320 DESCRIPTION OF THE PLATES. 



d 2,. Last or ninth testis of right side. 



d 3. Sixth testis, displaced outwards so as to show its connection with the 

 vas deferens. 



e i. Segmental organ or nephridium. 



e i. Segmental organ or nephridium. The testis is displaced outwards. 

 In relation with it is a Cdecal process from the nephridium, the testis 

 lobe, which is surrounded by the perinephrostomial sinus. The vesicle 

 by which the nephridium opens externally lies just to the right of the 

 line from the letter. See pp. 221-3, ante. 



f. Ductus ejaculatorius of left side, leading from the convoluted portion 



of the vas deferens to the base of the prostatic body. 



g. Prostatic body. 



h. Muscular penis, surrounded where it passes out of the integument by a 

 strong sphincter. This orifice lies in the second annulus of the 

 eleventh somite (Whitman). 



i. Ovarian sac of left side, carried upon one of the short oviducts. The 

 ovarian sac of the other side is seen on the farther side of the nerve- 

 cord, underneath which its oviduct passed. 



y. Muscular vagina, in which after sexual congress the spermatophore is 

 found. Between the vagina and the two oviducts, a common oviduct 

 intervenes, which takes a tortuous course, and has its coils surrounded 

 by a mass of loose tissue, composed of unicellular glands, which are 

 probably the main agents in the secretion of the albumen which 

 envelopes the eggs in the cocoon. The azygos character of the two 

 generative outlets is especially noteworthy. 



