The adult organisation of Paragordius varius. 443 
which have just left the body of their last hosts, and which have not 
been fertilized, as well as those in the terminal host but of mature 
structure, the ovaries (Ov Fig. 66, Pl. 41) are so densely distended 
with ova that the lateral body cavities are obliterated, the uteri (Ut) 
are empty and appear as narrow slits, and the receptaculum (Rec) is 
folded. In individuals which have been fertilized and which are in 
process of discharging their eggs, the uteri (Ut Fig. 64, Pl. 40) are 
‘distended with ova which have passed into them from the now smaller 
ovaries (Ov), ova are found in the oviducts (Ow Fig. 68, Pl. 41) and 
the atrium (Air Fig. 75, Pl. 41) and cloaca (in the latter, O Fig. 72, 
agglutinated into a long string), and the receptaculum (Rec Fig. 68, 
Pl. 41) is filled with spermatozoa (Sp), spermatozoa being also found 
in the atrium and the cloaca. Finally when the egg string has been 
nearly wholly deposited outside of the body, the ovaries are collapsed 
sacks (Ov Fig. 63, Pl. 40) so that the lateral body cavities (L. Cav) 
appear very clearly, a few ova (O) remain in the uteri (U?) and ovi- 
ducts, and the atrium and cloaca are filled with that portion of the 
egg string which has not yet been deposited. When all the eggs have 
been deposited, the whole body is more or less collapsed, ribbon- 
shaped instead of cylindrical, being greatly flattened dorso-ventrally. 
One individual kept in an aquarium until all the eggs had been 
discharged, died at the end of this process. And in view of the facts 
that the oviposition induces very considerable rending and tearing of 
the internal organs, especially the perienteric membranes and the 
mesenteries, and that at no points upon the germinal epithelium are 
to be found any growth centres of a new generation of ova, it is 
probable that completed oviposition means death for the individual. 
These worms lay their eggs even when not fertilized, as I conclude 
from an individual kept in an aquarium, the deposited ova of which 
underwent no cleavage (and in this case they were not laid in con- 
nected string, the usual manner, but in disconnected masses). 
The ovaries. These are epithelial sacks closed at all points 
except medially where they open into the uteri. When filled with ova 
and before the commencement of oviposition, each may be likened in 
form to a half disc (Ov Fig. 66, Pl. 41), flattened before and behind 
by the pressure of others in front and behind, curved on that sur- 
face next the concavity of the hypodermis, straight on the median 
surface next the mesentery (Mes). At this stage the ovary is distended 
with ova, and completely fills the lateral body cavity. The epithelial 
lining is often very difficult to see clearly at this stage, since by the 
