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невыведенная бластоциста? http://www.lifeissues.net/writers/irvi/irvi_30delawarecloningban2.html The only entity to which the terms "hatched" and "unhatched" refers in human embryology is the very earliest human embryo, from Stage One through Stage Three (the "free blastocyst" and part of Stage Four (the "implanting blastocyst") - before, or during, implantation. Each of these earliest of human embryos - whether reproduced sexually or asexually -- are surrounded by a protective membrane called the "zona pellucida". This membrane slowly dissolves as the already existing embryo moves through the fallopian tubes and then tries to implant in the uterus (about 5-7 days after zygote formation). In in vitro fertilization (IVF, sexual reproduction), the zona is sometimes mechanically dissolved by the technician while still in the petri dish - otherwise it will not be able to implant when inserted into the uterus. In such circles the embryo is thus said to have "hatched" - i.e., the zona surrounding the early embryo has dissolved. (The fallopian tubes are usually by-passed). If the zona does not dissolve, the embryo cannot implant, and it will die. The same would be true for an embryo reproduced by cloning before it was implanted. Certainly by the end of Stage Four, there is no zona remaining in normal human embryogenesis; the embryo has "hatched" and is implanting - and the zona does not grow back again at some later stage of development - especially many weeks later during the fetal period!
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