94 
Miscellaneous. 
the male sex appearing before the female, in proportion as the species 
degenerates by sexual reproduction. 
The spores proceeding from the fecundation of the oospheres by 
the antherozoids fall to the bottom of the water, and remain in a 
stationary condition for a considerable time. Cohn, who has lately 
published an important memoir*' on the monoecious Volvox globator, 
thinks that these spores need to be dried before germinating, but he 
was unable to observe this germination. Cienkowski has seen the 
contents of the sporo divide, and he thinks that each sphere of seg¬ 
mentation ultimately becomes a coenobium. 
I was fortunate enough at the beginning of June to trace the 
development of tho spores of the species of Volvox which I had 
previously studied. I have ascertained that, contrary to Cohn’s 
opinion, the spores of Volvox pass the winter in the water. In 
fact those which I observed were collected in the mud of a toler¬ 
ably deep basin in the Jardin des Plantes which was constantly filled 
with water. 
These spores, of an orange-yellow colour, possess two enveloping 
membranes—an exospore with double outline and a delicate endo- 
sporo. At the moment of germination the exospore is ruptured, 
and the swelled endospore is seen to project through tho torn place. 
At the same time tho contents of the spore, separated from the en¬ 
dospore by a clear space, divide into two equal parts, which, by 
successive bipartitions, give origin to four, eight, sixteen, &c. small 
cells. The cells, which are at first orange-yellow, acquire a brown 
tint, becoming more and more greenish in proportion as the work of 
division advances. When the segmentation of the spore is com¬ 
pleted, the cells form a spherical layer analogous to the blastoderm 
of a holoblastic ovum. Each element afterwards acquires two 
vibratile cilia. The endospore disappears, and the young Volvox, 
thus constituted, moves freely in the water. The cells, which are 
at first very close together, separate from each other by the inter¬ 
vention of a gelatinous substance. 
An interesting fact is the presence, among the vegetativo cells of 
the Volvox while still contained in the endospore, of elements larger 
than the others, which will subsequently give origin to the daughter 
colonies by a mode of division analogous to that observed in the 
spore. 
The spores of Volvox therefore germinate in water, and each of 
them produces a single colony by an operation of segmentation 
identical with that which gives origin to a daughter colony at the 
expense of a cell of tho mother colony.— Bull. Soc. Philomath. 
Paris, July 27, 1878. 
On the Anatomy of the Larva of Eristalis tenax. By Dr. Batelli. 
Dr. Batelli has communicated to the Tuscan Society of Natural 
Sciences a memoir on the structure of the well-known “ rat-tailed ” 
larva of Eristalis tenax. He regards the external tube of the tail 
* Beitrage zur Biologie der Pflanzen, 1875. 
