EARTHWORM 



347 



Reproductive Organs 



The earthworm is hermaphroditic, the organs of both sexes be- 

 ing present in every animal. The seminal receptacles, oviducts, and 

 ovaries are female organs, and the testes and seminal vesicles are male 

 organs. The seminal vesicles are three pairs of light-colored bodies 

 located in segments IX, XI, and XII. In sexually mature individ- 

 uals they may extend back through the septae as far as the fifteenth 

 segment. If their contents are examined with a microscope, they 



nn ^i^'tu,? ^~^^?''°^^^/^^'® organs and nervous system in segments VIII to XV of 

 nnH YT f^ I^*,^ portion of the seminal vesicles has been removed in segments X 

 ova rvV: o^ disclose the testes and sperm funnels, es. egg sac ; nc, nerve cord ; ov, 

 Hpf^ro«5^ ' semmal funnel; sm, septum between two somites: Sji, sperm duct (vas 

 vAcfJiJ^ f openmg in the fifteenth somite r sr, seminal receptacle; sv, seminal 

 C? V Mosby Com ^ oviduct. (From White, General Biology, published by The 



are seen to contain the various stages of developing spermatozoa 

 coming from the sperm mother cells. The testes are the two pairs 

 of very minute bodies projecting into the seminal vesicles in seg- 

 ments X and XI and cannot be seen without first removing the 

 dorsal part of the seminal vesicles. The union of the vasa efferentia 

 coming from the vesicles on each side forms a single pair of vasa 



