SOIL PROTOZOA 329 



of the protozoa found in these far-away soils were identical with those 

 found in soils in temperate climates such as English soils. A detailed 

 study of numbers of protozoa in the soil is given elsewhere (p. 45). 



Classification and occurrence of protozoa in the soil. The majority of 

 soil protozoa are cosmopolitan, since the species found throughout the 

 world are, with some exceptions, identical, although not all the species 

 are found in every soil. Protozoa were demonstrated in large numbers in 

 the soil by Ehrenberg, 73 Greef, 74 and Rosenberg-Lip insky, 75 who considered 

 them to be of importance in soil fertility. In the more recent contribu- 

 tions to the subject, a study has been made of the occurrence of protozoa 

 in the soil and of the influence of environmental conditions upon their 

 distribution. 76-81 



Fellers and Allison 78 found 17 species of rhizopods, thirty-four flagel- 

 lates, and fifty-one ciliates in New Jersey soils, fertile soils containing 

 more species and greater numbers of protozoa than unfertile soils. They 

 concluded that the soil micro fauna consists principally of small, hardy 

 protozoa able to withstand, by means of encystation or otherwise, such 

 extremes of heat and cold, desiccation, aeration, etc., as are natural to 

 their life in the soil. Practically all species identified from the soil 

 have also been found in fresh water lakes, ponds, pools and streams of 

 New Jersey, but not in the same relative abundance, while several of 

 the most common plankton organisms are rarely found in the soil. 



Cutler and associates 79 found six species of protozoa occurring con- 



73 Ehrenberg, C. G. Die fossilen Infusorien und lebendige Dammerde. 

 1837. Berlin; Die Infusoriensthierchen als volkommene Organismen. 1839. 



74 Greef, R. t)ber einige in der Erde lebende Amoben und andere Rhizopoden. 

 Arch, micros. Anat., 2: 299-311. 1866. 



76 Rosenberg-Lipinsky, Alb. v. Der praktische Ackerbau (etc.), 2: 27. 1869, 

 Breslau. 



76 Wolff, Max. Der Einfluss der Bewasserung auf die Fauna der Ackerkrume 

 mit besonderer Berucksichtigung der Bodenprotozoen. Mitt. Kaiser Wilhelm 

 Inst. Landw. Bromberg., I: 382-401. 1909; Centrbl. Bakt. II, 33: 314-320. 

 1912. 



77 Martin and Lewin, 1914-1915 (p. 318). 



78 Fellers and Allison, 1920 (p. 326). 



79 Cutler, Crump and Sandon, 1922 (p. 32). 



80 Fantham, H. B., and Taylor, E. Some protozoa found in certain South 

 African soils. So. African Jour. Sci., 18: 373-393. 1922; 19: 340-371. 1922; 

 20: 437-492. 1923; 21: 445-479. 1924. 



81 Sandon, 1924 (p. 328); Sandon and Cutler, 1924 (p. 328); Sandon, H. The 

 composition and distribution of the protozoan fauna of the soil. Oliver and 

 Boyd. Edinburgh and London. 1927. 



