186 MR. M. F. WOODWARD ON [Mar. Ij 



condition, and possibly have not thus far been functional, although 

 the large size of the cells in some of them does not preclude the 

 possibility of their future maturity. 



With regard to the oviducts, although the specimen was most 

 carefully dissected and thoroughly examined, only one pair of these 

 ducts was to be seen, and that in the position of the typical single 

 pair of the normal worm : that is, related to the mesentery between 

 the 13th and 14th somites, opening into the body-cavity of the 

 former and on to the exterior on the latter. And neither externally 

 nor internally could any trace of accessory oviducts be discovered. 



It is interesting to note in Bergh's'^ description of the presence of 

 additional ovaries that he, being unable to discover additional 

 oviducts, concluded that the ova from the supernumerary ovaries 

 must necessarily be lost. 



This might probably be the case with some of the ova, but if many 

 were shed into the body-cavity (as would happen supposing all these 

 ovaries to be functional), it seems possible that some would find their 

 way through the circum-neural arcade, which puts the various sub- 

 divisions of the body-cavity into communication with one another, 

 and through which the perivisceral fluid circulates ; and, if so, there 

 would seem to be no difficulty in their finding their way into the 

 13th somite, and then out through the oviducts. 



Beddard^ has recently shown reason to believe that "in Acantho- 

 drilus the genital funnels and a portion at least of the ducts are 

 formed out of nephridia," and though not definitely proved for Lum- 

 bricus, it is probable that they are there formed by a modification of 

 the same process. In view of this it seems strange that an animal so 

 rich in ovaries, and with so much material in the way of segmental 

 organs out of which to fashion oviducts, should have only developed 

 a single pair. 



Passing from Lumbricus to the allied genera, it is not so rare to 

 find the animal normally possessing two pairs of these glands. 

 Beddard has described a number of such forms. Thus, Perionyx^ 

 has normally two pairs of ovaries, and is further interesting from 

 the fact that these structures vary in position from the 9th to the 

 16th segment. Phreoryctes^^^ and TJrochceta^ possess two pairs of 

 ovaries, situated respectively on segments 12 and 13. Also in 

 Eudrilus', Acanthodrilus^ , and Phreodrilus^ Beddard finds strong evi- 

 dence for the belief that they also possess an additional pair of ovaries. 



^ Log. cit. p. 308, footnote. 



^ " On the Homology between the Genital Ducts and Nephridia in the 

 Oligochseta/'P. E. S. Lend. 1890, p. 452. 



'' "On a new and little-known Earthworm, with an account of the variations 

 of Perionyx excavatus," P. Z. S. 1886, p. 308, 



* " Affinities of Phreoryctes," T. E. S. Ed. vol. xxxv. p. 629. 



* " Eeproductive Organs of Phreoryctes," Ann. & Mag. Nat. Hist. ser. 6, i. 

 p. 389 (1888). 



" " Certain Points in the Structure of Urochmta," Q. J. M. S. n. s. vol. xxix. 

 p. 235. 



■^ " On the Anatomy of Earthworms," Q. J. M. S. n. s. vol. xxx. p, 421. 

 ■^ " On Phreodriluf<," T. E. S. Ed. vol. xxxvi. (1890) p. 287. 



