The first edition of Williams' Obstetrics appeared in 1903. The book immediately attained a commanding position among books on obstetrics and was widely used as a textbook and as a book of reference. It went through repeated editions, the sixth of which, after careful revision, was completed by Dr. Williams in 1930. During the years which had elapsed since the first edition appeared, the book had stood in the first rank of texts in the English language on the subject of obstetrics, if indeed it had not outranked all other books in that tongue.
The present revision was done by Dr. H. J. Stander, Dr. Williams' friend and former pupil. Dr. Stander has to a great extent maintained the form and arrangement of the book while adding needed new material and occasionally revising the old.
The first three chapters, devoted to anatomy and physiology, show no appreciable change. To chapter