Medical Electrical Equipment

and could be read with profit by anyone interested in the problem of hydramnios. The Morphologic Manifestations of Uptake of Materials by the Yolk Sac of the Pregnant Rabbit describes how colloidal gold, erythrocytes, cream, and protein, in the form of egg white, are absorbed by the yolk sac. There are several electron microphotographs which are used to illustrate some of the processes. The Development of Fetal Immunity points out the difference between the human and several of the experimental animals. Dr. Brambell's work has been largely concerned with the rat. He shows that in this animal, fetal immunity is partially acquired before birth through the gastro-intestinal tract somewhat, but more importantly by the yolk sac, and after birth, for the first 21 days, through the gastro-intestinal tract. The Proceedings of the Fourth Conference on Gestation are extremely enlightening to those interested in the specific fields covered. This type of conference cannot be too highly praised.