Part 2 — Notes to Chapter XI.

For other detailed classifications of the causes of disease the reader is referred to the works of Sorauer and of Frank referred to in the last chapter. Also Kirchner, Pflanzen Krankheiten, Stuttgart, 1890.

Of more historical importance are the older classifications of Berkeley, Gardeners' Chronicle, 1854, and Re, Gardeners' Chronicle, 1849-50. These latter are interesting as showing the very different views held by the earlier workers, and comparison of these with the modern views helps to mark the progress of physiology during the half century which has intervened.