This most recent volume of an annual series lives up to the reputation established by its predecessors as a valuable summary of the previous year's contribution to physiology. The prefatory chapter this year, by Dr. Carl J. Wiggers, recounts his views on "Physiology from 1900 to 1920: Incidents, Accidents, and Advances." The seventeen reviews, each by an authority in the field, include the following subjects: permeability; biological effects of radiations; developmental physiology; physiological effects of heat and cold; muscle; digestive system; liver; peripheral circulation; heart; respiration; kidney; conduction and transmission of nerve impulses; somatic functions of the nervous system; electrical activity of the brain; metabolic functions of the endocrine glands; physiology of reproduction, and blood volume.
The 450-page volume is carefully indexed with respect both to subjects and to authors of articles reviewed. This annual series, together with its companion series in biochemistry, microbiology, psychology, and medicine, reveals in striking