NON-PROTOZOAN FAUNA OF SOIL 363 



nitrogen for the algae; all three forms serve as food for rhizopods and 

 together with these they serve as food for rotatoria and nematodes ; the 

 latter are eaten by amoebae, myriapodes, insects, etc.; these are, in 

 turn, decomposed by the fungi and bacteria. 



It is sufficient to call attention to the role of termites (Hodotermes) 

 in certain soils, to obtain an idea as to the probable importance of the 

 animal population in soil processes. Termites live in tropical and 

 subtropical countries, not only in wooden structures, in which they 

 cause active decomposition of organic matter of living and dead plants, 

 but also in the soil itself. The underground termites are found in 

 great abundance in dry countries and in deserts. They form a great 

 abundance of nests, which are connected by a net of underground pas- 

 sages. These termite nests make the soil very porous, with the result 

 that there is a great increase in the amount of water required for satura- 

 tion of the soil. The activities of the termites in the soil result in 

 increases in the concentration of salts. These increases may be from 

 0.06 to 1.3 per cent. The termites, as a result of the numerous pas- 

 sages formed in the soil, appreciably improve soil drainage. 65 



65 Dimo, N. A. The role and importance of termites in the life of soils and sub- 

 soils of Turkestan (Russian). In Soil and Bot. Geogr. Investig. of the basins of 

 Amu-Daria and Sir-Daria. Moskau, 2: 1-38. 1916. 



