BOTAXY. 919 



nished bj' the acid radirle). The authors jjive extensive reviews of literature relat- 

 ing to this subject, and an extended bil)liotri-ai)hy of the subject comjik'tes the report. 



Formation of sodium carbonate, or black alkali, by plants, F. K. Ca.mehon 

 ( r. <S'. IJept. A(jr., Rpt. 71, pp. 01-70). — A study is reported of creosote bush ami 

 greasewood, in an attempt to show the effect of these plants in causing an accumula- 

 tion of sodium carbonate at the surface of the soil. It seems probable that the 

 neutral salts are brought up from the lower depths of soil, and through the agency 

 of tilt plant are transformed into the carbonates or black alkalis. 



Resistance to black alkali by certain plants, F. K. Cameron ( ['. S. Dejit. A'jr., 

 Rpt. 71, pp. 71-7S). — Notes are given on the resistant power f)f a nund)er of ])lants to 

 the action of black alkali. Among those described are />(W/>///(.s apinita, Siuvda Inter- 

 iiieilia, and AtripJc.r brarifo.'ia. These plants seem to be able to make a satisfactory 

 growth on soils containing relatively large amounts of soluble car])onates. This 

 growth is believed to be due in a large measure to the production and exudation of 

 considerable amounts of soluble organic acids, which are capable of decomposing the 

 carbonates and thus protecting the root crowns from the corrosive action of the 

 alkalis. 



Can leucin and tyrosin be used as plant nutrients? K. Hchl'lze {Latidn-. Verx. 

 Stat., 56 {1901), Xo. 3-3, pp. 97-106). — The author quotes the investigations of a 

 number of experimenters on the assimilability of these substances l)y ]>lants and 

 describes experiments of his own with lujnnes, vetches, and castor beans, which 

 showed that tyrosin and leucin could be used as sources of nitrogen by phanerogams. 



Org-anic nitrog'en and cultivated plants, A. Thomson {Sitzber. Naturf. GeseU. 

 Uitir. Dorpat, 12 {1899), pp. 307-322; ahs. in Ann. Agron., 27 {1901), Xo. 12, pp. 

 602-604) . — A series of experiments with oats and barley grown in water cultures 

 Avhich were given various forms of organic nitrogen is reported upon. The organic 

 compounds em])loyed were sodium urate, sodium hippurate, and urea, comparisons 

 being made with sodium nitrate. The results of the experiments show that the 

 nitrogen of urea and uric acid have the same value, as far as the grasses are con- 

 cerned, as nitric nitrogen; and the plants seem to be able to easily utilize these sul»- 

 stances. On the contrary, the nitrogen in hippuric acid is detrimental to plant growth. 



The bacteria of root tubercles of Leguminosae, P. Neumann {Landir. Yerx. 

 Stat., 56 (1901), Xo. 2-3, pp. 187-202). — A report is given of studies made with the 

 organisms taken from the tubercles of the roots of T7cia faha. These were carefully 

 removed and used to inoculate a great many kinds of culture media, the object being 

 to determine what forms of culture are adapted to the artificial growth of these 

 organisms. In all, about 70 kinds of culture media were used, and the formula for 

 preparation of the media and action of the organism in them are shown. The 1)est 

 results were obtained in nutrient media which contained urine, plant extracts, root 

 extracts, soil leachings, and soy bean seed extract. In these the organism made 

 good growth and produced the branching forms. In 10 days, in the soy bean plant 

 extract, there was a decided development of the organism which was short, compact, 

 and in some cases showing the characteristic branching which is one of the charac- 

 ters of the true bacteroids. 



Investigations concerning the occurrence of nitrogen-assimilating bacteria 

 in the soils, P. Necmann {Lamhr. TVr.s. Stat., 56 (1901), Xo. 2-3, pp. 20-3-206 ) .—In 

 tills arti le the author seems to give an account of the behavior of certain inoculation 

 materials in culture media rather than <liscuss the occurrence of nitrogen-a.ssimilating 

 bacteria in soils. Three forms of nutrient media were prepared — one from the above- 

 ground green plant of Viria faha, the second from the tubercles of the roots of the 

 jdant with its adhering earth, and the tiiird from i)eat. These me<lia were inoculated 

 with the washings from the roots and tubercles, with the jiressed juice from cho])ped 

 roots and tubercles, and with juice of the above-ground i>arts of the plant. Aft«r 14 

 days' standing in room temperature of from 15 to 20° C, the results are shown. lu 



