ACALEPH^. 
333 
number of pouches in their grasping-arms, for the reception of the eggs 
and brood, which the males want entirely. The band-stripes, situated in 
the folds, which Ehrenberg considered as pouches, contain the female 
egg-germs imbedded in the parenchyma, to which exit is given by the 
dehiscence of its outer covering of epithelium. In the male these bands 
contain an innumerable multitude of small, thick-walled, testicular sacs, 
which discharge on the surface of the band turned to the branchial cavity, 
and in which spermatozoa are developed from the cells, according to 
known physiological laws. When Ehrenberg thought he recognised un- 
developed eggs between masses of spermatozoa, in the sexual apparatus 
of the Medusce, they were evidently the above-mentioned cells, in which 
the spermatozoa had not yet developed themselves. The reporter would 
here especially give warning, that every thing resembling an egg-germ 
should not be held for an egg. By the discovery of the cellular de- 
velopment, Schwann has solved for us the enigma, that the contents of a 
testis may completely resemble those of an ovary. Ehrenberg has also 
made some observations on the stinging-organs of Cyanea capillata. 
He found them only on the fang-threads of this animal, which it could 
elongate to twenty-five feet. Their construction is quite like those of 
the Hydroe, only wanting the hooks. 
The correctness of the reporter’s description of the first stages of 
development of the Medusa aurita has been confirmed by Sars, in an 
excellent treatise on the development of that animal and Cyanea capil- 
lata ; and Sars has also proved, that the animal described by him as 
Strobila, is only a young state of the same Medusa. Steenstrup quotes 
this remarkable metamorphosis of the Med. aurita as an example of 
that phenomenon, styled by him “ Generationswechsel” (transmutable 
generation) ; and he considers the polype-like individuals, out of which, 
by transverse section, a number of disc-shaped young Medusae proceed, 
as the nurses of these young ones. 
According to the observations of Philippi, Physophora tetrasticha is 
not a compound animal (Fror. N. Notiz, Bd. 22, p. 344, and Bd. 23, p. 
88). The cavity at the end of the axis of this animal is neither filled 
with air nor provided with an opening; neither are the swimming- 
bladders filled with air ; and the fang-arms are neither giUs nor holders 
of fluid; the stomach is not in connection with the hollow axes; and 
the animal possesses organs of both sexes. 
A Stephanomia has been discovered by Milne Edwards in the Gulf 
of Villafranca, which is very nearly allied to the genus Apolemia, Esch., 
and has been called by him, on account of the spiral rolled-up rachis, 
Steph. contorta (Ann. d. Sc. Nat. t. 16, p. 217). In the upper end of 
the body of this Medusa is found a pear-shaped hollow organ, which, 
besides a reddish fluid, contains an air-bladder open beneath. The 
band-shaped spiral body has three different appendages at its margin. 
377 
