It is in 3 parts, with generous illustrations throughout. The first part gives a brief account of the author’s discovery of a foetal heart in 1965, which is followed by descriptions of his dissections of foetal lambs and the valuable information they give. The second part covers the author’s comprehensive account of the human foetal circulation, which he divides into three sections: for the upper body, lower body and placenta. The structure and function of the lung are compared with those of the placenta. Details of the foramen ovale are given, and the importance of the 3rd heart sound made by the valve. In part 3 the author gives his own ideas of the birth changes. He insists that it is the foetus which is delivered, and that the baby is born after delivery when the first deep breath is taken, which changes the hidden foetal features into those of the baby. He has suggestions for the management of delay in the onset of breathing. He shows why there has been discord between the orthodox accounts and his own. He suggests research in the chick embryo, which has a circulation similar to that of the human foetus.