178 $$ 165, 166. 
THE ANNELIDES. 
With the Nemertini, and Branchiati, the sexes are upon separate individ- 
uals, and the genital organs are composed simply of testicles and ovaries. 
§ 165. 
The structure of the genital organs of the Nemertini is yet quite obscure. 
Th2 few researches hitherto made only furnish the general result that the 
sexes are separate. , 
There are numerous glandular follicles situated laterally in the paren- 
chyma of the body between the skin and the intestinal canal, which are 
closely aggregated and serially arranged. 
With some individuals, these follicles contain eggs, and with others, 
sperm. ‘They ought, therefore, to be regarded as ovaries and testicles. 
Each follicle opens separately upon the surface of the body.” There are 
very contradictory statements as to whether these animals have, or have 
not, copulatory organs. 
According to some Naturalists, the worm-like organ, concealed in a canal 
extending along the back, and which, with both sexes, is often protruded 
and moved actively about, ought to be regarded as an excitatory organ, — 
although no connection between it and the testicles or ovaries, has as yet 
been found. According to others, it is a proboscis unconnected with the 
genital organs. 
§ 166. | 
The disposition.of the genital organs of the Hirudinei and Lumbricini, 
is essentially different. 
The first have only two simple genital openings, — one male, the other 
female, both situated, one after the other, upon the median line of the ven- 
1 See Duges, Ann. d. Sc. Nat. XXI. 1830, p. 76, 
PL. II. fig. 5 (Polystemma (Prostomum) arma- 
zum) ; Johnston, Mag. of Zool. I. p. 532, Pl. XVIT. 
fig. 2°*, 6°*, Pl. XVIII. fig. 3° (Wemertes and 
Borlasia) ; Orsted, Entwurf. einer Beschreib. d. 
Plattwirm. p. 22, Taf. III. fig. 41 (Tetrastemma 
waricolor)} Kélliker, Verhandl. d. schweiz. na- 
turf. Versamml. zu Chur. p. 91 (Wemertes); and 
Rathké, Danzig. Schrift. loc. cit. p. 98 (Borlasia 
striata). This last author has not seen the orifices 
of the genital organs. Quatrefages (Régne anim. 
illustr. loc. cit. Pl. XXXIV. fig. 1, n.n.) did not 
see them with Nemertes Camilla, and Johnston 
is also silent on this subject. According to Orsted 
(Entwurf. &c. loc. cit. p. 25, Taf. IIL. fig. 47, of 
Notospermus flaccidus) the Nemertini secrete 
from the whole surface of their body, a gelatinous 
mucus, which surrounds the eggs, and thus forms 
an envelope into which they can draw their bodies. 
Something similar to this occurs with the Lumbri- 
cini and Hirudinei. See below. 
2 The Nemertini being of distinct sexes, this or- 
gan can be regarded neither as a penis, nor as an 
everted spermatic vessel, as Huschke has done 
Asis, 1830, p. 682, Taf. VII. fig. 5). More prop- 
erly could it be considered, with Orsted (Entwurf. 
&Xc. p. 25), as an excitatory organ; although Rathké 
«Danzig. Schrift. loc. cit. p. 100, and Nov. Act. Acad. 
Nat. Cur. XX. p. 233) regards it as of a tactile, 
and Kélliker of a prehensile nature (Verhandl. d. 
schweiz. p. 90). Other observers agree with 
Khrenberg (Symb. phys. loc. cit.) that it is an in- 
destine and an everted oesophagus, its orifice being 
@ mouth ; but this is undoubtedly erroneous. With’ 
Polystemma armatum (Duges, Ann. d. Sc. Nat. 
loc. cit. p. 75, Pl. IL. fig. 5) Tetrastemma_vari- 
color (Orsted, Entwurf. &c. p. 23, Taf. ITI. fig. 
41), and Nemertes (Johnston, Mag. of Zool. I. p. 
630, fig. 2; Quatrefages, Régne anim. illustr. loc. 
cit. Pl. XXXIV. fig. 2,:and Kélliker, Verhandl. d. 
schweiz. &c.) there is at the centre of this organ a 
dart pointing forward, which is horny, atcord- 
ing to Dugés, and calcareous, according to Orsted. 
On each side of this dart, there is a reservoir of 
many others, smaller and yet imperfect, destined, 
probably, to replace the former when lost. Dugés, 
Johnston, and Quatrefages, who regard this or- 
gan as an intestinal canal, and Kélliker, who con- 
siders it prehensile, all regard these darts as a kind 
of teeth; but Orsted thinks they serve to excite 
the genital organs. For my part, they involunta- 
rily remind me of the darts of the Helicina. 
{Additional Note.) —I have now satisfied myself ' 
upon living individuals of I’etrastemma, that the 
eggs can escape from the visceral cavity through 
numerous lateral openings in the wall of the body 
Iam also satisfied that with the Nemertini, the 
walls of the digestive canal (the middle body-cavity 
according to Quatrefages) are not the points of 
departure of the genital organs, as Quatrefages 
thinks, and who also would regard as a digestive 
tube the snout of these animals, an organ which is 
yet enigmatical. The very detailed figures which 
this naturalist has given (loc. cit.) of the walls of 
the digestive canal of these animals, present nothing 
like an ovary, and show no trace of the presence 
of germs. 
