ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
199 
The second or Acrogenes group contains B. aerogenes Escherich, 
_Z>. Pfeiffer, and B. capsulatus Kruse. The colonies are whitish from the 
first. Even in the animal body the capsules are hard to stain, and there 
are no pseudo-capsules in artificial cultures. With all three kinds of 
sugar there is copious and constant gas formation. Acid is formed in 
all three kinds of sugar-bouillon. Milk is rapidly coagulated. 
Bacillus coli capsulatus.* — Dr. L. Jenner describes an organism 
which is remarkable for its pathogenic properties when possessing a 
capsule ; but when the capsule is absent it is little or not at all viru- 
lent. B. coli capsulatus is a rodlet with rounded ends, of variable 
length, but usually short. It grows well on various media. It does 
not liquefy gelatin. It develops gas in gelatin shake cultures, and cn 
saccharated media. It coagulates milk, forms indol, and produces acid. 
It stains with anilin dyes, but not by Gram’s method. The capsules are 
demonstrable by staining first with phenol-fuchsin, and afterwards with 
aqueous gentian-violet ; by this method the body of the bacterium is 
stained red and the edge of the capsule violet. A non-capsulated form 
of the organism is obtained from cultures of old smears on gelatin, 
by inoculating the latter in pepton water, and incubating the tubes 
at 37° for 21 to 48 hours, and making secondary gelatin smears from 
them. 
The results obtained from inoculating animals with capsuled and 
non-capsuled cultures are strikingly different. The capsuled forms are 
fatal to white mice in a few hours, while the non-capsuled variety is 
little if at all fatal. It would, therefore, seem that the capsules are to 
be regarded as protective. 
Colonies of the capsuled form are sharply delimited ; when the 
growth is mixed, i.e. containing more or less of the non-capsuled 
variety, the margins of the colonies become more or less irregular and 
crenated. 
Pathology of Venous Thrombosis.f — Dr. M. Jakowski shows that 
the natural toxins, freshly produced by bacteria, introduced into the 
blood current, are far more powerful exciting causes of venous throm- 
bosis than the artificial toxins, made from cultures of the same bacterium, 
injected into the circulation. The experiments were made on guinea- 
pigs, with B. coli com. and its toxins. 
Diplococcus niagnus.J — Dr. A. G. Rosenthal, in a preliminary ac- 
count, gives a description of a coccus, Diplococcus magnus, found in the 
air. It is of large size, has a distinct capsule, is almost invariably in 
pairs, and is kidney-shaped. It does not stain by Gram’s method. It 
was cultivated on the usual media, and grew best at 37° C. 
Resistance of Diplocfe* sus lanceolatus to Drying. § — According to 
Dr. D. Ottolenghi, Diplococcus lanceolatus retains its virulence in dried 
sputum for more than 70 days, while its vitality may persist even after 
its virulence has been extinguished. 
* Journ. Pathol, and Bacteriol., v. (1898) pp. 257-G1 (1 pi.), 
t Centralbl. Bakt. u. Par., l te Abt., xxv. (1899) pp. 10-12, 58-64. 
x Tom. cit., pp. 1-4 (3 figs.). § Tom. cit., pp. 120-1. 
