In recent years the fauna of the soil has been receiving more attention and interest has centred especially on earthworms and the functions they subserve. A number of experiments have been devised in order to learn more of their influence on the relations between plant and soil, and among the accounts of recent work that of Hopp and Slater (1) is one of the more important. These two workers in a series ' of five pot experiments showed that with different crops and soils of varying fertility the earthworms consistently increased the plant yields. The increases varied between 43 per cent. for millet in one soil and 350 per cent. for wheat in another. The addition of dead earthworms also significantly increased the yields, but to a less degree than was the case with living ones.
