360 BENEDICT. [Vol. XVI . 



A loose sheet of circular muscle fibers weaves around the 

 longitudinal bundles. Large fibers pass in a transverse direc- 

 tion between these muscle sheets. The divisions between the 

 proglottids are formed by the interlacing of these fibers with 

 similar ones which cross them at right angles, both sets being 

 here much more complicated than in other regions. 



In the scolex the longitudinal muscles are represented by- 

 scattered fibers, not arranged in compact bundles, passing ante- 

 riorly between the suckers, a few extending to the anterior part 

 of the scolex. Other fibers, arranged in a radial direction, ex- 

 tend between the suckers, and are connected with the muscula- 

 ture of these organs. 



Sexual Organs. — A common genital sinus is present, situated 

 a little anterior to the middle of the margin of the proglottis. 

 Its position is irregularly alternate in the chain of proglottids. 



Male Organs. — The testes are from thirty-five to fifty in 

 number, and about .05 mm. in diameter. They are scattered 

 throughout the space between the longitudinal muscles and the 

 vitellaria. Each testis is closely invested by the tunica propria. 

 Minute ducts collect the spermatozoa and join together, making 

 larger ducts near the center of the proglottis. These larger 

 ducts unite to form a dilated thin-walled vas deferens .02 mm. 

 in diameter, which forms a convoluted mass of coils in the 

 middle of the proglottis (PI. XVI, Fig. 27, v d.). The wall of 

 the vas deferens consists of the tunica propria and an epithe- 

 lial covering, while the coils are closely bound together by 

 parenchymal strands. The vas deferens is always distended 

 with spermatozoa. 



The distal end of the duct passes upward to the dorsal muscle 

 bundles, and there enters the cirrus sac. At a distance of 

 .10 mm. from its entrance to the cirrus it undergoes a sudden 

 diminution in size and receives a delicate muscular coat as well 

 as an epithelial lining. At the point where the vas deferens 

 enters the cirrus sac it Is only .015 mm. in diameter, with 

 walls .005 mm. thick, the greater part of which is a muscular 

 coat. The duct bends sharply as it enters the cirrus pouch. 



The cirrus sac is an elongated oval in shape, slightly con- 

 stricted in the middle. It extends from the edges of the geni- 



