514 EXPEEIMENT STATTOISr EECOED. 



Cyanophyceae were found in 40 out of 45 samples of subsoils of cultivated 

 sand, loam, and marsh soils. In all these cases Cyanophyceae had been found 

 in the surface soil and the species in surface and subsoil corresponded per- 

 fectly. This is attributed largely to cultivation. The algne were also found in 

 23 out of 32 subsoil samples of the same soils when uncultivated, although in 

 several of these cases no algae were found in the surface soil. It is concluded, 

 however, that the occurrence of Cyanophycere in subsoils of uncultivated soils 

 is due largely to displacement from the surface soil by natural agencies. Cyano- 

 phyceae were found to be widely distributed in the deeper layers of moist sand 

 soils from three different localities, while the subsoils of forest, heather, and 

 moor soils contained practically none. 



Further experiments with sterilized and unsterilized subsoils inoculated with 

 artificial cultures of Cyanophyceae led to the belief that at least certain kinds 

 of Cyanophyceae can exist for a long time in the soil, depending largely on its 

 content of nutritive constituents, but that Cyanophyceae can only indirectly 

 take a part in niti-ogen fixation. The importance of further investigation along 

 this line is discussed. 



A classified list of the species of Cyanophyceae found is included. 



The effect of climate on soil formation, J. W. Leather {Jour. Afir. Sci. 

 [Etiffland], 7 {1915), No. 2, pp. 135, 136). — "With reference to a previous article 

 by Russell (E. S. R., 31, p. 214) it is stated that the formation of the mineral 

 framework of the lateritic and " black cotton " soils of India can not be at- 

 tributed simply to either weather or climate. 



Observations on heating of the surface soil in 1914, MtJNCH {Natnrto. 

 Ztschr. Forst u. Lnndw., 13 {1915), Xo. 6-7. pp. 2-'/ 9-260) .—The results of obser- 

 vations made in April, May, June, and July on the temperature of loose sandy 

 and sandy humus soils are reported, together with the corresponding metero- 

 logical data, the purpose being to determine the influence of meteorological 

 conditions, the color and density of the soil, and the soil covering on soil tem- 

 perature. 



It was found that the higher soil temperatures very frequently occurred on 

 rather cool days. The soil temperature was also higher the drier, looser, and 

 darker the soil. The damp soil never reached a temperature injurious to vege- 

 tation. The deeper layers of loose soil subjected to direct sunlight were, how- 

 ever, cooler than the deeper layers of dense soil. Rolling and packing of loose 

 soils with lower temperatures in the deeper layers and excessive surface evap- 

 oration was profitable. Next to that of raw humus, the highest temperature 

 was observed in soil covered with pine needles. Heat radiation from the soil 

 was found to be governed largely by the nature of the soil covering and the 

 existence of side protections, such as trees and bushes. 



Soil gases, J. W. Leather {Jour. Agr. Sci. [Englaiid], 7 {1915). No. 2. pp. 

 240, 241). — The author interprets the results of previous experiments by Rus- 

 sell and Appleyard (E. S. R., 33, p. 618) and of similar experiments l)y himself 

 on Pusa soil as indicating that the gases, extracted from soils which had been 

 botttled, the air extracted, and the soil allowed to stand for one or more days, 

 were of comparatively large volume and were " formed and liberated gradually, 

 presumably by bacterial action." 



Soil gases, A. Appleyard and E. J. Russell {Jour. Agr. Sci. [E7igla7i^], 7 

 {1915), No. 2, p. 2Jf2).— This is a reply to the above. 



Soil ventilation, A. and G. L. C. Howard {Agr. Research Inst. Pusa [India] 

 Bui. 52 {1915). pp. 35, fig. 1; abs. in Infernat. In^t. Agr. [Rome], Mo. Bui. Agr. 

 Intel, and Plant Diseases, 6 {1915), No. 7, pp. 918, 919). — This paper reports 

 experiments on aeration of the alluvial .soils of the Indo-Oangetic plain and 

 the results of long continued observations on the influence of soil ventilation on 



