In this paper I have not, of course, presented all the embryological data that can be collected from the Talmudic and Midrashic literature. More details can be found in Julius Preuss' classical work on biblical and talmudic medicine, now available in Fred Rosner's English translation and in a French M.D. thesis by Martine Michel.75 I also did not present any data on teratology, and did not deal with the very rich Jewish mystical lore, the Cabbala. But a few comments are (...) in order here about the material on embryology.There are very few original ideas in the Talmudic corpus on embryology, but it is obvious that the Sages were well aware of the Greek and Roman theories on embryology.The fact that the Talmud is a compilation that was built up slowly, during several centuries, explains why the information recorded in it cannot be ascribed solely to one school of thought or one clear-cut influence.When a definite problem was difficult to solve because there were many different theories about it, the Sages based their opinion on a famous experiment that seemed to offer guarantees of validity. This was the case with the controversial problem of the formation of the embryo and its sexual differentiation, where the Sages made use of an experiment allegedly initiated by Cleopatra.The Sages were ready to discuss scientific problems with non-Jewish scholars and even to accept their arguments. This was the case with the important topic of the time of the entry of the soul into the embryo. But the legal conclusions drawn from the Sages' opinion were not consistent with those declared by Churth Fathers such as Tertullian. Embryotomy, for instance, was permitted by Jewish law.Wide interest, scholarly discussions, suggestive descriptions and readiness to inquire and to obtain detailed information characterized the Talmudic discussions of embryology.In conclusion, I quote a Talmudic text that reviews the whole process of embryological development through the sequence of prayers of a faithful Jew who learns that his wife is expecting a baby.The first three days, [he should pray to the Lord] that the seed should not putrefy.From the third to the fortieth day: that the child should be a male.From the fortieth day to the third month: that there should not occur any superfetation, which could lead the first embryo to be a fetus compressus.From the third to the sixth month: that an abortion should not occur.From the sixth to the ninth month: that the birth should be without problems.76. (shrink)