426 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Influence of Soil Microbes on Vegetation.* — M. E. Gain has in- 
vestigated the properties of alinite, with a view to ascertain if its 
application produced a marked increase in the weight of plants under 
experimental conditions, and if so, whether this favourable influence 
exists to any useful degree under ordinary conditions of cultivation. 
Alinite is a dry yellowish powder which contains the spores of Bacillus 
Bllenbachensis a, now regarded as identical with B. megaterium de 
Bary. This microbe has the power not only of fixing free nitrogen, but 
of dissolviug out nitrogen from organic matter. Moreover, the pentoses 
form a food-stuff extremely favourable to its'development. 
Though the number of experiments is too scanty to make a decidedly 
definite statement, the results obtained by the author under experimental 
conditions, that is to say, under favourable conditions of soil, temperature, 
humidity, and attention, gave sufficient encouragement to pursue the 
research under practical agricultural conditions. The experiments were 
made with buckwheat and flax. The conclusions arrived at were that 
alinite does exert a useful action, and that this is shown by the greater 
development of the plants and by a more abundant grain production. 
Chemical and Bacteriological Examination of Soils. t — Dr. A. C. 
Houston’s report deals with the chemical and bacteriological examination 
of soils with reference to the amount and nature of the organic matter, 
and the number and character of the bacteria contained in them. The 
intention of the inquiry was to examine pari passu chemically and 
bacteriologically the washings from surface soils, and more particularly 
those soils suspected of being in dangerous proximity to water supplies. 
The results of bacteriological examination appear to have been more 
successful in demonstrating the existence of pollution than the chemical. 
The report contains the results of numerous experiments and descriptions 
of many organisms. 
Sugar Bacterium.j: — Profs. H. M. Ward and J. B. Green report 
exhaustively on a sugar bacterium derived originally from excrescences 
on Madagascar sugar-canes, these clumps being produced by the sym- 
biotic action of the bacillus with a yeast. The organisms were separated 
and isolated on sugar-gelatin. On plates the colonies of the bacterium 
were dome-shaped, watery -looking, and stiff enough to be lifted on the 
needle. The colony, in fact, is a zooglcea mass composed of short rodlets 
in pairs or chains, the cell-walls of which are so swollen as to furnish 
the zoogloea jelly. The average size of the rodlets is 2-3 p. by 1 p.. 
The organism appears to grow equally well in the presence or absence 
of air, but refuses to grow in or on any pabulum devoid of sugar. The 
best results were obtained with cane-sugar, either in a purified or in a 
raw condition. In 10 per cent, saccharin and yeast extract at 16°— 31° C., 
the liquid became opalescent and viscous in two or three days, typical 
gelatinous zoogloea being deposited. The viscosity is thought to depend 
on the deliquescence oi the swollen cell- walls. Special experiments 
determined that the bacterium produced acetic and succinic acids and 
carbonic dioxide. The immediate antecedent of the acetic acid appears 
* Rev. Ge'n. de Bot. (Bonnier), xi. (1899) pp. 18-28. 
+ Rep. Local Govt. Board, 1897-8, pp. 250-307 (13 fig'.). 
X Pioc. Roy. Soc., lxv. (1899) pp. 65-84. 
