691 



ON THE REPRODUCTIVE SYSTEM OF DIGAHTER 

 (DIDYMOGASTER) SYL VATIC US, Fletch. 



By Sarah O. Brennax, M.A., B.Sc. 

 (From the Biological Laboratory of Sydney Unirersity.) 



(Plates liii.-liv.) 

 The present paper contains an account of the reproductive 

 organs of the above-mentioned Earthworm, based on dissections 

 and serial sections, and is to be regarded, so far as concerns this 

 system of parts, as supplementary to the account given by Mr. 

 J. J. Fletcher in his diagnosis of the genus, published m the 

 Proceedings of this Society for the year 1886.* 



Female organs.-My observations on the female organs are in 

 complete agreement with those of Fletcher as described by him. 

 They comprise a pair of ovaries, a pair of oviducts, and three 

 pairs of spermathecse. 



(a) Ovaries-The two ovaries (fig. 1, ov.) are attached to the an- 

 terior septum of segment xiii., and hang freely from it into the 

 ccBlom. In the mature worm the free end of each ovary is frayed 

 out into a number of processes consisting of strings of ova in 

 different stages of development. The mature ovum measures in 

 diameter about -08 mm , is spherical in shape and invested by a 

 definite membrane. Its nucleus is placed excentncally, and 

 contains a deeply-staining nucleolus. In young females the 

 ovaries resemble the testes in shape. Egg-sacs are not present. 



• Fletcher, J. J. Notes on Australian Earthworms, Part i. P.L.S.N.S.W. 

 (2) i. 1886, p. 554. 



