ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
87 
systematically. In the remainder, except the last, marine, fresh-water, 
and fossil species are photographed belonging to special geographical 
areas, the Baltic, the Mediterranean, New Zealand, Japan, Mexico, 
Barbadoes, Brazil, Hungary, Bolivia, &c., or from diatomaceous earths 
or deposits. Plate 59 is a “ show-plate ” of some of the more beautiful 
diatoms arranged in patterns. 
3 . Schizomycetes. 
Chemical and Physiological Researches on the Secretions of 
Microbes.* * * § — MM. A. Arnaud and A. Charrin describe the elimina- 
tion of the carbon and nitrogen in the transformation of asparagin under 
the influence of Bacillus pyocyaneus. In a culture of the bacillus con- 
taining 1-6 grm. of asparagin, after fifteen days 1*16 grin., or 72 • 5 per 
cent., was eliminated as C0 2 , and '221 mgrm., or 13' 8 per cent., was 
found to be present in the protoplasm of the microbe. In the case of 
the culture of the bacillus in a gelatin solution, the nitrogen eliminated 
as ammonia was found to be 70 per cent., while in a culture of asparagin 
91 per cent, was found to have been eliminated. 
Osmotic Experiments on Living Bacteria. j — M. A. Wladimiroff 
gives the details of experiments undertaken with living bacteria and 
various salt solutions. The method adopted was to examine the move- 
ments of the bacteria in a drop of salt solution and meat broth hanging 
from the cover-glass of a suitable microscopic slide, and to observe at 
what concentration there remained a few bacteria which retained the 
ability to swim slowly, and in what slightly stronger solution the last 
swimming bacterium had vanished. A table giving the “ limiting solu- 
tion ” which is the mean of these concentrations for six bacteria, and 
ten salts, is appended to the paper. 
New Comma Bacillus.J — Hr. T. Smith isolated from the large in- 
testine of swine a comma bacillus which differs from those usually 
described in not liquefying gelatin. Cultivations were successfully 
made in gelatin and agar, wherein superficial and deep colonies appeared, 
the former being flat and circular and attaining a diameter of 3-5 mm., 
while the latter were more spheroidal or raspberry shaped with an 
averaged diameter of O' 5 mm. The organisms also grew well in neutral 
pepton bouillon and in hanging drops. Lively movements were visible. 
The predominating form was that of a comma, but there were also spirilla 
of one and a half to two, and occasionally of ten turns. This vibrio 
was found to be strictly aerobic, and to possess no fermentative action 
on sugar. Milk remained unchanged. On potatoes a thin yellowish 
encrustment appeared in a few days. The flagella were easily stained 
by Loeffler’s method, though an addition of acid to the ferrotannate 
solution was unnecessary. The vibrio did not appear to have any 
pathogenic action. 
Fish-poisoning.§ — Dr. M. Arustamoff describes a series of eleven 
cases of fish-poisoning which occurred under his observation at Astrakhan. 
* Comptes Rendus, cxii. (1891) pp. 1157-60. Cf. this Journal, 1890, p. 83. 
t Zeit. Physikal. Cbem., vii pp. 529-43. See Journ. Chem. Soc., 1891, Abstr., 
p. 1131. t Centralbl. f. Bakteriol. n. Parasitenk., x. (1891) pp. 179-80. 
§ Tom. cit., pp. 113 -9. 
