Contributions to the History of the Germinal Vesicle, and of the First Embryonic Nucleus

I have had the honour of presenting to the Academy a summary exposition of the results of my researches on the maturation of the ovule, the fecundation and earliest phenomena in the embryonic development of the rabbit, up to the moment of the appearance of the primitive streak more especially. I have made known those of my researches which establish the disappearance of the germinal vesicle, the formation of the directive bodies (Richtungsbläschen of Fritz Müller), and the appearance of the first embryonic nucleus. The recent publication of the researches of Auerbach,¹ Bütschli,² and Strasburger,³ on the formation and division of the nuclei of cells, led me, in the course of my researches on the development of mammalia, to investigate very specially how the first nucleus of the embryo appears and how cells multiply in the embryonic laminæ. Long before I became acquainted with these researches, I had observed that the germinal vesicle of the rabbit disappears, independent of fecundation, and that the disappearance of this element is the indication of the complete maturity of the ovum.