ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
185 
Larvae of Velella.* — M. M. Bedot has studied the young stages of 
a Velella which he found in abundance at Nice. His investigations, 
whilst raising questions which can only be solved by study of more com- 
plete material, seem to dispose of the hypothesis which is generally 
accepted that the pneumatophore is formed by invagination of the 
ectoderm. 
Minute Structure of Hydra.j — Dr. R. Zoja has used Ehrlich’s me- 
thylen-blue method in studying Hydra ( H . viridis and H. grisea ), and 
finds that the stain demonstrates what look like nervous elements, much 
more complicated and abundant than was hitherto supposed. Thus 
there are numerous nodules from which fibrils diverge in all directions, 
and other elements like ganglion-cells, with a rich array of prolonga- 
tions. Five forms of cell are described. He believes that these ele- 
ments are nervous, for they stain specifically with methylen-blue, they 
are connected with the cnidoblast and myo-epithelial cells, and some of 
the cells resemble ganglion cells. 
Porifera. 
New Genus of Heteroccelous Calcareous Sponges.f — Dr. R. 
Hanitsch has a note on a new Portuguese sponge (. Amphiute n. g.) which 
combines the characters of Ute and TJtella. The flagellate chambers are 
narrow and radially disposed; there are large longitudinally disposed 
rod-spicules on the dermal and gastral surfaces. He only knows as yet 
of one species, A. Paulini. 
Protozoa. 
Fresh-water Rhizopods.§ — M. F. Le Dantec has made a comparative 
study of Amoeba proteus and Gromia fluviatilis. The latter gives off a 
very rich plexus of anastomosed pseudopodia which adhere to the surface 
of solid bodies. These bodies are gradually surrounded by the proto- 
plasm of the Gromia , and slowly brought into the interior of the test. 
There is no vacuole around these foreign bodies, which are thus from the 
first in direct contact with the protoplasm. If a non-nucleated mass 
freshly separated from a Gromia be met by the pseudopodia of the parent 
mass fusion immediately occurs, and almost at once all trace of the 
separation disappears. If, on the other hand, the pseudopodia of the 
Gromia should meet with a morsel of protoplasm which has begun to 
undergo degeneration, the contents of this sphere run into the pseudo- 
podium. The author explains these facts as phenomena of nutrition. The 
first consists in the addition to a mass of protoplasm of another mass of 
identical composition. The second phenomenon recalls the passage of 
the protoplasm of an Infusorian into that of an Acineta. In all the 
preceding cases there has been no question of digestion, although the 
protoplasm is able to dissolve certain substances which bathe in its 
interior. Starch-grains, for example, are profoundly modified. If proto- 
plasm be considered as a very special medium necessary to the life of a 
nucleus we may say that the protoplasmic medium is very little differen- 
tiated, and very little separated from the external medium in Gromia . 
* Rev. Suisse Zool., ii. (1894) pp. 463-6 (1 pi.). 
t Rend. R. 1st. Lombard, xxv. (1892, received 1895), pp. 700-12 (1 pb). 
I Zool. Anzeig., xvii. (1891) p. 433. 
§ Comptes Rendus, cix. (1894) pp. 1279-82. 
