multicellular diploid eukaryote in its earliest stage of development

An embryo is a multicellular diploid eukaryote in its earliest stage of development, from the time of fertilization through sexual reproduction until birth, hatching, or germination.


  • Hot tunnels alternated with cool tunnels. Coolness was wedded to discomfort in the form of hard X-rays. By the time they were decanted the embryos had a horror of cold. They were predestined to emigrate to the tropics, to be miner and acetate silk spinners and steel workers. Later on their minds would be made to endorse the judgment of their bodies. "We condition them to thrive on heat," concluded Mr. Foster. "Our colleagues upstairs will teach them to love it."
On Rack 10 rows of next generation's chemical workers were being trained in the toleration of lead, caustic soda, tar, chlorine. The first of a batch of two hundred and fifty embryonic rocket-plane engineers was just passing the eleven hundred metre mark on Rack 3. A special mechanism kept their containers in constant rotation. "To improve their sense of balance," Mr. Foster explained. "Doing repairs on the outside of a rocket in mid-air is a ticklish job. We slacken off the circulation when they're right way up, so that they're half starved, and double the flow of surrogate when they're upside down. They learn to associate topsy-turvydom with well-being; in fact, they're only truly happy when they're standing on their heads.
  • The Royal College of Obstetricians and Gynaecologists suggested that embryos should not be allowed to develop in vitro beyond a limit of seventeen days, as this is the point at which early neural development begins. The British Medical Association favoured a limit of fourteen days and a number of groups, including the Medical Research Council and the Royal College of Physicians suggested that the limit should be at the end of the implantation stage. Again, some groups submitting evidence suggested that no embryo which had gone beyond the beginning of the implantation stage should be used for research.
  • No live human embryo derived from in vitro fertilisation, whether frozen or unfrozen, may be kept alive, if not transferred to a woman beyond fourteen days after fertilisation, nor may it be used as a research subject beyond fourteen days after fertilisation. This fourteen day period does not include any time during which the embryo may have been frozen.
  • It has been suggested that if the demand for human gametes and embryos, for either treatment or for research, increased, there could be a risk of commercial exploitation and of an export and import trade. We would see this as undesirable. On the other hand we can foresee situations where the supply of human gametes or embryos might reasonably involve some commercial transaction, for example if a licensed semen bank was asked to supply specimens to a distant part of the country which would involve them in considerable costs of transportation, we see no reason why they should not seek reimbursement of expenses. Thus a complete prohibition on the purchase or sale of such material would be inappropriate.