The characteristics of animals and beasts were stated in the Torah, but the characteristics of fowl were not stated. The Sages, however, said: Any bird that seizes its food is nonkosher. Any one that has an additional toe, a crop, and its gizzard can be peeled, it is kosher. R’ Eliezer bar Tzadok says: Any bird that parts its toes is nonkosher.

And among locusts: Any one that has four legs, four wings, jointed legs, and its wings cover the greater part of its body. R’ Yose says: And its name must be chagav. And among fish: whatever has a fin and a scale. R’ Yehudah says: Two scales and one fin. These are the scales: those that are fastened to it; and fins: those with which it glides.

[If] an animal is in difficult labor, and the fetus put forth its foreleg and drew it back, it is permissible for eating. [If] it put forth its head, although it drew it back, it is regarded as having been born. [If] one cuts off [part] of the fetus that is in her womb, it is permissible for eating; from the spleen or from the kidneys, it is prohibited to be eaten. This is the general rule: What is [part of] its body is prohibited; what is not [part of] its body is permissible.

[If] an animal is in difficult labor with its first young, one may cut off each limb and throw [it] to the dogs. [If] its greater part comes out, it must be buried, and she is exempted from the law of the firstborn.