This book may be regarded as the culmination of the life's work of an unusually gifted woman who devoted the last twenty years of her life unstintingly, and almost exclusively, to the study of cancer in women. Sadly, Dr. Hurdon did not live to see the publication of her work. A few months before her death in January 1941, she placed the manuscript, with a view to its publication, in the hands of Dr. Louisa Martindale and Professor Russ, to whom a considerable debt of gratitude is due for seeing it through the press.