Editing Embryology (section)

===Embryology in Jewish tradition===

Many Jewish authors also discussed notions of embryology, especially as they appear in the [[Talmud]]. Much of the embryological data in the Talmud is part of discussions related to the impurity of the mother after childbirth. The embryo was described as the ''peri habbetten'' (fruit of the body) and it developed through various stages: (1) ''golem'' (formless and rolled-up) (2) ''shefir meruqqam'' (embroidered foetus) (3) ''ubbar'' (something carried) (4) ''walad'' (child) (5) ''walad shel qayama'' (viable child) (6) ''ben she-kallu khadashaw'' (child whose months have been completed). 

Some mystical notions regarding embryology appear in the [[Sefer Yetzirah]]. The text in the [[Book of Job]] relating to the fetus forming by analogy to the curdling of milk into cheese was cited in the Babylonian Talmud and in even greater detail in the [[Midrash]]: "When the womb of the woman is full of retained blood which then comes forth to the area of her menstruation, by the will of the Lord comes a drop of white-matter which falls into it: at once the embryo is created. [This can be] compared to milk being put in a vessel: if you add to it some lab-ferment [drug or herb], it coagulates and stands still; if not, the milk remains liquid."<ref name="kot" /> The Talmud sages held that there were two seeds that participated in the formation of the embryo, one from the male and one from the female, and that their relative proportions determine whether that develops into a male or a female. 

In the Tractate Nidda, the mother was said to provide a "red-seed" which allows for the development of skin, flesh, hair, and the black part of the eye (pupil), whereas the father provides the "white-seed" which forms the bones, nerves, brain, and the white part of the eye. And finally, God himself was thought to provide the spirit and soul, facial expressions, capacity for hearing and vision, movement, comprehension, and intelligence. Not all strands of Jewish tradition accepted that both the male and female contributed parts to the formation of the fetus. 

The 13th century medieval commentator [[Nachmanides]], for example, rejected the female contribution. In Tractate Hullin in the Talmud, whether the organs of the child resemble more closely those of the mother or father is said to depend on which one contribute more matter to the embryo depending on the child. Rabbi Ishmael and other sages are said to have disagreed on one matter: they agreed that the male embryo developed on the 41st day, but disagreed on whether this was the case for the female embryo. Some believed that the female embryo was complete later, whereas others held that they were finished at the same time. The only ancient Jewish authors who associated abortion with homicide were [[Josephus]] and [[Philo of Alexandria]] in the 1st century. In the Talmud, a child is granted humanness at birth, while other rabbinical texts place it at the 13th postnatal day.<ref>{{Cite journal |last=Schenker |first=Joseph G. |date=June 2008 |title=The beginning of human life |url=http://dx.doi.org/10.1007/s10815-008-9221-6 |journal=Journal of Assisted Reproduction and Genetics |volume=25 |issue=6 |pages=271–276 |doi=10.1007/s10815-008-9221-6 |pmid=18551364 |pmc=2582082 |issn=1058-0468}}</ref>   

Some Talmudic texts discuss magical influences on the development of the embryo, such as one text which claims that if one sleeps on a bed that is pointed to the north–south will have a male child. According to Nachmanides, a child born of a cold drop of semen will be foolish, one born from a warm drop of semen will be passionate and irascible, and one born from a semen drop of medium temperature will be clever and level-headed. Some Talmudic discussions follow from [[Hippocrates|Hippocratic]] claims that a child born on the eighth month could not survive, whereas others follow Aristotle in claiming that they sometimes could survive. One text even says that survival is possible on the seventh month, but not the eighth. Talmudic embryology, in various aspects, follows Greek discourses especially from Hippocrates and Aristotle, but in other areas, makes novel statements on the subject.<ref name="kot" />

Judaism allows assisted reproduction, such as IVF embryo transfer and maternal surrogacy, when the spermatozoon and oocyte originate from the respective husband and wife.<ref>{{Cite journal |last=Schenker |first=Joseph G. |date=2013-09-03 |title=Human reproduction: Jewish perspectives |url=http://dx.doi.org/10.3109/09513590.2013.825715 |journal=Gynecological Endocrinology |volume=29 |issue=11 |pages=945–948 |doi=10.3109/09513590.2013.825715 |pmid=24000935 |issn=0951-3590}}</ref>