The author of this treatise has endeavored to include in one book all the essential methods of investigation on the glands of internal secretion. There are detailed reference in this first volume to the thyroid, parathyroid, adrenal cortex, adrenal medulla and pancreas. The result is encyclopedic. A vast amount of information not elsewhere accessible in convenient form is gathered here. This includes details of anatomy, surgical technic (including forms and dosages of anesthetics for various laboratory animals), methods of handling and administering extracts to animals, blood histology and blood chemistry of different species, histologic technic, methods of recording physiologic changes, methods of extraction and purification of glandular extracts, methods of controlling hydrogen ion concentration including tables of indicators, detailed consideration of the physiology of each of the five glands mentioned with reviews of the literature, tables of patents on glandular products and a thousand other items too numerous to mention.