564 
DR. NELSON ON THE REPRODUCTION OF THE ASCARIS MYSTAX. 
The posterior extremity of the female becomes suddenly narrowed to a blunt point 
(fig. 4 n), a short distance from which is the anal aperture. 
The tail of the male, as I have said, is abruptly curved on itself (fig. 3 a), so that 
its dorsum is convex (fig. 5 a) and its ventral aspect concave (fig. 5 h). A short 
distance from the conical apex and on the ventral surface (fig. 2 b) is the anus (figs. 2 
and 5 c), and a little in front of this is the genital orifice (figs. 2 and 5 d). 
On either side of the concave surface (fig. 2 h) in the male is a projecting ridge 
(fig. 2 f), consisting of a number of conical tubercles placed in a row and supporting 
a horny membrane that stretches between them. This membrane is finely serrated ; 
the teeth look towards the tail, and no doubt serve an important part in giving it a 
secure hold while embracing the body of the female. 
The intestinal canal is a straight tube (figs. 1 c and 5 i) passing from the mouth to 
the anus, situated in the axis of the body and surrounded by loose cellular tissue. It 
usually contains undigested particles and portions of intestinal villi of the Cat. 
After this general description, I pass to the consideration of the reproductive 
organs, and commence with the generative apparatus of the male as being the more 
simple. 
By squeezing the tail carefully between plates of glass two spicula (fig. 2^) are 
forced out of the genital orifice (fig. 2 d), already mentioned. These spicula are 
slightly curved, the curvature looking towards the body, and in the ordinary state of 
the parts are entirely retracted within the trunk. They are placed one before the 
other, they are about -g^th of an inch in length and j^^dth in breadth ; their con- 
sistence is horny, their structure tubular with a joint at the base (fig. Qf), which 
allows of the spiculum being withdrawn (fig. 5 g). That part beyond the joint 
(fig. 6 c, y) which always remains within the body even when the spiculum is pro- 
truded, is cartilaginous in appearance, and is furnished with tooth-like projections for 
the attachment of the muscles engaged in its protrusion and retraction, fig. 6 d. 
Near the apex is an aperture (fig. 7^) by which the seminal fluid escapes, when forced 
along the tubular spiculum (figs. 6 and 7 «)• 
Of the way in whieh copulation takes place 1 can speak with certainty, having in 
my possession a specimen in which the tail of the male is wound round so as to em- 
brace that portion of the trunk of the female where the orifice of the vagina (Plate XXX. 
fig. 91 a) is situated, by which means the spicula are directed into its cavity. 
The internal organs of generation in the male consist of a single tube variously con- 
tracted and dilated, but without any branching or division (Plate XXV*. fig. 5 h,h, 
m, w, o). This tube is placed between the integument and the intestinal canal 
(fig. 5 i) and originates in a very fine caecal extremity (fig. 5o). As it gradually 
enlarges it becomes much contorted, doubled backwards and forwards, surrounding 
the intestinal canal and occupying the posterior half of the body. 
Commencing at the narrow extremity (fig. bo) is a very long tubular portion 
(fig. 5 o,m) that answers to the testicle ; joined to this is the seminal vesicle (fig. 5 k), 
