(b) "The ancients had wondered about reproduction, of course. Aristotle opened up fertilized chicken eggs at intervals to observe the development of the embryos and mused that human embryos underwent the same kind of transformation. He believed that a human baby was initially formed from the man's semen being 'curdled' by the women's menstrual blood, 'the same way,' he asserted, 'as rennet acts upon milk' to form cheese.
(c) "In the early 1500s men began [dissecting dead bodies] * * * 'At the same time he was painting the Mona Lisa,' we learn [from this book], 'Leonard was cutting open the faces of corpses and dissecting the muscles of the mouth and lips, to sort out the secrets of the smile.' This was the opening salvo of the Scientific Revolution. * * * By the middle of the 1600s the English Physician William Harvey, who discovered that the heart is a pump circulating blood around the body, was arguing all mammals, including humans, came from eggs inside the mother. 'Ex ovo omnia,' became his motto: 'Everything comes from the egg.' But what he had seen during the dissections were not eggs, only small clusters of cells making up early-stage embryos in the uterus.
(d) "In 1672, Regnier de Graaf, a Dutch physician, sliced open rabbits at increasing intervals after copulation. He used a microscope to watch eggs burst out of the ovary; soon afterward, tiny embryos appeared in the uterus. * * * What he observed
(i) That account is untrue, about "egg" and "microscope" -- he did not see eggs, because he did not have, but was aware of development of, a microscope.
"A few months before his death [in 1673] De Graaf recommended, as a correspondent of the Royal Society in London, that attention be paid to Antonie van Leeuwenhoek [both lived in the same city: Delft] and his work on the improvement of the microscope."
https://en.wikipedia.org/wiki/Regnier_de_Graaf
(ii) The following account is historically correct.
Ellen M Dupont, Regnier de Graaf (1641-1673). In The Embryo Project Encyclopaedia. Arizona State University, Sept 30, 2008
https://embryo.asu.edu/pages/regnier-de-graaf-1641-1673
("de Graaf's research was plagued by several misconceptions stemming mostly from the lack of microscopic equipment at the time. Interestingly, all de Graaf's work took place more than 150 years before Karl Ernst von Baer first identified the ovum [another scientific term is 'oocyte'] in 1827. * * * De Graaf deduced its existence from his knowledge of ectopic (tubal) pregnancies, and he was aware of the unidentified object's [the unidentified object is a fertilized egg, or zygote] path of travel. However, he mistakenly believed that the egg actually consisted of the [mature] ovarian follicle [which is quite big to be observed with naked eye] itself, which he thought detached from the ovary and entered the Fallopian tube. Though de Graaf's theory was incorrect, he did realize that the structure traveling down the Fallopian tube [also known as oviduct] was significantly smaller than the supposed parent follicle, an inconsistency he was never able to explain. With the help of highly improved microscopic equipment, future scientists would reveal that the Graafian follicles actually rupture, releasing the mature egg into the tube. * * * Among de Graaf’s notable accomplishments was his comparison of pre- and post-mating ovaries; the structural differences he noted led to his realization of the morphological changes that accompany the ovary's functioning"
(iii)
(A) The Dutch surname de Graaf: "from graaf count (see [German surname] Graf), with the addition of the definite article de"
(B) Dutch-English dictionary:
* graaf (noun masculine): "earl, count"
https://en.wiktionary.org/wiki/graaf
(iv) Karl Ernst von Baer
https://en.wikipedia.org/wiki/Karl_Ernst_von_Baer
(was born into a Baltic German noble family of Russian Empire, in present-day Estonia)
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发表于 6-12-2017 15:18:06
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