As a result, a secondary complex of axial organs including head structures was formed at the place of a transplant. Recent studies into the history of this discovery ( Sander, 1993) have detected that the decisive experiment had been made by Hilda Mangold in 1921 when she transplanted a piece of dorsal lip of the ring-like blastopore of a Triturus embryo to the ventral side of another embryo at the same stage. They had observed that after transplantation of a dorsal blastopore lip of the early gastrula to the ventral side of another embryo a secondary embryonic axis developed on this side. Mangold discovered the so-called “organizer” in amphibian embryos ( Spemann and Mangold, 1924). Sometimes it seems that to the end of XX century the embryologists are further from the original goal to explain how the development of an organism is accomplished than it seemed at the beginning of the century when H. Up to now researches are far from understanding fully the mechanisms which realize the embryonic development of vertebrate animals. The researches of many commentators have already thrown much darkness on the subject, and it is probable that, if they continue, we shall soon know nothing at all about it.
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