As Lars-Gunnar Romell has emphasized ('30, p. 842), "Burger ('22) with good reason, compares agricultural soil to an unorganized mass of building material, whereas the natural forest soil, with its definite, stable organization, is like a house built from this material." " It is more and more generally recognized that a natural soil, like a living organism, must be studied as a whole to get a correct idea of its responses " (Romell, '30, p. 843). Romell ('35b) has indicated that most chemical analyses of soils have included a study of the chemical actions initiated by the sampling method which kills the organisms in the sample. Similarly most physical analyses may be compared to treating a block of brick buildings with dynamite, war tanks and steam rollers, before studying it, and then making a report that the structure was composed of so many per cent of 2" X 4" X 8" red units and so many per cent gray dust. The nearly amorphous mass would give no indication of the former floor space, rooms, capacity, or use of the building. Yet natural soil is as highly organized as a huge apartment house and as well tenanted. All natural, shallow soil is a maze of tunnels and passageways averaging a millimeter in diameter, and harboring a varied and extensive population which keeps these channels open. The vertebrate animals (Taylor, '35), the larger insects (Blake, '26), the earthworms (Bornebush, '30, '32; Darwin, '81), the Protozoa (Cutler and Crump), and to a certain extent the Nematodes (Cobb, '14, '15) of the soil have been studied and their effect noted. The effect of Mollusca, which may not be important in the cold temperate zone, and the effect of the larger, Myriapoda, which is important in mesic woodland, have been largely neglected. But of greatest importance, the work of the microarthropods, comprising the Pauropods, Scolopendrellids, Proturans, Collembolans, and free living mites, has been entirely overlooked, probably due to their size, intermediate between the macroscopic and microscopic, and to the need of special methods to find or obtain them. As they are slow, "play possum" on being disturbed, and are earth-colored, they are not noticed in a handfull of earth, although present by the dozens, as may be ascertained in part by examination of such material on a blue card under the dissecting