THE POLYPI. 
$$ 47, 48. 58 
§ 47. 
I. With those polyps which are not sexless, and whose alimentary canal 
hangs free in the cavity of the body, the sexual organs are situated in this 
last. They often escape attention, since they are scarcely at all developed 
except at the sexual epoch. Both ovaries and testicles frequently 
appear as riband-like bodies, which, being attached by one extremity alone 
to the stomach, move freely in the general cavity of the body. Sometimes, 
however, they are attached longitudinally by one of their borders, like a 
mesentery, the opposite border being free. In other cases, again, they are 
attached directly to the sides of the body. 
The eggs and spermatic particles pass directly from the sexual organs 
into the cavity of the body. In Coralla having individuals of both sexes, 
fecundation takes place in the cavities of their bodies, which connect with 
each other.” With the others, however, the individuals of which are of 
one séx alone, the surrounding water is the medium of fecundation, by 
transporting the spermatic particles unaffected to the eggs; and this being 
performed by the aqueous circulation before mentioned, impregnation takes 
place in the cavity of the body. 
§ 48.* 
The variations of the internal genital organs in the different families are 
as follows : 
1. With the Bryozoa, a riband-like ovary and testicle are suspended 
from the extremity of the stomach. In these organs are developed only 
two to four eggs or fasciculi of spermatic particles, from cells arranged like 
a string of pearls.  . 
The eggs, of which the germinative vesicle and dot disappear at a very 
early period, are detached from the ovary before their shell is well formed, 
and are set in motion by the cilia of the cavity of the body. Usually they 
are flattened, and at first enveloped by a thin and colorless membrane, 
which soon becomes thicker and darker, and has upon its borders a clear, 
1 With Tendra zostericola, which is allied to 
Flustra, the Polyps are contained in cells closely 
bound to each other. But the cells of the males 
communicate with those of the females by an open- 
ing, through which the spermatic particles pass 
into the cavity of the body of the female (see 
Nordmann, Ann. a. Sc. Nat. XI. 1839, p. 191). 
tesla! 
and the particleq' ‘themselves are the metamor- 
phosed nuclei ,6f these cells, exactly as in other and 
higher animals. They have invariably, as far as I 
am acquainted, a cercaria-form consisting of a solid 
head, to which is attached a most delicate tail. 
The shape of this head, when studied carefully with 
the best powers, presents differences of zoological 
import, Sometimes it is pyriform (Tubularia, 
Actinia), sometimes conical (Astrangia), while 
among the Bryozoa it is long-oblong with Alcyo- 
nella. I cannot therefore agree with Kalliker 
(Cyclop. Anat. Art. Semen. 1849, p. 497) as to the 
mode of development of these particles with these 
animals. —- Ep. 
5* 
1 See, for Aleyonella stagnorum, Meyen (Isis, 
1828, Taf. XIV. fig. 1), for Plumatella cristata, 
Dumortier (loc. cit. pl. I. fig. 8, u, u) and for 
Cellaria avicularia, Nordmann (Obs. sur la 
Faune Pontique, p. 679, fig. 4, A. n).f 
*[§ 48.] In an emendatory note at the end of 
the volume, the author remarks: “Sections 2d and 
8d of this paragraph should be omitted, since the 
genital organs, with all the Anthozoa, are attached 
on the internal surface of the visceral cavity. See 
Frey and Leuckart. Beitr. &c. p. 13.” I have, 
however, allowed them to remain, for the sake of 
their notes. — Ep. 
+(§ 48, note 1.] My own researches in 1851 
have shown me that with Alcyoneldia the sexes are 
separate. The testicles and ovaries consist of pedun- 
culated sacs, closed at first, but which are rup- 
tured on the mature devel t of their 
— Ep. 
