This "Transactions of the Third Conference on Connective Tissue" is presented in essentially the same manner as all the Macy Conferences. Although the reader cannot profit as much from the Transactions as those who were present at the conference profited from the discussion themselves, this book should interest all who work with corticotropin and cortisone in the laboratory or who treat patients with these drugs. Furthermore, the Transactions contains interesting material on the fine structure of connective tissue, including excellent electromicrograms illustrating the architecture of connective tissue. Connective tissue staining, the nature of reticulin, and hypersensitivity and the hyperadrenal state are also discussed. The questions asked and the replies, as usual, should interest the reader from many points of view. This book is highly recommended to all persons in medicine, including medical students.