TUBIFEX. 377 



VII. The Oviducts. 



There has been a considerable difference of opinion 

 amongst earlier observers as to the position of the oviducts 

 in most members of the Tubificidse. Without going into 

 the whole history of the question, we may notice that 

 D'TTdekem (1855) believed that in Tubifex rivulorum the 

 oviducts were connected with the male ducts, indeed 

 that they actually surrounded the terminal portion of the 

 vasa deferentia. His views were supported by later 

 observers, such as Claparede (1861) and Eisen (1885). 

 Vejdovsky at first was inclined to agree with D'Udekem's 

 description of the relations between these two ducts; but 

 later he changed his opinions, and came to the conclusion 

 that the oviducts are situated between segments 11 and 12. 

 This conclusion was based upon certain experiments 

 which he performed. For example, he kept worms in 

 certain chemical reagents, and observed the extrusion of 

 the eggs between these two segments. 



For some time I was unable to identify the oviducts 

 in my sections, but Mr. E. S. Goodrich, F.R.S., was 

 kind enough to lend me some of his slides in which they 

 were shown quite plainly. Since then, on a re-examina- 

 tion of my own preparations, I have been able to 

 distinguish these structures, though much less clearly 

 thai] in those of Mr. Goodrich — to whom 1 wish to express 

 my indebtedness. 



There can be no doubt that, while the oviducts are 

 small and comparatively inconspicuous, they are 

 normally present, at any rate in the fully mature worm. 

 There is a single pair lying in the intersegmental line 11, 

 12 (PI. I, fig. 2, ovi.). The duel is very short, and opens 

 internally by a wide, funnel-shaped opening into the 

 coelomic cavity of segment 11, while the external opening, 

 which is small and inconspicuous, lies in the same longi- 

 tudinal line as the male openings. 



