ANNULATA. 233 
éestes ; STEENSTRUP on the contrary thinks that they ought not to be 
considered to be the parts where the seed is formed, but where it is 
collected (as seminal vesicles in the male subject, as burs copulatrices 
in the female). The efferent ducts of these vesicles open externally, 
according to Savieny ; but later writers have failed to discover the 
openings ; rather are they in connexion with the efferent ducts of 
the yellow saccules ; these ducts fall at length into a common canal 
on each side backwards and end with two openings at the fifteenth 
or sixteenth ring of the body. At the origin of these two canals lie 
two small irregular saccules, covered by a thin and glistening mem- 
brane, which according to DucEs and Sreensrrup are filled with 
many convolutions of the efferent canal and form the passage of the 
yellow saccules to the straight part of the canal which runs back- 
wards’. Earth-worms are oviparous, not viviparous; they pair 
during the whole Summer, especially by night, when they creep 
from the earth; but how impregnation is effected, is not yet sufti- 
ciently explained, since the apertures of the sexual organs are not 
brought immediately together. The anterior portions of the two 
worms lie next cach other, but with the heads in opposite directions 
(see in Morren 1.1. Tab. xxv). Thus the part named by Winzis 
Clitellum (saddle) in each of the two worms lies towards the place 
where the sexual openings of the other worm are found. This cli- 
tellum is a round swelling of the body which occupies from six to 
nine rings (in Lumbricus agricola from the 29th to the 36th or from 
the 31st to the 38th ring), and which during the time of copulation 
is more strongly developed, and in young individuals is entirely 
wanting. 
Sp. Lumbricus agricola Horru., Lumbricus terrestris L. (in part), Horr- 
MEISTER Die bekannte Arten aus der Fam. der Regenw. fig. 1; the largest 
species in northern Europe, from eight inches to more than a foot in 
length. 
Family V. Maldanie Sav. Branchie none. Mouth bilabiate, 
inferior. Rudiments of feet provided with sete; the three anterior 
pairs without ventral pinna, the rest with a transverse tubercle, 
‘supplied with uncinate sete, in place of a ventral pinna. 
Clymene Sav. Body cylindrical, with few elongate segments, 
+ The best description and figure of the organs of propagation in Lumbricus were 
given by G. R. Treviranus, Zeitsch. fiir Physiol. v. s. 154—166, Tab. III.; see also 
SreENstRUP, Hermaphroditismus Tilverelse, pp. 35—40, Tab.1. figs. 2—7, and H. Mro- 
KEL in MUELLER’S Archiv, 1844, 8. 480—483. 
