the rat-flea, ceratophyllus fasciatus bosc. 463 



Plate 28. 



General View of the Reproductive Apparatus of the 

 Male Rat -flea, seen from the Right Side. 



T, T, the two testes ; ep. 1 , the left epididymis in its natural 

 coil ; ep. 2 , the right epididymis forcibly uncoiled ; v.d. 1 , v.d. 2 , the 

 left and right paired vasa deferentia ; v.d. 3 , the common vas 

 deferens; r.l.p., the right lateral prostate gland; r.m.p., the 

 right median prostate ; d.ej., the ductus ejaculatorius ; c.s.o., 

 the " corkscrew-organ " ; d., the urethral duct running spirally 

 round the corkscrew-organ; P, the penis. x 75 linear. 



Plate 29. 



Chitinous Skeleton and Principal Muscles of the Penis and 

 Corkscrew-organ of the Male Rat-flea, from the Left 

 Side. 



P, penis; e.p., external plates of the posterior end of the body; 

 b. 1 , chitinous bar, an outgrowth of the dorsal integument ; 

 b. 2 , chitinous bar arising from the ventral-posterior end of the 

 penis; l.r.m., lateral retractor muscles running from b. 1 to b. 2 ; 

 m.r.in., median retractor muscle running from b. 1 to an out- 

 growth of the dorsal side of the penis ; l.m., lateral muscle 

 running from the side of the penis to the body -wall; p.m., pro- 

 tractor muscle, running from b. 1 to the penis; c.s.o., corkscrew- 

 organ ; ax., its axial skeleton ; d., the urethral duct ; sp.z., sp z., 

 spermatozoa in the duct, indicating its course where the cork- 

 screw-organ passes into the penis, x 150 linear. 



Plate 30. 



Details of the Male Reproductive System more highly 



magnified. 



A, a portion of one of the coils of the "corkscrew-organ," seen 

 from the lower surface; d., the urethral duct, running at the 

 extreme outer edge of the spiral; ax., the chitinised axis of the 

 spiral; running from ax. to d. are the superficial radiating muscles, 

 clearly seen ; below the radiating muscles two structures are 



