III.] THE EARTHWORM. 269 



mediately convoluted, uniting in segment 12 with 

 its fellow to form the vas deferens. Follow this 

 back, it runs longitudinally midway between the 

 nervous axis and the exterior, passing out on seg- 

 ment 15. 



e. The testes (visible only in sexually immature speci- 

 mens), two minute white bodies truncated pos- 

 teriorly- attached, on either side, to septa 9 10 

 and 10 a i close to the middle line. They pro- 

 ject into segments 10 and n. 



In sexually mature worms these and the ciliated 

 rosettes are both embraced by the enlarged seminal 

 vesicles. 



/. The ovaries, two small conical bodies, attached by 

 their bases to septum 12 13 in a line with e. 

 Their free ends are not unfrequently recurved. 

 They project into segment 13. 



g. The oviducts. Remove the segmental organs from 

 septum 13 14, seize the latter with forceps and 

 turn it backwards the mouths of the oviducts will 

 be seen opening into segment 13 in a line with/ 

 The ducts themselves are very short and closely 

 bound down to the hinder face of the mesenteric 

 septum. They pass outwards and backwards, 

 opening on to the exterior in a line with d. 



h. The receptacula ovorum ; tuft-like appendages of the 

 hind-walls of the oviducts. They project freely 

 into segment 15, and are rendered highly con- 

 spicuous by their great vascularity. 



*". Remove the entire ovary and transfer it to a slide, 

 stain with eosin and examine under a high power. 

 Commence at its free end, and note 



