238 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
considerable numbers ; and on microscopical examination discovered a 
bacillus to which the mortality was due. This organism ( Bacillus ento- 
motoxicon) occurs in the blood and tissues of the insect. It is 1 • 2-1 • 8 ^ 
long by 0 • 6-0 • 8 /x broad ; it is motile, does not form spores, and stains 
well with most anilin dyes. It is aerobic, and potentially anaerobic. 
The colonies on agar are white, with fanlike radiations. Gelatin is 
liquefied. Milk is rapidly coagulated, with a highly offensive odour. 
It grows well at room temperature, and is killed by exposure to high 
temperatures. The infected insect becomes sluggish, swells, and after 
death rapidly liquefies. The toxin is lethal to many species of insect. 
The disease is easily communicated to healthy squash-bugs by contact 
with the fluids of infected insects, or with agar cultures. The young 
insects are easily infected, the older ones being more resistant, and the 
larvae apparently quite refractory. 
Leptothrix placoides.* * * § — Dr. A. R. v. Dobrzyniecki describes a species 
of Leptothrix ( L . placoides) which was isolated from an old tooth stop- 
ping. It consists of long delicate structureless threads, which, when 
stained, seem to be made up of chains of rodlets, and in which spore-like 
bodies were observed. The Leptothrix-iodine reaction (iodopotassic 
iodide acidulated with lactic acid) was successful. The organism was cul 
livable on agar, blood-serum, and gelatin, the latter being liquefied, but 
not in bouillon or on potato. The colonies are white, firm, and discoid. 
Ciadothrix odorifera.f — Herr Rullmann regards this organism, to 
which the odour of freshly turned-up soil is largely due, as a variety of 
(7. dichotoma. 
Silkworm Microbe.* — Sig. L. Macchiati gives reasons for identify- 
ing the microbe which has been named Streptococcus Pastorianus, the 
cause of the flaccid condition of silkworms, with the earlier described 
S. Bombycis. 
Rejuvenescence of Effete Pebrine Corpuscles.§ — It is well known, 
says M. M. Krassilschtchik, that pebrine corpuscles, when old, lose the 
power of exciting the disease in silkworms. Their activity and virulence 
may, however, be restored if they are swallowed by the common sparrow. 
Infected moths kept over from the preceding year are pounded up in a 
mortar with a little water. Pieces of bread soaked with tbe mixture 
are given to sparrows. On the third day the excrement is found to con- 
tain active pebrine germs. Silkworms fed on mulberry leaves contami- 
nated with the fresh excrement acquire pebrine. On the other hand, 
dried excrement does not excite pebrine ( Microsporidium ), but sets up 
flacherie ( Streptococcus Pastorianus) and grasserie ( Micrococcus larda- 
rius ), or even a mixed infection of the tw r o diseases. 
It would seem therefore that birds contribute to the propagation of 
pebrine, their intervention being indispensable for rejuvenating inactive 
corpuscles. Some of the sparrows fed on the infected moths died, the 
control birds remaining quite healthy. 
* Centralbl. Bakt. u. Par., l te Abt., xxi. (1897) pp. 225-9 (4 figs.). 
t Op. cit., 2 1e Abt., ii. (1896) pp. 116-7. 
% Bull. Soc. Bot. Ital., 1896, pp. 292-7. 
§ Comptes Rendus, cxxiii. (1896) pp. 358-9. 
