Flexure of the testis is common in the Phasmidia 

 {Rliahditis, Fig. 124 A) but just how widespread the 

 phenomenon is we do not l<now. In Heferodcia marioni 

 the one or two testes may be either flexed or outstretched. 

 In the Aphasmidia, flexure is unknown except in some 

 of the forms with a single testis. 



The same differentiation of groups according to origin 

 of germ cells is seen in the male as in the female (p. 135) ; 

 hologonic forms (Dioctophijmatoidea and Trichuroidea) 

 have an extended region of germ cell formation while in 

 the remaining nemic groups germ cell formation is con- 

 fined to the end of the testis. 



H 



K 



M 



N 



Fig. 124. 



Diagrams of male reproductive system. The epithelial portions 

 are white, the germinal portions black. When rectal (i. e. cloacal) 

 glands are known to be attached to the ejaculatory duct (A, C. D) 

 they are shown as lateral protuberances, A — Rhabditis strongyloides. 

 B — Oewphagostoinum dentatuin. C — Rhabditis hnnbdiensis. D — Spir- 

 ououra affiiie. E — Rliiffoneiiia infectuin. F — Heterodera tnarioni 

 (with two testes). G — Heliconema anrfuillae. H — Cucullanus hetero- 

 chrotis. I — CfuaaJlanus lacustris. J — Heterakis gallinae, K — Trichuris 

 suis. L — AiiticOhta typica. M — Aganiennis decaudata. N — Enoplus 

 C07nmunis, O — Desviolaimus zeelandicus, P — Metoncholaimus pris- 



tiurus. Q — Anaplectus granulosus. R — Trilobus gracilis. S — Cliroma- 

 dora quailriUnea. T — Halichoanolaimus robustiis {Spllophorella 

 parndoxa and Metachroiiiadora onyxoides are similar). U — Saba- 

 tieria hilaruln. G, After Yamaguti, 1935, Jap. J. Zool. v. 6 (2). 

 H & 1, alter Toernquist, 1931, Goeteborgs Kungl. Vetenskaps. o. 

 Vitterhets-Samm. Handl. s. B. v. 2 (3). K, after Rauther, 1918, 

 Zool. Jahrb. Abt. Anat. v. 40. L, after Cobb. 1890. Proc. Linn. 

 Soc. N. S. Wales, s. 2, v. 5. M, after Steiner, 1923. J. Heredity. 

 V. 14 (4). Remainder original. 



151 



