274, T, R, LEWIS, 
takes place at the other end of the alimentary canal. The 
course and texture of the cesophagus and intestinal canal are 
the same as in the male, and do not differ from such struc- 
tures in the Milaride generally. 
The vagina (fig. 1 6) terminates about 4th of an inch 
below the oral extremity, generally a little above the junc- 
tion of the esophagus with the intestine, as represented in 
the plate. Itis a well-developed muscular tube, composed 
of longitudinal and transverse fibres, and the channel is 
occupied by a row of ova lying two or three abreast. It is 
about }th of an inch in length, is curved upon itself about 
the middle, and divides into the two uterine tubes delineated 
in the figure (14). These tubes are also filled with ova, 
each ovum containing a more or less clearly differentiated 
embryo, especially towards the vaginal end; but in no part 
of the genital tract are free embryos to be found. On tracing 
the course of the uterine tubes by means of a low power 
until within about a quarter or half an inch of the caudal ex- 
tremity (fig. 1c), they are found to terminate in still smaller 
tubules (the ovarian); and these, after forming numerous 
coils around and alongside the intestinal tube, terminate 
abruptly in a cecal manner, retaining pretty much the same 
diameter throughout their entire course. 
The caudal extremity (fig. 1c) of the female is not so 
complicated as that of the male ; it is very slightly pointed, 
and at its extremity something suggestive of the remnant of 
a gland, or of the site of eat of the water-vascular system, 
may frequently be discerned: in the male also a similar 
appearance may often be detected. 
The ova in the earlier stages are oval, but as the develop- 
ment of the contained embryo advances, the firm though 
thin ‘‘ shell”? becomes more elongated and the ends of the 
ovum more blunt. The ova are about ~1,th of an inch in 
length and about +,5,th in width. When a ripe ovum is 
crushed beneath the covering glass a well-developed embryo 
escapes, which, however, does not manifest any activity. 
The embryos when thus deprived of their covering vary 
somewhat in size, the average dimensions, of the particular ~ 
specimens measured, were found to be about ,{,th of an 
inch from end to end and about ;,5;th at the widest part— 
just jth as broad as long. With reference to these embryos 
it may be further remarked that the thickish, yellowish fluid 
in which the mature worms are imbedded may be squeezed 
through the orifice in the tumour (usually found without 
difficulty) communicating either with the aorta or the ceso- 
phagus, according to its anatomical relations. In this way 
