REPRODUCTIVE SYSTEM 67 



developed they form conspicuous milk-white 

 bodies at the sides of the oesophagus, and over- 

 lapping it. 



i, A pair of anterior lateral vesiculae seminales lie 

 in segment ix. They are opaque white bodies 

 attached to the posterior wall of the segment, 

 one at each side of the oesophagus. 



Some species of earthworm have a similar 

 pair in segment x, but in Lumbricus terrestris 

 these are not developed. 



ii. Two pairs of posterior lateral vesiculae seminales 

 lie in segments x. and xi. respectively. They 

 are very much larger than the anterior 

 vesiculae, especially at certain seasons, and 

 are attached to the anterior septa of their 

 respective segments, somewhat nearer the 

 median plane than the anterior vesiculae. 

 iii. A thin -roofed median vesicula seminalis, of 

 considerable size, is situated in each of the 

 segments x. and xi. below the oesophagus, 

 which must be removed to expose them. 

 Within each are a pair of testes and a pair of 

 seminal funnels. With the anterior of these 

 median vesiculae the anterior lateral vesiculae 

 and the first pair of posterior lateral vesiculaa 

 communicate. The second pair of posterior 

 lateral vesiculae open in similar fashion into 

 the second median vesicula. 



b. The testes are two pairs of flattened digitate bodies 



of small size, attached to the septa in front of 

 segments x. and xi. respectively, and projecting 

 freely into the cavities of the median vesiculae 

 seminales, not far from the nerve-cord. 



To see the testes, open the two median vesicula seminales 

 without injuring the structures within them. Wash carefully. 



c. The seminal funnels are large, opaque, white, much- 



folded membranous funnels, of which one pair is 



F2 



