This 1959 book takes as its starting point Sir George Watt's Wild and Cultivated Cotton Plants of the World published in 1907, and discusses the findings of the subsequent fifty years, updating, in the light of extensive subsequent work, the account given by Hutchinson, Silow and Stephens in The Evolution of Gossypium (1947). Sir Joseph reviews the range of the genus Gosgpium and the place in it of the four species which constitute the cotton of commerce. He traces the historical development of these species from the coarse, short, perennials grown over 4000 years ago to their more modern annuals. He describes the development of disease-resistant strains, by hybridisation of races from different parts of the world. The book constitutes a valuable account of the results which can be achieved in a relatively short time by the application of genetic and physiological studies to the problems of a commercial crop.