134 THE BIOLOGY OF THE ANIMAL 



5. The testes.— Number ? Shape ? Note the seminal 

 funnel opposite each testis and prolonged into a 

 tube (vas efiferens), these two tubes uniting in a 

 single tube (vas deferens) which opens out- 

 wardly in segment fifteen. 



Attached to front wall of segment thirteen are 



c. The ovaries. — Position? Number? Size? Color? 



Compare with the seminal vesicles and the testes 

 in all respects. Attached to the posterior wall 

 of the same segment look for two funnels whose 

 tubes, the oviducts, pierce the wall and open ex- 

 teriorly in segment fourteen. Close to the point 

 where the funnel perforates the wall look for the 

 receptacula ovorum. 



Look for small globular bodies in hinder por- 

 tion of segments nine and ten, external to the 

 seminal vesicles, 



d. The spermathecae. — Compare them with the semi- 



nal vesicles, the testes, and the ovaries. Note 

 their openings to the exterior in the grooves be- 

 tween segments nine-ten and ten-eleven, close to 

 the inner side of the outer double row of setae. 

 Make a drawing of the reproductive organs, showing 

 them in their proper segments. If facilities are at hand 

 for doing such work, sections of embedded specimens 

 should be made and the histology of the worm studied. 

 This is especially instructive. For this purpose worms 

 may be killed in strong alcohol (eighty per cent, to 

 ninety per cent.), being left in it for twelve to eighteen 

 hours, then cut into pieces about one inch long and 

 some of the pieces placed in absolute alcohol for about 

 a day. The specimens may then be embedded in cel- 

 loidin or paraffin and sectioned. 



