456 SUMMARY OF CURRENT RESEARCHES RELATING TO 



of a pathogenic group of bacilli of the Hog Cholera or Bacillus enteritidis 

 Gaertner type, intermediate between the typhoid and colon groups. The 

 members of this intermediate group possess the morphological and 

 motile properties of Eberth's bacillus, but differ therefrom chiefly in the 

 fermentation reactions, since they produce gas in the presence of glucose 

 and other more easily fermentable carbohydrates. Their chief distin- 

 guishing feature from tbe bacillus of Eschericb, on tbe other hand, rests 

 upon the fact that fermentation in various media made from milk does 

 not produce sufficient acidity to precipitate the casein, but on the con- 

 trary, the acid production is but a transient process, and is followed, in 

 the presence of air, by a prompt (2-3 days) and distinguishing alka- 

 linisation of the media, which furnishes a ready means of differentiation 

 from both the typhoid and the colon types. Though the subdivision into 

 these three closely- allied groups was made by Durham in 1898, the 

 author's paper is extremely valuable, as it not only summarises fully 

 what is already known, but adds further information and also particulars 

 relative to a new organism, Bacillus 0. The paper is well illustrated. 



Growth of the Typhoid Bacillus in Soil.*— Dr. S. Martin's recent 

 investigations on this subject show that certain cultivated soils, especially 

 garden soils, when sterilised, are favourable to the vitality and growth 

 of the typhoid bacillus. Virgin or uncultivated soils are unfavourable. 

 When the typhoid bacillus is added to unsterilised soils, kept very 

 moist, and at a temperature of about 19°-37°, it cannot be recovered. 

 If, however, the soil be less moist or dry, and at a temperature of 

 2°-12°, the bacillus may be recovered up to twelve days. The reason 

 of the disappearance of the bacillus from unsterilised soils appears to 

 be the antagonism of some of the soil microbes to its growth ; and 

 there is some evidence to show that the disappearance has been pari 

 passu with an increase in the number of putrefactive bacteria. As far as 

 is known, the typhoid bacillus has no resting stage. It has no spores ; 

 so that if it once die it cannot be expected to reappear unless a fresh 

 inoculation occur. 



Variability of the Agglutinative Aptitude of the Typhoid 

 Bacillus.f — E. Sacquepee finds that the agglutinative aptitude of B. ty- 

 phosus is variable ; being sometimes more, sometimes less agglutinable 

 than the typical bacillus. The variations in excess are slight and tran- 

 sitory, those in defect are more important and arc of frequent occurrence 

 under natural conditions. The latter, while answering in other respects 

 exactly to the classical type, are little or not at all agglutinated by 

 typhoid serum, but when preserved in closed tubes spontaneously assume 

 the typical function. On the other hand, the typical typhoid bacillus, 

 if long in contact with an immunised organism, becomes less and less 

 agglutinated by the serum. From this the author concludes that the 

 typhoid-like forms are variants of B. typhosus modified by a long sojourn 

 in an infected or immunised organism. They have become modified by 

 getting accustomed to their environment. 



Accumulation Experiments with Bacteria Decomposing Carba- 

 mide. | — Prof. M. W. Beijerinck describes investigations the object of 



* Local Gov. Board Kep. 1899-1900 (1901) pp. 525-48. 

 t Ann. Inst. Pasteur, xv. (1901) pp. 249-60. 



J Centralbl. Bakt., 2 t0 Abt., vii. (1901) pp. 33-61 (1 pi. and 4 figs.). See Journ. 

 Chem. Soc., lxxx. (1901) Abstr. ii. p. 264. 



