48 



PRINCIPLES OF SOIL MICROBIOLOGY 



fertile soil has a protozoan content approximating 10,000 per gram, the 

 flagellates constituting the greater portion; about 100 ciliates were 

 found per gram; certain types of protozoa are active in the soil under 



TABLE 9 

 Influence of organic matter on numbers of protozoa in the soil {average of 10 counts) 117 



* C = ciliates, F = flagellates, A = amoebae. 



TABLE 10 

 Influence of soil depth upon the numbers of protozoa 111 



TABLE 11 

 Numbers of protozoa and bacteria per gram of soil from two Broadbalk plots 119 



normal and even sub-normal conditions of moisture, the active forms 

 being probably restricted to the flagellates. Although the amoebae are 

 also widely distributed in the soil, 115 their numbers have not been re- 



116 Martin, C. H., and Lewin, K. R. Some notes on soil protozoa. Phil. 

 Trans. Roy. Soc. London, 205B: 77-94. 1914; Jour. Agr. Sci. 7: 106-119. 1915. 



