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ILLINOIS BIOLOGICAL MONOGRAPHS 



[364 



diameter of the vas deferens and extends forward and mediad in front 

 of the receptaculum. The testes are usually confined entirely to the 

 side opposite the pore but two or three may lie on the pore side of the 

 median line ; however they do not reach as far as the median line of 

 the vitelline gland. Likewise, the testes are nearly all in the distal 

 half of the proglottid. In both these features is seen a superficial 

 resemblance to Anoplocephala. The testes extend well across the ventral 

 excretory duct laterally. When not disturbed by the ventral excretory 

 duct they extend entirely thru the medullary portion. 



The vagina lies ventral of the cirrus pouch. Laterad of the excre- 

 tory ducts its walls are glandular. Very early, long before sexual 

 maturity, it expands at its inner end forming a receptaculum seminis. 

 This cavity grows and extends laterad until it reaches the outer edge 

 of the dorsal excretory duct. It is largest at its inner end and its 

 diameter decreases gradually laterad so that it merges imperceptibly 

 into the unenlarged portion of the vagina. The ovary is formed of about 

 15 lobes which radiate anteriorly, distally, and laterally; the female 

 glands are situated slightly to the pore side of the median line. The 

 vitelline gland is of rather unusual shape, owing to the size of the 

 median lobe and its encroachment on the space within the circle of the 

 gland. 



The uterus is a very simple reticulum with its different branches 

 wide apart and clearly distinct from each other. It lies anterior to the 

 ovary and extends laterad to beyond the excretory ducts on either side. 

 In front of the ovary two or three transverse tubes are to be found ; in 

 the lateral regions, six or eight. The lateral development of the pro- 

 glottids is very peculiar, and apparently abnormal, in that the ova do 

 not pass into the uterus. In one specimen, having in all 278 proglot- 

 tids, the uterus had already begun to develop in the earliest proglottid 

 sectioned, number 148. In proglottid number 186 the receptaculum 

 had reached its full development and was filled with sperms. In suc- 

 ceeding proglottids it was fully developed but nearly always empty. 

 Proglottid number 187 showed all evidences of sexual maturity. The 

 vesicula and receptaculum are developed, and the branches of the 

 netlike uterus have become open tubes. In the following 91 proglottids 

 however only 11 uteri contain eggs, these being between the 222d and 

 240th proglottids. The uterus is distinguishable in all except the most 

 posterior, attenuated proglottids ; it never develops beyond the reticular 

 stage. In proglottid number 260 the degeneration of the ovary is nearly 

 complete. The other two cestodes at hand of this species were cleared 

 and examined in toto. They showed the same condition ; in only an 



