Much work has been done on the distribution of species at different depths in the soil, but the results are still confusing. Thus, examining eighteen species, Goddard[7] found no difference in relative distribution down to 5½ inches. Werkenthin[26] found identical species from 1-4 inches, and then an absence of fungi from 5-7 inches, which latter was the greatest depth he examined. Waksman[25] found little difference in the first six inches, but very few species below 8 inches except _Zygorrhynchus vuilleminii_, which extended down to 30 inches and was often the only species occurring below 12 inches. Taylor[23] has reported species of _Fusarium_ at practically every depth to 24 inches. Rathbun[19] found _Aspergillus niger_, _Rhizopus nigricans_, and species of Fusarium and Mucor down to 34 inches, and _Oospora lactis_, _Trichoderma koningi_, _Zygorrhynchus vuilleminii_ and species of _Penicillium_, _Spicaria_ and _Saccharomyces_ as deep as 44 inches. Eleven species were isolated from the alimentary canal of grubs and worms, and Rathbun concluded that soil fungi may be spread by these organisms. On an unmanured grass plot at Rothamsted twenty species were isolated from a depth of 1 inch, nineteen from 6 inches, and eleven from 12 inches, whereas on the unmanured plot of Broadbalk wheat field twenty-six species were obtained from 1 inch, seven from 6 inches, and five from 12 inches. There appeared to be no conspicuous differences between the floras of the two plots save that in the Broadbalk plot there were fewer Mucorales, and _Zygorrhynchus mœlleri_ and _Absidia cylindrospora_ were absent. In the grass plot samples about one-half the forms occurring at the lower levels were isolated also from the upper levels, but in the Broadbalk sample the five forms isolated from 12 inches, and five out of seven of those at 6 inches occurred only at those levels, i.e. each of the three levels appeared to have a specific flora. The difference in depth distribution in these two cases may be due to the fact that in the Broadbalk plot the stiff clay subsoil occurs at 5-7 inches, whereas in the grass plot the depth of soil is greater than 12 inches. Much further work needs to be done on this aspect before any definite conclusion can be reached.