This is an interesting book on the history of physiology, even if the greater emphasis (in content) is on the rise in our knowledge of the physiology of circulation, respiration and digestion to the virtual exclusion of other fields, such as the nervous system, metabolism, endocrine glands and special senses. In this respect it lacks balance, which is unfortunate since it is written in a fascinating style. Aside from this lack of balance there are several errors which no doubt will be corrected in subsequent editions. It was Baumann in 1895, and not Gley, who discovered iodine in the thyroid gland. Tashiro first measured the carbon dioxide production of nerve in the University of Chicago laboratory of A. P. (not E. B.) Mathews. Carl Ludwig wrote virtually all the publications of his 200 pupils, whereas Fulton perpetuates the common error that Ludwig did "little independent writing."