This book comprises a series of papers in which biologists, obstetricians, pathologists, and pediatricians express their views on the etiology and preventive treatment of fetal wastage. Much of the fundamental research on early pregnancy in man and the lower animals is presented. The endometrium is studied at the time of nidation, and various blighted ova are depicted in the earliest stages of development. Controlled experiments on gamete age at the time of fertilization in cattle are described. The metabolism of placental tissue, corticotropin, and pregnancy is evaluated, and there is evidence that pregnancy is associated with an increase in this hormone and that the placenta is the probable source. This, of course, could hardly be otherwise when we consider the relationship of this organ to other endocrine glands.
Young shows that in lower animals the age of the gamete is important for normal fertilization, nidation, and development. He bases this