Fig. 28. — Hexapoda-Plecoptera : internal male reproductive organs. (A, B, 

 C, and F from Klapalek, 1896; D from Junker, 1923; E from Schoenemund, 

 1912; G from Mertens, 1923; H from Wu, 1923.) 



A, Lcuctra nigra, testes in terminal groups at ends of vasa deferentia, median 

 exit duct very short. B, Pcrlodes (Dictyoptcryx) microccphala, vasa deferentia 

 united anteriorly in arch bearing numerous sperm tubes, connected posteriorly 

 by looped commissure (/). C, Tacnioptcryx trifasciata, sperm tubes in series 

 on united anterior parts of vasa deferentia. D, Pcrla marginata, male larva 12 

 mm long, immature testes with " male ovaries " {MOv) and saclike sperm 

 tubes (ST). E, same, older larva, with numerous egg tubes (ET) on anterior 

 arch of vasa deferentia. F, Capnia nigra, single testis formed by lengthwise 

 union of parts of vasa deferentia bearing sperm tubes. G, Protonemoura praecox, 

 sperm tubes grouped at union of vasa deferentia, the latter discharge directly 

 into long median exit duct. H, Ncnwura vallicularia, vasa deferentia discharge 

 into slender median duct {dct), which opens into large terminal exit duct (Dct). 

 I, Acronenria arida, median genital exit apparatus as seen in undisturbed dis- 

 section. J, same, parts of exit apparatus artificially extended. 



Crpt, phallocrypt; Dct, large median exit duct; dct, small median exit duct; 

 Dcj, ductus ejaculatorius ; Enph, endophallus ; ET, egg tube; g, genital process 

 of tenth sternum (see fig. 29, M) ; GC, genital chamber; k, diverticula of vasa 

 deferentia; I, commissure between vasa deferentia; MOv, "male ovaries"; ST, 

 sperm tube ; Tes. testis ; Vd, vas deferens ; Vsm, vesicula seminalis ; x-x, inner 

 wall of genital chamber. 



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