M. S. Ghilarov Summary
The soil as an environment is different for various dimensional groups of animals.
Microscopic organisms are active in soil water films and droplets. Microarthropods inhabit galleries, cracks and interstices between solid particles and their aggregates.
Only for larger animals (earthworms, millipedes, centipedes, insect larvae etc.) the soil represents a firm, even a solid medium.
Nomenclature applied to various dimensional animal groups is discussed. As various authors use term «microfauna» and «macrofauna» with respect to quite different groups of soil dwellers authors of the present mannal avoid them or use them Sensu Ghilarov, 1941, only.