Dr. George Washington Corner, one of the most eminent embryologists in the United States, has written in this book an account of what happens to man (and other mammals) before birth. Here is the latest knowledge in the possession of the embryologist, presented so that the layman can read it; the story of the miraculous change from a single cell to an organism two billion times its original size, ready to take its place in the open air of the outside world. Here is also the story of what is and what is not true in beliefs about prenatal shocks to the mother and their effects on the offspring, ranging from the myths of sights and foods to avoid to the all-too-true accounts of what a comparatively harmless virus can do to the embryo. This book in its complete outline of the vicissitudes of the prenatal cells is an important document for any member of the human race.