of it 
which opens into the receptaculum seminis persists, after it has 
