THE ROTATORIA. 
§ 141. 
§ 141. 
Their embryonic development occurs, as in most invertebrate animals, 
through a complete segmentation of the vitellus; and the embryonic cells 
then appear in the segmented portions. 
The newly-hatched embryo has already rotatory and masticatory: organs, 
eye-specks, &c., and the general form of the adult animal.} 
many species was formerly taken for a penis. But 
the incorrectness of this view has since been seen, 
for no one has here observed the copulatory act.’ 
According to Ehrenberg, who regards these ani- 
mals as hermaphrodites, certain parts of the aquif- 
erous system represent the male organs. He 
regards the two lateral bands as testicles, and 
their inferior extremities as vasa deferentia, while 
the contractile vesicle is the vesicula seminalis. 
But these organs contain only an homogeneous 
aqueous fluid, in which there is at no time anything 
like spermatic particles ; moreover they are fully 
developed in the young individuals which then 
have no trace of female organs. 
It would be wholly anomalous that these ani- 
mals should constantly secrete sperm during their 
whole life. One would therefore wholly assent to 
the doubts of Dujardin (Infusoires, p. 587), upon 
this view of Ehrenberg, and some contradictions 
into which this last has fallen upon this subject, 
have been noticed by Doyére (Ann. d. Sc. Nat. 
XVII. 1842, p. 199). Kélliker has also thought 
this view unfounded, and has sought to remove 
the doubts by a search after the spermatic parti- 
cles. He regards as such, with Megalotrocha 
albo-flavicans, the peculiar trembling bodies which 
he has seen in the cavity of the body, since they 
are composed of a pryiform body, to which is 
attached a movable tail. These bodies he affirms 
animals (Froriep’s neue Not. No. 28, 1848, p.. 
17). But this whole observation is somewhat sus-- 
picious, for Kadliker has very probably confounded 
the vibratile lobules of the aquiferous system with 
the spermatic particles, and of which there are four 
with Megalotrocha in the anterior extremity. 
The observation of R. Wagner (Isis, 1832, p. 386, 
Taf. IV. fig. 1, 7) is particularly worthy of atten- 
tion, for followed out, it might lead ‘to the discovery’ 
here of male genital organs. He has described 
peculiar eggs, found frequently by him with Hy- 
datina senta, and whose whole. surface is covered 
with very fine, thickly-set hairs. He has regarded. 
these as in their first stages of development, 
although Ehrenberg (obpandl: d. Berl. Akad. 
1835, p. 154, and, Die Infusionsthierchen p. 415), 
has taken this villous envelope for an alga of the 
genus Hygrocrocis. But these villous envelopes 
have always reminded me of the masses of sperm- 
atic particles in the testicles of leeches and which 
have been figured by Henle as whitish felt-like 
globules (Muiller’s Arch. 1835, p. 584, Taf. XIV. 
fig. 6. a). 
[Additional Note.] Kélliker (Neue Schweiz. 
Denkschr. VIII. Taf. I. fig. 31, a.) having since 
figured the spermatic particles of Megalotrocha 
alboflavicans, my former view that he had con- 
founded these with vibratile organs, is incorrect.” 
1 Kélliker was the first to observe the complete 
are developed in round cells, often l d, and 
he has often counted ten to twenty in the same 
individual. As he also asserts to have seen eggs 
at this time in the same individual, this would cer- 
tainly be a proof of the hermaphroditism of these 
more than the tail of a spermatozoon.” He very 
justly concludes that they cannot at present be 
definitely regarded as spermatic particles. — Ep. 
* [§ 140, note 2.] The subject of the form and 
character of the spermatic particles of the Rotatoria 
is quite interesting, as it may perhaps throw some 
light on the position of these animals in the animal 
kingdom. As yet, however, we have very few 
observations, and even these are not fully defi- 
nite. ~ 
Schmidt (Vergleich. Anat. &c. p. 268, note) 
speaks of the spermatic particles of Zuchlanis 
macrura, as being cercaria-form. 
Leydig (Siebold and Kélliker’s Zeitsch. III. 
Hit. 4, p. 471) has given those of Lacinularia as 
composed of a nuclear body from which radiate 
many tails, like these particles with the Decapods, 
See Taf. XVII. fig. 2.— Ep. 
+ [End of §141.] We are indebted to Leydig 
(Zur Anat. u. Entwickelungsgesch. d. Lacinularia 
socialis, in Siebold and Kéiliker’s Zeitsch., III. p. 
tion of the eggs, with Megalotrocha 
(Froriep’s neue Not. loc. cit.). It wholly escaped 
the observation of Ehrenberg amid his numerous 
researches upon the eggs of these animals; see 
Abhandl. d. Berl. Akad. 1835, p. 152.$ 
452) and to Hualey (loc. cit. p. 11-15), for extend- 
ing our knowledge in this direction. They have 
carefully observed the development of Lacinu- 
laria, and the phases correspond exactly with 
those of Megalotrocha as described by Kélliker. 
But beside this ordinary mode of reproduction, 
they have observed another which is a sexual and 
analogous if not identical with what has beet 
observed with some of the lower Crustacea (see 
infra § 292), — propagation by the so-called hiber- 
nating eggs. Their observations throw light on the 
whole of this interesting subject, and have fully 
confirmed me in my previous conjectures that these 
“Ova? are only gemmae having their exact repre- 
sentative in the bud-like eggs of the viviparous 
Aphides. — Ep. 
t[§ 141, note 1.] Kéllixer’s observation above- 
mentioned on Megalotrocha, has since been con- 
firmed by Leydig (Isis, 1848, p. 170) who has 
observed it likewise with Notommata and Euch- 
lanis.— Ep. 
