236 Miscellaneous. 
On the Contractile Tissue of Sponges. By N. Lizrperxtun. 
In a recent supplement to his numerous investigations of Sponges, 
Lieberkiihn has paid special attention to the ciliated embryos of the 
Spongille. The ova present a perfectly regular segmentation. They 
are situated, like the embryos, in lacune of the parenchyma of the 
body. It is there also that the spermatic cells are found. To ob- 
serve the embryos, Lieberkiihn divides the Spongilla into thin sec- 
tions, which he leaves to soak in water for a day. The embryos up 
to the moment when they commence their independent life remain in 
the envelope formed by the contractile tissue of the sponge, in which 
they turn about by means of their ciliary coat. During this period 
the cavity of the body, which is filled with liquid, is formed. A 
portion of the spheres of segmentation which have not undergone 
much modification are crowded together in the posterior part of the 
body, where they form an opaque mass. The cilia of the embryo 
are very long, and implanted upon still amorphous sarcode, and not 
upon true cells. The mass of the embryo properly so called, 
however, is formed by contractile and nucleated cells, a portion of 
which enclose siliceous spicules in their interior. This tissue is iden- 
tical with the contractile parenchyma of the sponge itself. — Archiv 
fir Anat. und Physiol. 1867, p.509; Brbl. Univ. 1868, Bull. Sei. 
p. 168. 
Comparative Investigation of the Generative Organs of the Hare, 
Rabbit, and Leporide. By 8. Antone. 
The author gives an account of the anatomy of the generative 
organs in the Leporides produced by the union of a male and female 
hybrid between a male hare and female rabbit. 
In certain organs, such as the feet and the ovaries, the Leporide 
occupies a middle place between the hare and the rabbit. The 
generative organs are complete in both sexes. In the female the 
ovaries resemble those of the hare in colour and texture, and those 
of the rabbit in the volume and dissemination of the Graafian vesi- 
cles. The vagina and vulva, on the other hand, resemble those of 
the rabbit in their dimensions, the position of the meatus urinarius, 
and the extent and arrangement of the canal of Gaertner. The 
fecundity of these hybrids is shown by their anatomy : the females 
possess many ovules, and the testes of the males furnish a liquid 
filled with spermatozoids. In the mule, Brugnone is the only ob- 
server who has detected spermatozoids. 
The author concludes with the following summary of results :-— 
1. The female hybrid of the hare and rabbit can be fecundated 
by the male hybrid. 
2. These hybrids, whilst presenting intermediate characters, pos- 
sess genital organs which much more resemble those of the rabbit 
than those of the hare.—Comptes Rendus, June 22, 1868, pp. 1267— 
1269. 
