412 THOS. H. MONTGOMERY jr., 
are numerous in the ganglion; the only transverse nerve fibre com- 
missure is placed close to the anterior end of the ganglion; the 
chromophilic fibres are less numerous than in the nerve cord, some 
of them running longitudinally, others radiating upwards from the 
medio-ventral side of the ganglion. The relation of the nerve fibres 
to the cloacal nerves and to the hypodermis will be described below. 
D. The Cloacal Ganglion of the Male. 
The cloacal ganglion (Cl.G Fig. 80, Pl. 42; Figs. 87, 89, Pl. 43) 
is not so sharply delimited as it is in the female, and represents only 
a slightly enlarged terminal portion of the ventral nerve cord. It 
extends from the point of bifurcation of the tail nerves (Cd. N Fig. 81, 
Pl. 42, just anterior to the vertical portion of the cloaca) behind, to 
the plane where nerves leave its dorsal surface to connect with the 
vasa deferentia in front (Fig. 89, Pl. 43); the length of the ganglion 
varies in different individuals of the same size, from about 107 u to 
180 u. In two males it was higher than wide at its anterior end, 
in another male it was wider than high throughout its course on ac- 
count of the cloaca being pressed down upon it; it is widest and 
lowest posteriorly. Its boundaries are not so clearly marked as in 
the female, since it is not so enlarged, and remains through its entire 
length separated from the cloaca by a parenchym layer. It differs 
from the corresponding ganglion of the female also in containing giant 
nerve cells, in having no chromophobic cells situated in its dorsal half, 
and in that its neural lamella is very low and broad posteriorly. Thus 
in the male the cloacal ganglion is not so sharply differentiated from 
the rest of the ventral nerve cord as in the female. 
From the dorso-lateral angles of its anterior end (Fig. 89) small 
bundles of nerve fibres (Gen. N) pass vertically to the vasa deferentia 
(Vas) placed just above, and near the anterior ends of the latter. On 
each side of the ganglion for a longitudinal extent of about 60 w 
such fibres pass to the vasa; it could not be determinated how these 
nerve fibres terminate in the vasa. These small nerve bundles contain 
some chromophilic fibres but apparently (though this point could not 
be positively determined) they are composed mainly of chromophobic 
fibres. It is possible that some of these fibres may innervate the in- 
testinal wall (Int) which lies between the vasa at this point. The 
fibrous sheaths (Vas. S) of the vasa deferentia are here composed of 
dense, deep-staining concentrically arranged spindle-shaped cells, ap- 
parently a modified parenchym and very similar to that of the sheath 
