SOILS — FERTILIZERS. 621 



The results show that Streptothrix composed from 20 to 30 per cent of the 

 micro-organisms in loam soils, from 8 to 15 per cent in clay soils, and from 7 

 to 10 per cent in sands. Fallow soils contained larger numbers than cultivated 

 soils. The organisms were also abundant on roots of Aspidium, Quercus, 

 Ulmus, Gramiueae, and Papilionacese, and on decaying plant debris. 



Streptothrix decomposed peptone, blood, bone meal, and straw, splitting off 

 large quantities of ammonia. For culture puiposes media containing milk sugar 

 and grape sugar were especially well adapted. Cellulose may also be used as a 

 source of carbon. The optimum temperature for the development of the organ- 

 isms was 20° C, although there was a good, but very slow, development at 

 lower temperatures. 



Streptothrix produced no nitrification. On the other hand, there was strong 

 reduction of nitrates to nitrite, but without direct denitriflcation, i. e., without 

 loss of free nitrogen. 



In view of the ready assimilation of nitrates, ammonium compounds, urea, 

 and uric acid, it would appear that these organisms are instrumental to a 

 prominent degree in fixing the niti'ogeu of fertilizers and soils and thereby 

 diminishing the loss from denitrification. There was no assimilation of free 

 nitrogen by Streptothrix, but the presence of these organisms did not diminish 

 the assimilative capacity of Azotobacter for free nitrogen. 



Streptothrix had a favorable effect on the growth of certain plants. This 

 may be regarded as being due to the rapid decomposition of the organic matter 

 whereby plant nutrients, especially assimilable nitrogenous compounds, are set 

 free. It would also seem that these organisms aid in the production of nodules 

 on Papilionacese. 



The agricere and the bacteriotoxins of the soil, R. Geeig-Smith (Proc. Linn. 

 8oc. N. S. Wales, 36 {1911), pt. J,, pp. 679-699; CentN. Bakt. [etc.], 2. AM., 34 

 (1912), No. 8-9, pp. 22Jf-226). — The author reports experiments which led him 

 to believe that the chief reason for the increased bacterial activity in soils 

 following antiseptic treatment with such fat solvents as chloroform, ether, etc., 

 is the removal of the fatty protective covering of the soil particles (agricere) 

 referred to in a previous article (E. S. R., 25, p. 525). 



Beneficial effect of creatinin and creatin on growth, J. J. Skinner (Bot. 

 Gaz., 54 (1912), No. 2, pp. 152-163, fig. i).— In water cultures with wheat seed- 

 lings creatinin and creatin increased growth both in presence and in absence 

 of nitrate. These substances were apparently able to replace nitrates in plant 

 growth. They also increased the assimilation of phosphoric acid and potash. 



Partial sterilization of soil, R. B. McBride (Pharm. Jour. [London], 4- ser., 

 34 (1912), No. 2527, p. 381; abs. in Cliem. Ahs., 6 (1912), No. 15, pp. 2127, 

 2128). — It is reported that the growth of sweet peas was increased by sprink- 

 ling the soil with a solution of potassium permanganate, 2 oz. to 25 gal. of water. 

 The solution was also effective in destroying the green fly on rose bushes. 



Partial sterilization of soil for greenhouses, E. J." Russell and F. R. 

 Pethekbeidge (Phann. Jour. [London], 4. ser., 34 (1912), No. 2524, PP- 286, 

 287). — This is an abstract of an article already noted from another source 

 (E. S. R., 26, p. 815). 



Clearing heavy lands as adapted to Montaja and Panendjoan, E. Van 

 Lennep (Teysmannia, 23 (1912), No. 4, pp. 211-229, pis. 4). — The author de- 

 scribes a so-called ditching system of clearing, cultivating, and aerating land 

 overgrown with dense second growth of shrubbery and grasses and isolated 

 trees. The method is stated to be extensively and successfully used in the prep- 

 aration of land for the cinchona plant in different sections of Java. 



Reclamation of crawfish lands, W. D. Garrison (South Carolina Sta. Bui. 

 167, pp. 12, pis. 10). — The term crawfish lauds is taken to represent the lower 



