The new edition of this well known text is in the main a reprinting with such additions and alterations as could be incorporated without enlarging the work. Among the more important changes or additions are the treatment of the structures of the disaccharides and polysaccharides and nucleic acid, the recent advances in nerve and muscle metabolism and the biochemistry of hemoglobin, bilirubin, sterols, bile acids, allantoin, hormones and vitamins. The work retains all of the outstanding features so characteristic of the author's writings. His style, originality and versatility are as refreshing and as entertaining as ever. He continues to accomplish what he hoped to attain in his first edition, namely, "to raise in the minds of those who read it more questions than it answers."