MORPHOLOGY OF CESTODES FROM POULTRY 35 



shaped. Genital pores usually unilateral, situated one in each 

 segment, at or in front of middle of lateral margin, frequently 

 marked off by papilla. Male and female canals pass on dorsal 

 side of nerve and excretory vessels. 



Male Reproductive Organs: Testes 20 to 30 in median field 

 surrounding female organs, most of them lying on aporose side 

 of latter. Vas deferens situated in anterior third of segment, 

 beginning near median line, and extending in much convoluted 

 course laterally to base of cirrus pouch which it enters and, after 

 a few coils in basal portion of latter, passes into cirrus. Cirrus 

 pouch pyriform, 75 to 100/;t in length. Basal portion surrounded 

 by prominent layer of longitudinal muscle fibers, neck with thick 

 layer of transverse fibers. Cirrus without apparent spines. 



Female Reproductive Organs: Ovary in middle of segment. 

 Yolk gland posterior to ovary, irregularly reniform, slightly longer 

 in its transverse axis, about lOO/x in diameter. Shell gland promi- 

 nent, 50/i, in diameter, immediately in front of yolk gland. Vagina 

 begins at genital pore, posterior to opening of cirrus pouch, at 

 first very slender but at distance of 15 to 25/* from genital pore 

 swells out into thick-walled tube, functioning as seminal recep- 

 tacle. This extends transversely across segment and joins oviduct 

 on dorsal side of ovary near median line. Oviduct, after being 

 joined in shell gland by vitelline duct, proceeds forward and ends 

 on dorsal side of ovary. Definite and persistent uterus not devel- 

 oped. Eggs pass from distal end of oviduct, become imbedded 

 in fibrous and granular or gelatinous mass which fills up most of 

 segment. This mass divides into 50 to 100 portions to form egg 

 capsules, each surrounded by membrane and containing 6 to 12 

 or more eggs. Egg is surrounded by three envelopes, — inner, close 

 to onchosphere, often scarcely visible ; middle layer or envelope 

 much folded, giving appearance of network between inner and 

 outer membranes ; and smooth outer envelope. The onchosphere 

 measures 10 to 15/u, in diameter; the outer envelope measures from 

 25 to 50/i in diameter. 



One point noted here that has not been mentioned before by 

 other authors is that the genital pores are irregularly alternate. 



