260 WILLIAM BLAXLAND BENHAM. 
The sperm duct in Earthworms opens internally by a funnel, 
or “ ciliated rosette.” Usually the sperm duct, which is single 
at the external pore, becomes double anteriorly, and ends in a 
ciliated rosette beneath each seminal reservoir situated in the 
same somite; this ciliated rosette is usually enclosed in the 
reservoir, and though Perrier describes it as sometimes free, 
e.g. in Pericheta Houlleti, yet it is probably so only in 
the immature worm. 
Only in one case, Pontodrilus Marionis, are the ciliated 
rosettes in front of the seminal reservoirs, being here in somites 
x, x1, whilst the reservoirs are in somites x1, x11. Another 
variation comes about by the presence of four separate sperm 
ducts, each with its external pore, asin Acanthodrilus and 
Moniligaster. In Anteus no sperm ducts are known, and 
the nephridia of the clitellar region are supposed by Perrier 
to function as sperm ducts. 
Accessory Organs.—lIt is only in a few genera that the 
sperm duct is without a gland or enlarged portion near the 
pore, e.g. Lumbricus, amongst the Anteclitelliani, Uro- 
cheeta [as well as Microcheta, and other forms that I shall 
describe later on], amongst the Intraclitelliani. 
In Titanus the sperm duct opens into an enlarged, flat, 
muscular sac, which does not seem capable of protrusion. 
There is no gland, or “ prostate ” as it is usually called. 
In most forms, whose sete have been examined, it is found 
that those on the somite at which the male pore opens are more 
or less modified. Thus, in Lumbricus they are slightly 
modified; in Rhinodrilus they are elongated and orna- 
mented, as they are also in Urocheta. 
In Acanthodrilus this modification is carried further. At 
each of the four male pores is a bundle of setz, usually 
recurved, enclosed in a sac opening close to the male pore, and 
the distal portion of the doubtful prostate is muscular, and pro- 
bably protrusible. The most complete “penis” is found in 
Eudrilus, where a strong, recurved chitinous hook is enclosed 
in a spherical sac on each side of somite xvii, where the male 
pore opens. Opening into this sac, besides the sperm duct is an 
