ANIMAL PARASITES 



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mesal line, near the lower portion of the proglottis, the vagina 

 bends down to an indistinctly outlined mass, which is the develop- 

 ing ovaries. Passing forward from this is the unbranched 

 uterus. The flocculent mass largely filling the proglottis is made 

 up of the lobes of the testes. 



Mature Proglottides. — Selecting a proglottis somewhat beyond 

 the middle of the strobila, study the mature reproductive system. 

 Compare Fig. 6, illustrating a related genus. 



The more anterior duct passing mesad from the genital pore is 

 the vas deferens. The racemose lobes of the testes are attached 



Fig. 6. — Mature proglottis of a tsenioid tapeworm Ichthyotcenia. c, cirrus; 

 c.p., cirrus pouch; g.p., genital pore; i, vas deferens; m.g., Mehlis gland; o, ovary; 

 r.s., receptaculum seminis; t, testicle; u, uterus; v, vagina; v.d., vitelline 

 duct; u. fir., vitelline gland; v. v., ventral excretory vessel. (After Fuhrmann.) 



to the vas deferens by very delicate efferent ducts. They occupy 

 what is generally interpreted as the dorsal surface of the segment. 

 At its outer extremity the vas deferens enters the swollen cirrus 

 pouch, within which it terminates in the cirrus or penis. 



Running parallel and caudad to the vas deferens is the vagina. 

 Towards the middle of the proglottis the vagina bends caudad and 

 unites with the oviduct passing from the paired ovaries. Near its 

 point of union the vagina enlarges slightly to form a receptaculum 

 seminis. The ovaries, lying to either side of the mesal line, are 

 of unequal size and are composed of a number of tubular follicles. 

 In the middle line just back of the ducts from the ovaries is the 

 rounded Mehlis gland, or so-called shell gland. Close to the 

 caudal margin of the proglottis is the yolk, or vitelline gland. The 



