regarding the prohibition against using as ordinary food the flesh of animals killed for sacred purposes. Animals injured by disease, accident, or animal attack. The Mishnah enumerates eighteen diseases and injuries which render an animal terefah, including perforations of the lungs or of the small intestines, and fractures of the spine or of the ribs. It also cites diseases and injuries that do not render the animal terefah, and concludes by listing the signs of kosher animals. Embryos, living or dead, found in a slaughtered female animal; on the Caesarian section. The prohibition against slaughtering an animal and its offspring on the same day. If both animals have been consecrated and killed within the Temple precincts, the animal first killed may be used, but not the second; the killer of the second is subject to kareth (cutting off, excision). If neither animal has been consecrated and both have been killed beyond the sacred precincts, the flesh of both may be used for food; but the killer of the second is subject to lashes. To prevent an unwitting violation of this prohibition, the cattle-dealer is required to notify the purchaser of the sale of the mother or the offspring for the meat-market. This notice must be given whenever meat is in greater demand than usual, as on the eve of a festival. The duty to cover the blood of ritually killed wild animals or birds (), and the material with which it should be covered. This applies only to the blood of animals which, after being slaughtered, are found to be kosher, and only when the killing has been done on legitimate ground. The prohibition against eating the Gid hanasheh, which is always and everywhere in force, and which extends to consecrated and unconsecrated animals, and to the live young found in a slaughtered mother. The prohibition against mixing milk and meat; "meat" includes any animal flesh except fish and locust. As a rabbinic addition, meat and milk should not be placed near each other on the dining-table. Carcasses and reptiles that communicate impurity by contact; pieces from different parts of a "nebelah" (piece of carrion) are considered as one piece, and if they are collectively of sufficient bulk they render impure any food with which they come in contact. For example, a piece of skin and a piece of bone or sinew, if together equaling an olive in size, render