180 THE ANNELIDES. § 167, 
§ 167. j 
The genital organs of the Lumbricini are very difficult of dissection ; 
for often those of both sexes are intimately united together into a common 
mass. It is certain, however, that the male and female orifices are always 
in pairs and situated at the anterior extremity of the body, near the ven- 
tral median line.” 
These orifices communicate with more or less numerous glands, sacs, and” 
pyriform or cylindrical vesicles. 
Their nature as testicles, ovaries or sperm-receptacles, is known only hy 
their contents. As yet it has been possible to trace only very imperfectly 
their excretory ducts. With some, two of these caecal organs have been 
observed intersuscepted in each other. The internal one contained sperm- 
atic particles, and should therefore be regarded as a testicle; while the 
outer one contained at its base, eggs and egg-germs, and cught therefore to 
be taken for an ovary.® 
The larger Lumbricini appear to be without copulatory organs, the 
collar situated back of the genital orifices, taking their place. With many, 
it is situated chiefly on the back, but terminates on the belly with two long 
lateral swellings, which, during coition, seize those of the other individ- 
ual.® This collar, moreover, is composed of a mass of glandular follicles, 
which copiously secrete, during the sexual period, a white, viscous liquid. 
It is then very fully developed, but at other periods it is scarcely visible. | 
The belt which is developed near the genital openings of the smaller Lum- 
1 With Lumbricus terrestris, the two anterior‘ 
genital openings are male, and the two posterior, 
female. These have been figured by Montegre 
(loc. cit. fig. 2, a. .), Leo (De Struct. Lumbr. ter- 
restr. Tab. I. fig. 2), and by Morren (loc. cit. 
Tab. III. fig. 2). With Saenuris, and Nais, I 
have also found these two pairs of genital openings. 
2 This invagination of the testicle in the ovary 
has been distinctly observed by me with Saenuris 
variegata, and Nats proboscidea. From H. 
Meckel’s late researches upon the very compli- 
cated genital apparatus of Lumbricus terrestris, it 
appears that there are three pairs of seminal vesi- 
cles and testicles ; these last being intimately joined 
with as many ovaries (Muller’s Arch. 1844, p. 
480, Taf. XIII. fig. 12). It is probable that here 
the testicles and ovaries are also invaginated, and 
that the vesicles which have usually been taken for 
testicles are only vesiculae seminales; see Mor- 
ren, loc. cit. p. 175, Tab. VII.-X. and T'reviranus, 
in his Zeitsch. f. Physiol. V. p. 154, Taf. VII. How- 
ever, as yet I have been unable to trace to their ter- 
mination, the excretory ducts of the testicles and 
ovaries which are invaginated together. 
This point is all the more difficult, for, as Duges 
appears to represent (Ann. d. Sc. Nat. XV. 1828, 
p. 328, Pl. IX. fig. 2, or Isis, 1830, Taf. IIL. 
Tab. 9, fig. 2), the vas deferens is probably 
invaginated in the oviduct. Many observers have 
gone so far as to think that the eggs having escaped 
from the ovary, and fallen into the cavity of the 
body, pass gradually to its posterior portion, and 
are there evacuated through invisible openings. 
On this account, several of them have taken for 
eggs and embryvs, the collections of horny spines, 
and vibrios, which are often found in these animais. 
See above, § 145, note 1; and E. Home, Lect. on 
Comp. Anat. IV. 1823, Pl. CXLIX. 
I have always been astonished that, at the epoch 
of procreation with Saenuris, Euazes, and Nais, 
the two anterior genital openings should i 
bundles of spermatic particles, but never their cells 
of development. Dugés has made a similar obser- 
vation with his Nais filifoarmis (Ann, d. Sc. Nat. 
loc. cit..p. 320, Pl. VI. fig: 2), only he dees not 
specify the contents of the organs. Menge, also, | 
has observed these’ two caeca with Euaves, but he 
unhesitatingly regards. them. as testicles (Wieg- 
mann’s Arch. 1845, I. p. 32, Taf. IIL. fig. 2, aa. 
fig..3). Never having seen any connection between 
these caeca and the testicles behind them, I am 
disposed to think that the two posterior genitah 
openings of some Lumbricini, are the common ori- 
fices of the invaginated testicles and ovaries, while 
the anterior caeca, which are filled at certain times 
with sperm, are two isolated Receptacula seminis. 
During the mutual copulation, the sperm will pass- 
from the testicles into these reservoirs, in order to 
be used during the subsequent deposition of the 
eggs. 
From Hoffmeister’s description (Die bis jetzt 
bekannt. Arten aus der Familie der Regenwiirmer,. 
1845, p. 15) of the copulatory act with Lumbricus 
agricola, it would appear that the sperm remains 
equally distant from the female organs, being re- 
ceived into special fossae, which correspond per- 
haps to the Receptaculaseminis. Nais probos- 
cidea, although having a pair of genital openings, 
has only one testiculo-ovarian canal, both of which 
although invaginated, have a very active and inde-~ 
pendent peristaltic action. They are bifurcated an~ 
teriorly. See Gruithuisen (Nov. Act. Acad. Nat. 
Cur. XI. p. 246, Tab. XXXYV. fig. 4, 5), who has 
very correctly perceived the eggs in the bottom of 
the ovarian sac, but not the nature of the invagi- 
nated testicular canal. 
th Lumbricus olidus,.he two copulating 
individuals seize each other su iightly py their col- 
lars, that each of these animais completely envel— 
ops the other by this organ ;, see Hoffmeister, in - 
Wiegmann’s Arch. 1848, I. p. 190, and, De ver~ . 
cate with two caeca which contain sperm and long 
mibus quibusdam, Tab. I. fig. 30. 
