114 EXPERIMENT STATION RECORD. 



normally in air, but under water almost none at all. The authors believe that the 

 results obtained in these experiments demonstrate that nitrogen assimilation takes 

 place within the root tubercles and not in the leaves. 



Further observations on Nitragin and on the nature and functions of the 

 nodules of leguminous plants, M. Dawsox {Proc. Roy. Soc. [London], 66 {1900), 

 Xo. 435, pp. 63-63). 



A new departure in cytology {Xature, 61 {1900), Xo. 1582, pp.385-3S7). — A 

 review of a recent work by A. Fischer, of Leipsic. 



FERMENTATION— BACTERIOLOGY. 



Variability in the power of liquefying gelatin possessed by 

 bacteria, H. W. Conn {CentU. Bald. a. Par., J. Aht., 5 {1899), ^^o. 

 20^ pp. 665-669). — On examining specimens of milk from a neighboring- 

 dairy, the author discovered 2 rather constant organisms in his cul- 

 tures. The lirst was a Micrococcus and seemed to be almost univer- 

 sally found in all the specimens of milk. Its morphology is described 

 at some length. With it, and almost equally abundant, was found a 

 bacterium which differed from the first in having no power of liquefy- 

 ing gelatin. As experiments with the organisms were continued, it 

 was found that intermediate grades existed between the two, and after 

 continuing the experiments for several months, the author arrived at 

 the conclusion that he had one organism which showed a wide varia- 

 bility. Subsequent study of the culture proved that with the excep- 

 tion of the power of liquefying gelatin the organisms were absolutely 

 identical. 



Permanent forms of nitric and nitrous organisms, A. Beddies 

 {Chem. Zt(/., 23 (1899), JTo. 63, pp. 61^0-61^1 ; ahx. In Jour. Chem. Soc. 

 [London], 78 {1900), No. ^,6, II, p. SJf). — From manure, .sewage, etc., 

 the author prepared nutritive solutions containing about 2 gm. each of 

 organic and inorganic matter per liter. These were mixed with 1 to 



2 per cent of meat juice and the nitrogen content was raised to about 



3 per cent by the addition of ammonium sulphate. The alkalinity 

 was raised or lowered as desired hx the addition of sodium carbonate 

 or phosphoric acid, and, after sterilizing, the solutions were inoculated 

 with 0.1 to 0.2 gm. of soil containing the nitrif jdng organisms. The 

 cultures were kept in diffused light at 20 to 25° until nitrification was 

 complete (2 to 3 months). Material from these cultures was used for 

 inoculating sterilized solutions containing 1 per cent of a cold water 

 extract of a soil rich in humus and 0.25 per cent of water glass. 



By this means nitrifying organisms were obtained which were less 

 sensitive than those obtained b}^ Winogradsk}^ in inorganic media. 

 Four stable forms of nitric and 3 of nitrous bacteria were isolated. 

 One of the nitric forms was capable of resisting the action of steam at 

 100° for 2 minutes, and one of the nitrous bacteria lived for 1 minute 

 in steam at the same temperature. The other two nitrous bacteria 

 could not withstand steam, but survived for several minutes in a dry 



