IV 



VERMES GENITAL ORGANS 



255 



side in front of the anus, generally near the middle of the body. The 

 male genital apparatus (Fig. 168) is a single continuous tube, 

 lying in the body cavity, which falls into several divisions between 

 its blind inner end and its external aperture. The testicle division 



k 



FIG. 168. Ascaris lumbricoides, 

 male genital apparatus, after Vogt 

 and Yung, sf, Lateral lines ; /(, 

 testes ; d, intestine ; sb, sperm vesi- 

 cle ; U, cloaca ; de, ductus ejacula- 

 torius. 



FIG. 1 1 Hi. Ascaris lumbricoides. 

 female genital apparatus, after 

 Vogt and Yung, vo, Female aper- 

 ture ; v, vagina ; sf, lateral lines ; d, 

 intestine ; u, uterus ; o, ovaries ; or, 

 oviducts. 



forms a thin much twisted tube into which a solid axis (rachis) 

 projects from the blind end ; attached to this rachis the sperm cells 

 are found at different stages of development. The germ layer lies at 

 the blind solid end of the testicle tube. The nearer we approach 

 to the efferent duct the more advanced are the stages of develop- 

 ment and ripeness of the spermatozoa. The testicle division passes 

 into a shorter, wider, pouch -shaped division, the sperm vesicle, 



