Egg transfer was first performed in 1890, but for half a century it received scant attention. However, since 1950 the technique has become increasingly widely used - in the laboratory for fundamental studies and more recently in practice, both veterinary and medical, to boost reproductive potential of genetically superior cattle and to overcome sterility due to impaired rubal function in women. As a result, a considerable body of literature has accumulated, totaling well in excess of a thousand references. But till now there has not been a single comprehensive text devoted solely to this subject. The present work was designed to meet that need at a time when the field is fast expanding with new techniques and approaches constantly being evolved. One need only cite the tremendous rate of progress in human egg transfer in the last three years. The work embraces laboratory and farm animals and primates, including man, altogether representing a total of 16 species.