A>f OLIGOCH.ETE WORM. 



313 



According to Michaelsen (9), " The reproductive apparatus of 

 Enchytraaids varies very little. The testes are formed on the 

 posterior side of the septum between segments 10 and 11, and 

 the ovaries on dissepiment 11/12. Two sperm-funnels are present 

 in segment 11. The sperm-ducts lead from the sperm-funnels, 

 and each opens in a penis-like swelling on the ventral side of 

 segment 12. A pair of oviducts open on the ventral side 

 of segment 13. The spermathecse lie in segment 5 and open 

 externall)' on the intersegmental furrow^, segments 4/5. The 

 clitellum covers segment 12 and often parts of segments 11 

 and 13." 



Sjjermaiheca;. — In Enchytrceus pellucidus the spermatheca? are 

 present in segment 5. In the fully mature worm they are large 

 organs, filling up practically the whole of the body-cavity in that 

 segment. They open at intersegment 4/5. 



The ampulla of the spermatheca is large and pear-shaped, 

 with the narrow end anterior. In a mature worm, after copulation 

 has taken place, the spermatozoa can be seen through the 

 walls of the ampiilla, giving it a definite golden-brown colour. 

 The duct leading to the exterior is not so long as the ampulla, 

 and in E . 2)elh(,ci(:lns has not got a definite rosette of glands around 

 the external opening. Fig. 3 (PI. XLYI.) shows the sperma- 

 theca of E. cdbidios, with the rosette of glands round the external 

 aperture — it had been dissected away from the worm, and there- 

 fore the connection wdth the gut is not seen. To show how this 

 spermatheca differs from the spermatheca in other species, I give 

 a figure of the spermatheca of a mature specimen of Enchrjtrcp.us 

 argenleus. In this worm the ampulla, of the spermatheca is 

 merely a slight swelling of the spermatheca! tube. 



Text-fi<r. 67. 



Spermatheca oi Enchytravs argenteus, for comparison with iig. 3 (PI. XLVI.) 



spz., sperms in the ampulla ; amp., ampulla ; op. to g., opening of 

 spermatheca into the gut. 



The spermatheca always communicates with the gut (PI . XLYIII. 

 fig. 16), sometimes by a long connection and sometimes by a 

 short one. In E. j^ellucidus the connection with the gut is 

 short and wide. The fact that the spermatheca communicates 



Proc. Zool. Soc— 1913, No. XXI. 21 



