This excellent treatise, the first edition of which appeared only a year ago, has been revised with the addition of a ninety page appendix to include the new literature up to Jan. 1, 1937. Minor changes have also been made in the original text. As pointed out in the review of the first edition (The Journal, Aug. 26, 1936) the author has handled a difficult subject with remarkable facility; the result is a concise and lucid dissertation on the naturally occurring sterols and related substances. Those who desire to keep abreast of the rapid and extremely important developments in the chemistry of the estrogens, androgens, cardiac glucosides, bile acids, carcinogenic substances and the like will find this book indispensable. It contains in readily available form material not elsewhere accessible in one volume.