516 FRANK E. BEDDARD. 
gonads were absolutely indistinguishable from each other in 
their shape and relations to the septum, body-wall, and nephri- 
dial funnel; neither were there any ascertainable differences in 
their minute structure. 
In stage D the gonads have become much more evident, 
and, indeed, they hardly differ in minute structure from those 
of the newly hatched worm. Figs. 13 and 14 illustrate the 
gonad and a portion of the genital ducts. In fig. 14 the 
gonad is shown attached to the front surface of the septum 
(spt.), and a portion of the genital duct (vas def.) is seen 
behind the septum. The gonad is frayed out into a number 
of processes. In fig. 13, which is a few sections further 
forward, the commencement of the funnel of the generative 
duct is shown ( funn.) ; the gonad is seen to be partly attached 
to the funnel. Fig. 15 represents a section through one of 
the gonads of another individual; the “ protova” (g. ¢.) are 
peculiar in shape, being prolonged into a stalk ; round these 
lie accessory cells (p. c.), which do not, I imagine, develop into 
sexual products. 
§ Genital Ducts. 
The development of the genital ducts in Lumbricus has 
been studied by Bergh (11), who has arrived at the following 
results, which I state for the purposes of comparison with 
Acanthodrilus. 
Bergh’s results in the main confirm those of Vejdovsky 
upon certain aquatic genera (2). The first part of the duct to 
appear is the funnel, but this is not developed until after the 
young worm has left the cocoon. Previously to this the gonads 
have been formed, but only nephridia are to be found in the 
genital segments. When the funnels do put in an appearance 
they are formed beside the nephridial funnel, but are perfectly 
distinct from it though in actual contact (Bergh, 11, pl. xxi, 
figs. 19, 21). The ciliated epithelium of the nephridial funnel 
is figured by Bergh as totally distinct from the, at first, non- 
ciliated epithelium of the genital ducts. Although no actual 
observations were made, Bergh is inclined to confirm Vejdov- 
