ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
579 
by breeding on cooked potato. The success is quite subordinated to 
the quality of the potato and to the constant impregnation of the nutri- 
tive medium with glycerinated water. By means of the foregoing, 
homogeneous cultures in glycerin-bouillon were obtained. -Any of 
these cultures at any period of their growth contain mobile organisms. 
Such bacilli are isolated, rarely in groups, are straight or slightly curved, 
a little larger than the bacilli found in sputum, and give the charac- 
teristic colour reaction. The immobility of the tubercle bacillus is 
therefore not a constant characteristic of this organism. 
Aerobism of the Tetanus Bacillus.* — Dr. J. Ferran supports the 
view upheld by Grixoni with regard to the tetanus bacillus. Grixoni 
contended that this bacillus is an essential aerobe and only occasionally 
an anaerobe, that it thrives in the upper layers of the earth and is non- 
virulent, and that its pathogenic properties are acquired by association 
with other bacilli under conditions not accurately known. 
Ferran states that by making a series of cultures of the tetanus 
bacillus it may be shown that this presumed essential anaerobe is 
really an aerobe. The first cultures are made in an atmosphere of 
acetylen gas ; and this, in the succeeding ones, is more and more diluted 
with air until the bacillus lives entirely in air, forming thick tufts on 
the surface of the bouillon, and having undergone no morphological 
change. Only the first cultures, however, are virulent. The author 
therefore concludes that the common conception, viz. that the tetanus 
bacillus is a strictly anaerobic organism, is erroneous. 
Bacillus Gangrsense Pulpae.f — Prof. J. Arkovy describes a poly- 
morphic organism, B. gangrsense pulpse , which he considers to be the 
main cause of pulp-gangrene and of chronic alveolar abscess. The 
material was first inoculated in bouillon, and then transferred to gelatin 
and agar plates. On the former the organism grew as a bacillus, on the 
latter at first as a bacillus, but in about ten days a coccus form appeared. 
From the gelatin plate-cultures, stick subcultures in gelatin and agar 
were made. In the gelatin a bacillus grew ; in the agar, after about ten 
days a coccus appeared. When the last was transferred to gelatin plates, 
the organism reverted to the bacillus form. The results were quite 
similar when subcultures were made from the first agar plates. 
The bacillus was found in the mouth, teeth, saliva, and in gangre- 
nous tissue. It is about 4 fx long, with sharply cut-off ends. It may 
occur singly, or in short chains. It has a fish-like movement, and 
occasionally forms spores. It is easily stained by Gram’s method, but 
not with metliylen-blue. The colonies on gelatin are at first white, then 
yellow, and exhale a stinking cheese-like odour. The gelatin is liquefied 
with a strong alkaline reaction. It grows well on agar, potato, and serum, 
but best on tooth pulp. It is a potential anaerobe, and its optimum 
temperature is 37° *5-39° *5 C. Cultures inoculated on healthy teeth 
reduced the teeth to a carious condition in two months. 
Growth of Bacteria on Media made from Animal Organs.}: — Dr. 
L. E. Livingood finds that there are substances in all organs of animals 
* Centralbl. Bakt. u. Par., l te Abt., xxiv. (1898) pp. 28-9. 
f Op. cit., xxiii. (1898) pp. 917-29, 962-74 (1 pi and 12 figs.). 
X Tom. cit., pp. 9S0-4, 1002-7, 1013-54. 
1898 2 R 
