12 FRANCIS H. WELCH. 
The uterus (fig. 1,, fig. 2, 4) is a fibrous canal! occu- 
pying the centre of the segment from above downwards for 
two thirds of the distance, not approximating so closely the 
lower boundary of the segment as the upper, and slightly 
bulbous at each end, especially the lower where it is joined 
by the vagina. Up to the adult period of the segment it is 
zig-zag from above downwards, as seen in a longitudinal 
section, though, as seen in a vertical section (fig. 3, g), it 
does not deviate towards the front or back boundary of the 
visceral space; in a mature segment it is straight in either 
view. In shape it is oval, flattened from side to side, ~4; in. 
transversely by +; in. from before backwards (fig. 1, A) ; it 
is composed of fibrous tissue with an epithelial lining. 
Slightly from the upper, but markedly from the lower 
extremity, the ovarian channels radiate from it, but on each 
side they join it more or less horizontally. These ovarian 
channels (fig. 2, m), or smaller offshoots from the central 
canal, have essentially the same structure as the uterus; their 
length and direction varies with the position of the glands to 
the central canal. From the sides of the uterus the ducts are 
symmetrical, in number on each side amounting to about 
twenty-two; not uncommonly they are bifurcated and 
occasionally branched to three or four degrees. Equally 
with the prolongation of the uterine structure into the nar- 
row communicating channels, so in reference to the limiting 
membrane of the ovarian glands, there is an irregular bulbous 
expansion retaining the gland structure or vitelline masses 
which lie in excavations in the granular albuminoid substance 
within the visceral space. 
The shape of the ovarian glands varies with position, in 
number they amount to about forty-four in each lateral half 
of the segment, and in size from 3; in. by +5 to +5 by +25. 
Those placed between the upper and lower end of the uterus 
and the boundary between one segment and another are ex- 
1 According to the Sydenham translation of Kuchenmeister’s ‘ Manual,’ 
Qnd edition, the name designating this parasite was given it by Kuchen- 
meister consequent on the asserted character of the median uterus as “a 
continuous tube around which the sides of the worm enfold themselves. 
This tube, which appears to be continuous, and which I regard as a canal, 
induced me to call the species 7. mediocanellata”’ (p. 138). In this brief 
description one would be led to infer that the uterus is continuous 
throughout the parasite, not special to each segment. If we compare the 
canal of this worm (fig. 2, 4) with the sketch of the 7. sodium (Cobbold’s 
‘ Entozoa,’ p. 213; Aitken’s ‘ Prin. and Practice of Medicine,’ 6th edition, 
p. 162), taken from Rokitansky, we shall note that the divergent characters 
of the two are very slight. Even on many other points there is a close 
approximation in anatomy between the two species, the main distinction 
being centred in the head. 
