640 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
fying organisms must be employed for its isolation. On plates the deep 
colonies are brownish ; the superficial are highly refracting droplets. 
On nitrite-agar the growth consists of a deposit of colourless droplets. 
The microbe is best stained with carbol-fuchsin, and is then seen as a 
small homogeneous rodlet with pointed ends. It is endowed with a 
sheath or capsule, and measures 0 • 6-0 • 8 by 1-1 • 5 fx. There are other 
morphological forms, the most prominent being the filament, which 
may exhibit true branching. As already stated, the microbe will not 
develope in ordinary substrata, and it appears to be extremely sensitive 
to ingredients commonly used in nutrient media. It does not pick up 
free nitrogen, but can make use of atmospheric carbonic acid. Another 
characteristic is that it is extremely sensitive to free acids, in which 
it differs from most Hyphomycetes. Hence it differs morphologically 
from Schizomycetes and physiologically from Hyphomycetes. For the 
composition of the numerous cultivation media the original should be 
consulted. 
Morphology of Bacillus Mallei.* — Prof. B. Galli-Valerio made ob- 
servations which confirm the fact that in cultures of Bacillus Mallei there 
may be found filamentous forms 16—80 \x long, real and false branched 
forms, and forms often ending in club-shaped extremities. These forms, 
which are especially frequent in pepton-bouillon cultures, bring B. Mallei 
into proximity with Streptothrix , forming together a group between 
Hyphomycetes and Schizomycetes. 
On other media, such as potato, carrot, gelatin-serum, agar, the ele- 
ments were less filamentous and shorter. 
The filamentous forms were not observed in the lesions of inoculated 
guinea-pigs, and in the peritoneum of the frog all the forms were 
extremely small. 
Micrococcus tetragenus.f — MM. Bose and L. Galavielle obtained 
their material from gangrenous pneumonia in a man. They found that 
the organism was easily cultivable on the ordinary media. It requires 
oxygen, and its optimum temperature is 37°-38°. In alkaline media it 
developes luxuriantly, but scantily in acid. It is polymorphic, and 
forms varying from a single coccus to zoogloea heaps are met with. It 
is pathogenic to guinea-pigs, mice, and rabbits, and to some extent to 
pigeons. It has no effect on fishes or frogs. Snbcutaneous injections 
caused abscesses. Filtered cultures produced toxic phenomena, the in- 
tensity of which varied with the quantity injected and with the animal. 
Immunisation experiments were mostly negative. 
Bacillus pseudo-tuberculosis.j: — Dr. E. Klein states that he has pro- 
duced a pseudo-tuberculosis in guinea-pigs and rabbits by injecting them 
with sewage-infected river water. From the necrotic foci in the lym- 
phatic glands, liver, spleen, and lungs, pure cultures were obtained. To 
the morphological and biological characters given by A. Pfeiffer (1889) 
and by Preisz (1894) the author adds that the pseudo-tubercle bacillus is 
an alkali-former ; it does not produce indol ; on blood-serum it grows 
* Centralbl. Bakt. u. Par., l le Abt., xxvi. (1899) pp. 177-80 (5 figs.). 
t Arch. Med. Exper. et d’Anat. Pathol., xi. (1899) p. 70. See Centralbl. Bakt. 
u. Par., l te Abt., xxvi. (1899) pp. 270-5. 
X Centralbl. Bakt. u. Par., l te Abt., xxvi. (1899) pp. 260-1. 
