54 $$ 49, 50. 
THE POLYPI. 
transparent ring. In Alcyonella and Plumatella, the eggs are of an oval 
shape, and of a dark-brown color. In Cristatella mirabilis, Dal. (Crista- 
tella mucedo, Cuv.), they are lenticular and clear brown, and have this re- 
markable peculiarity: ® Upon both sides of the encompassing ring are a 
number of double-pointed hooks, which, at first, are imbedded in a gela~ 
tinous substance ; but ag this last is dissolved by water, they.become free, 
and adhere to plants and other bodies. 
2. With many Anthozoa, having a cavity of the body, the sexual or~ 
gans are attached in the form of.bands along the external face of the 
stomach. These are numerous, and during the epoch of reproduction their 
free borders are often plicated, and have a botryoidal aspect. : This form 
is quite apparent in the Actiniae, where these organs are contained in sep- 
arate chambers of the cavity of the body. The same is true of the Ed- 
wardsiae.© With Veretillum © and Alcyonium these organs form mesen- 
teric divisions which descend deep into the cavity of the body. 
3. In Alcyonidium elegans ® and Tubipora musica ® these organs are 
attached to the internal surface of the cavity of the body, and have a pli- 
cated mesenteric form. 
§ 49. 
The laying of the eggs takes place in different ways with those Polyps 
having internal sexual organs. 
through the openings near the anus.” 
With the Bryozoa it probably occurs 
With the Anthozoa, however, they 
pass into the stomach through its abdominal orifices, and thence are 
ejected through the mouth. In the viviparous Actinia, the young, devel- 
oped at the base of the stomach, are expelled in the same manner. 
g50. 
II. Many Anthozoa, which have no general cavity. of the body, have 
external sexual organs. 
2 Raspail, loc. cit. pl. XII. fig. 10-12, pl. XIV. 
fig. 4-8, and pl. XV. fig. 5. 
3 Turpin and Gervais, Ann. des Sc. Nat. VII. 
1837, pl. IIL. A. fig. 2-4, and pl. IV. A. fig. 1-6. 
4 Wagner. Wiegmann’s Arch. 1835, I. Taf. II. 
fig. 1; also Icones zoot. Taf. XXXIV. fig. 22. 
5 Quatrefages. Ann. d. Sc. Nat. loc. cit. pl. I. 
fig. 7, and pl. IT. fig. 10. 
6 Carus and Otto. Erlauterungstafeln, Heft. IV. 
Taf. I. fig. 19; also Wagner, Icones zoot. Taf. 
XXXIV. fig. 2. 
7 Milne Edwards. Ann. d. Sc. Nat. loc. cit. pl. 
Pail fig. 4; pl. XV. fig. 6, 8, and pl. XVI. fig. 
8 Ibid. p. 829, pl. XII. fig. 3, pl. XIII. fig. 2, 7. 
9 Rymer Jones. Outlines, loc. cit. p. 36, fig. 9, 
after Lamourouz. 
10 Kélliker’s observation upon the sexual organs 
*[§ 48, note 10.) With the Actinina, some of 
the lamellae which partition off the visceral cavity 
are margined each by a white, capillary, convolut- 
ed cord. It is attached to the lamellae by a thin, 
mesentery-like membrane. These cords are the 
testicles. Between the spermatic lamellae are oth- 
ers similarly arranged, which are the ovarian, on 
This is especially true of Hydra, where in the 
lates 
of Al idt , Johnst. (Halo- 
dactylus diaphanus of Farre), is quite remarka- 
ble; for he found them wanting in the isolated in- 
dividuals, but scattered here and there, in the form 
of small round sacs, in the fleshy substance of the 
corallum —some being ovaries, others testicles. 
But he is in doubt. whether or not their contents 
are emptied into the cavity of the body or upon the 
outer surfaces (Beitr. loc. cit. p. 46).* 
1 See, for Alcyonelia stagnorum, Meyen (Isis 
1828, p. 1228). 
2 Rathké has often found spawn in the stom 
ach of Actinia (Reise Bemerk. aus Taurien, zur 
Morph. 1837, p. 10, and Beitr.*zur vergleich. 
Anat. u. Physiol. in the neuesten Schrift. d. na- 
i Gesellsch. zu Danzig, III. Hft. IV. 1842, p. 
which are situated the ovaries. With the Zoanthi- 
dae the relations are of the same general nature; 
but with the Tubipora, Dana found six spermatic 
to two ovarian lamellae, See Dana, loc. cit. p. 43, . 
pl. XXX. fig. 3, b, c, d, e, f, and pl. LIX. fig. 1,b- 
—Eb. 
