III. On the tubercular swellings on the roots of vicia faba

In this paper the author gives a detailed account of his investigations, of which a preliminary note appeared at p. 331. The following are the main conclusions :— The tubercles always contain a fungus, allied to the Ustilaginese, which enters the root by way of the root hairs. The ultimate branches of the hyphge in the cells of the tubercle bud off minute bodies (gemmules), which are afterwards scattered in the soil. This process resembles the budding discovered in Ustilagineas by Brefeld. By means of cultures and observations the author shows that the infection from the soil is probably due to these minute gemmules acting as spores.