EARTHWORM. 219 
for in Polycheetes the genital products mature in the general 
body cavity, just as the spermatozoa in the earthworm 
mature in the seminal vesicles. 
(3) From the seminal vesicles the spermatozoa are carried 
to the exterior by means of the vasa deferentia. The in- 
ternal openings of these are large and funnel-shaped, and 
are concealed by the seminal vesicles. Each of the four 
funnels opens into a duct, and the two ducts unite at each 
side to form the two elongated vasa deferentia, which pass 
backwards to open externally on the 15th segment. 
(6) The Female Organs consist of two ovaries and two 
oviducts, each of which has a side receptacle for the eggs. 
(1) The two ovaries are small bodies situated near the 
nerve-cord on the septum between segments 12-13. Each 
is pear-shaped, the stalk of the pear being a string of ripe 
ova. They are more readily seen than the testes. 
(2) The two oviducts open internally on the anterior 
face of the septum between 13-14, and externally on the 
ventral surface of segment 14. Into the wide ciliated in- 
ternal mouths, which lie opposite the ovaries, the ripe eggs 
pass. 
(3) The egg-sac or receptaculum ovorum, near the internai 
mouth of each oviduct, is a posterior diverticulum of the 
septum between segments 13-14. Within it a few mature 
ova are stored. 
(c) Two pairs of receptacula seminis or spermathecze 
receive spermatozoa from another earthworm, and liberate 
them to fertilise the eggs of this one. They are white 
globular sacs, opening in the grooves between segments 
g-to and 10-11, and probably, like the genital ducts, arise 
from modified nephridia. According to some, these sper- 
mathece not only receive and store spermatozoa, but make 
them into packets or. spermatophores. Others say that the 
glands of the clitellum make these packets. At any rate, 
minute thread-like packets of spermatozoa are formed, and 
a pair of them may often be seen adhering to the skin of 
the earthworm about the saddle region. 
When two worms unite sexually, they lie apposed in 
opposite directions, the head of the one towards the tail of 
the other. What happens is that the spermatozoa of the 
one pass into the receptacula of the other. 
