The seventh edition of this standard work in physiology appears after a lapse of five years. As this is a rather long interval from the time of the previous publication, there has necessarily been considerable revision of the text. One of the changes has been the removal of the word biochemistry from the title. Other new departures include the complete rewriting of certain chapters, a bibliography at the end of the volume instead of references at the end of each section and the addition of several new contributors. Most of the sections have been written by Macleod. The rather long Part III has been extensively revised by E. P. Carter. The section on the endocrine organs has been revised by N. B. Taylor, and the section on the neuromuscular system, also quite long, has been rewritten by Philip Bard, whose name has not previously appeared in the list of co-authors.