(Mishnah): Any of the following defects makes an animal a Tereifah:

The Veshet was punctured; the (majority of the width of the) Kaneh was cut; the membrane surrounding the brain was punctured; the heart was punctured (if the puncture reaches to the interior); the spine was broken, and the spinal cord snapped; the liver was totally removed;

The lungs were punctured or are lacking;

R. Shimon says, this is only if the puncture extends to the smaller branches.

A puncture in any of the following: the Kevah (last stomach); the gall bladder; the small intestines; the inner Keres (first stomach);

The majority of the outer Keres was torn;

R. Yehudah says, this is for a small ox. For a large ox, it it only if one Tefach is torn;

The Masas (a middle stomach) or the Beis ha'Kosos (the connection between the Keres and Masas) (if the puncture extends to the outside);

The animal fell from the roof;

Most of the ribs were broken;

An animal was Nidras (scratched and poisoned) by a wolf;

R. Yehudah says, a small animal was Nidras by a wolf, or (even) a large animal was Nidras by a lion.

A small bird was Nidras by a Netz (small hawk or cuckoo?), or a large bird was Nidras by a Gas (large hawk).

The rule is, any injury that will cause an animal to die makes it a Tereifah.

(Gemara - Reish Lakish) Question: Where does the Torah hint at the concept of Tereifah?

Objection: It explicitly says "do not eat the meat of a Tereifah"!

(Clarification of question): Rather, where does the Torah hint that a Tereifah cannot live?

The Seifa implies that a Tereifah cannot live. What is the Tana's source?

Answer: "This is the Chayah that you will eat" implies that a Tereifah, which you may not eat, is not Chai (alive).

Question: What is the source for the opinion that argues, and says that a Tereifah can live?

Answer #1: "This is the Chayah you may eat" implies that there is another Chayah (living animal) that you may not eat, namely a Tereifah.

Our Tana expounds "this" like Tana d'Vei R. Yishmael;

(Tana d'Vei R. Yishmael): "This is the Chayah you may eat" teaches that Hash-m showed Moshe every species and told him which may be eaten.

Question: What is the other Tana's source for this?

Rejection (and answer to Question 2): No, all expound "this" like Tana d'Vei R. Yishmael.

Answer #2: The other Tana learns from a different teaching of Tana d'Vei R. Yishmael;

(Beraisa - Tana d'Vei R. Yishmael): "(To distinguish) between the Chayah that may be eaten and the Chayah that may not be eaten" - there are living animals that may not be eaten, namely, the 18 Tereifos that Hash-m taught to Moshe on Sinai.

Questions: There are Tereifos other than the 18 listed in the Mishnah!

There are another four (the acronym BaShGaR alludes to them) and another seven that Amora'im taught (these will be taught later)!

This is not difficult for the Tana of our Mishnah. He taught some Tereifos, and taught 'the rule is...' to allude to others.

However, Tana d'Vei R. Yishmael says that there are exactly 18!

Question #1: ('Beis' of BaShGaR) A Behemah whose hind legs were cut above the knee is Tereifah! (The Gemara (76a) discusses whether this refers to the higher or lower knee.)

Answer #1: Tana d'Vei R. Yishmael holds like R. Shimon ben Elazar, who says that if the thigh is scalded (at the place of the cut), the animal can live.

Objection: According to Tana d'Vei R. Yishmael, even an animal that can live can be Tereifah!

Answer #2: Rather, Tana d'Vei R. Yishmael holds like R. Shimon ben Elazar, who says that this is not an (injury that makes an animal a) Tereifah.

Question #2: ('Shin' of BaShGaR) If the Shidra (spine) of an animal is lacking, it is Tereifah!

(Mishnah - Beis Shamai): A spine missing two vertebrae is incomplete (it has no Tum'as Ohel);

Beis Hillel say, even if one is missing it is incomplete.

(Rav Yehudah): The same amount missing makes an animal Tereifah.

Answer: Our Mishnah lists punctures in the Masas and Beis ha'Kosos separately. Tana d'Vei R. Yishmael counts them like one. (When we add an incomplete spine, his count totals 18.)

Question #3: (Gimel) Gludah (an animal missing all its skin) is Tereifah.

Answer: Tana d'Vei R. Yishmael holds like R. Meir, who says that this is not a Tereifah.

Question #4: (Reish) ChaRusah (an animal whose lungs dried up) is Tereifah.

Answer: Our Tana listed a punctured gall bladder. He holds like R. Yosi b'Rebbi Yehudah. Tana d'Vei R. Yishmael holds that this is Kosher (and counts Charusah in place of it).

Question #5: There are the seven Amora'ic teachings of Tereifos!

(Rav Masnah): A dislocated hip is Tereifah.

(Rachish bar Papa): An afflicted kidney is Tereifah.

(Rav Avira): Even though a Mishnah teaches that a missing spleen is Kosher, a punctured spleen is Tereifah.

(Rabah bar bar Chanah): If the Kaneh or Veshet (was uprooted, and) is mostly dangling (Rashi; Tosfos - they separated from each other), it is Tereifah.

(Rabah bar bar Shilo): The following are Tereifos:

A rib was uprooted from the spine;

Or, most of the skull was Nichbesah (bruised or crushed);

Or, most of the flesh covering the majority of the Keres (the part not covered by the ribs) was torn.

Answer #1: The Mishnah listed eight cases of punctures. Tana d'Vei R. Yishmael counts them like one, so with these seven teachings, his total is 18.

Question #1: If so, also the two cases of cuts in the Mishnah should count only like one! (If so, his total will be 17)!

Question #2: Rav Avira's case should not add to the count, for also his case is a puncture!

Answer: Above, we said that Tana d'Vei R. Yishmael is Machshir an animal with cut legs and Gludah (to explain why he holds that there are 18 in all). Really, he agrees that these two are Tereifos.