This was Darlington's first book, published by Macmillan in 1932. It was based on a series of articles published in the Gardeners' Chronicle in 1931. Hard-cover notebook, labelled 'G.C.' [Gardeners' Chronicle] on cover, and inside 'The Bearing of Chromosome Studies on Plant Breeding'. Pages numbered 1-69 and 70-81 with drafts, various contents lists, etc.