ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
339 
larva, and are turned inwards in the metamorphosis. Tho whole meta- 
morphosis comprises four stages : — (1) The transition stage, with larval 
tissue in the middle, a broad amoeboid margin, and transitional tissuo 
between ; (2) the flattened stage, with modified larval tissue turned 
towards the margin, which is now narrower (period an hour after fixing) ; 
(3) retraction of the amoeboid margin and assumption of definite contour 
(1-2 days); (4) acquisition of final form, arrangement of spicules in 
strands, and formation of osculum (third day). 
Development of Ephydatia from the Gemmules.* — Herr W. Zykoff 
placed gemmules of Ephydatia Mulleri Liebk., which had been dry for 
almost two years, in an aquarium, and in fifteen days the embryos began 
to creep out. Each was a somewhat compact clump of amoeboid cells, 
enclosing a mass of yolk-substance, but forming an external layer of flat 
ectoderm cells with pseudopodia. The young organism becomes a little 
plate, with the gemmule shell near its middle. By the second day spicules 
appear, and canals arise as clefts in the mesodermic parenchyma. These 
become lined by very flat endoderm cells. By the second or third day 
an osculum is formed, before there are any ciliated chambers, and it is 
suggested that this is formed almost mechanically by the pressure of 
the internal water. On the third day the number of parenchyma 
(mesoderm) cells increases ; the yolk-substance decreases ; the number of 
spicules increases, and they grow ; the canals branch ; and the ciliated 
chambers begin to appear, apparently as cavities within clumps of 
parenchyma-cells, which subsequently communicate with the cavities 
of the canals. The fact of most interest is, perhaps, the most general 
one that the original mesoderm elements differentiate into ectoderm and 
endoderm. But one cannot help doubting whether these names mean 
very much in such a case. 
New Sponges from the Mediterranean.! — M. E. Topsent, who has 
been working at the rich Sponge-fauna of Banyuls, gives diagnoses of 
forty new species of Sponges ; some of these are representatives of new 
genera, of which Sanidastrella is a Tetractinellid ; and Baphisia, Leptosia , 
Acheliderma , Hymerhabdia, and Holoxea Monaxonids. The distribution 
of some Sponges is shown to be very wide. 
Protozoa, 
Infusoria in Sputum from Pulmonary Gangrene.!— Dr. Streng has 
observed Infusoria in two cases of pulmonary gangrene. They were 
found in the yellow foetid sputum, together with masses of bacteria. 
They are described as oval, apparently structureless cells about the size 
of white blood-corpuscles, endowed with very lively movements. At 
one end were several flagella, and the cells seemed able to alter their 
shape. On agar, gelatin, and blood-serum they did not increase, but in 
bouillon at incubation temperature they were present in large numbers 
for 4-5 days. By the tenth or eleventh day they were dead and gone. 
The method suggested by Kannenberg for staining Infusoria with 
aqueous methyl-violet and examining in saturated acetate of potash w^as 
* Biol. Centralbl., xii. (1892) pp. 713-0. 
t Arch. Zool. Exper. et Gen , x. (1892) pp. xvii.-xxviii. 
% Fortschr. d. Med., x. (1892) No. 19. See Centralbl. f. Baktcriol. u Paraisitenk., 
xii. (1892) pp. 763-1. 
