268 FKANK E. BEDDARD. 



the paired orifices upon Segment 13, Michaelsen considers 

 these to be the remains of the spermathecee which open on to 

 this segment in Eudriloides, Teleudrilus, and other 

 Eudrilids, This identification cannot be regarded at present 

 as being anything more than possible. The spermathecae of 

 Lumbricus are developed as involutions of the epiblast, and 

 if the course of development of the spermathecse in the Eudri- 

 lidse is the same, it is not likely that they could ever come to 

 be represented by pores. 



Considering the matter necessarily in the absence of any 

 knowledge of the development of the parts in question, it 

 seems possible to regard these pores as the rudimen- 

 tary equivalents of oviducts. 



In describing the structure of Eudrilus I have pointed out 

 that there are apparently two pairs of oviducts present in that 

 worm. One pair, represented in all other earthworms, open 

 on to the 14th segment ; the other pair are short tubes con- 

 nected with the sac involving the ovary in Segment 13 ; they 

 open in common with the spermatheca and the other oviducts 

 on to the 14th segment. 



These peculiarly modified organs in Nemertodrilus are 

 quite intelligible on the hypothesis that they have been 

 derived from the corresponding organs of Eudrilus, 



I pointed out that there was some evidence in favour of 

 regarding the oviducts of Segment 13 as being in course of 

 degeneration ; they are very short, with feebly developed walls, 

 and the lining epithelium is not ciliated. This reduction is 

 carried further in Nemertodrilus; the oviducts are reduced 

 to the condition of the oviducts in the Enchytreeidse, where there 

 is little more than a pair of orifices. At the same time the 

 coelomic cavity of the segment is greatly reduced ; this renders 

 it easy for the ova to reach the exterior through the oviducts 

 of the 14th segment, which are apparently as well developed 

 as in Eudrilus. 



In Teleudrilus there is no trace (?) of the oviduct of Seg- 

 ment 13, and, except for the continuity of ovarian sac with 

 the receptaculum, the female reproductive organs of this genus 



