This year's volume of the Annual Review of Physiology contains some chapters which continue subjects from last year's volume, namely reproduction; kidneys, water, and electrolytes; respiration; heart; peripheral circulation; alimentary tract; nerve excitation and synaptic transmission; visceral, somatic, and higher functions of the nervous system; and the adenohypophysis and adrenal cortex. Topics not represented in last year's volume are nuclear function and nuclear-cytoplasmic interactions, physiological aspects of genetics, developmental physiology, fuel of muscle metabolism, blood pigments, blood volume regulation, and physiology of vision. Last year's chapter on the pancreas, insulin, and glucagon is followed this year by a chapter on the thyroid.
The amount of research work reviewed in these annual volumes is staggering, and the authors of the reviews deserve recognition for undertaking the labor of organizing the mass of new information and making it accessible to their colleagues. Fortunately the modern machinery for handling bibliographic data has facilitated