1) THE LOWER LIMIT OF THE TRACHEA
OPINIONS: Rebbi Chiya bar Yosef says, "All of the neck is valid for Shechitah, from the Taba'as ha'Gedolah (the cricoid cartilage, or the uppermost ring around the trachea) until the lower 'wings of the lungs.'" Rava comments that the "lower" wings of the lungs actually refer to the upper ones, which are "lower" when the animal is suspended by its hind legs. RASHI writes that the "wings of the lungs" refer to the "Onei Re'ah," the upper lobes of the lung, into which the trachea enters. (See ARUCH, who defines "Kanfei" as "edges" or "borders," as in Yeshayah 24:16, "Kanfei ha'Aretz.")
Rava maintains that the lower limit of the trachea that is valid for Shechitah is determined by the lowest part that protrudes when the animal extends its neck when it eats, as long as the extension of the neck is not forced ("she'Lo Te'enas"). Since Rava does not permit Shechitah to be done lower than the part of the trachea that protrudes during feeding, he must explain that the "lower wings of the lungs" refer to the upper lobes (which are "lower" when the animal is upside down). Rava does not permit Shechitah lower than the lobes at the top of the lung. Rav Chanina (or Rav Chananya) asks what the Halachah is (with regard to cutting the trachea at the lowest point that protrudes) if an animal "forced itself." The Gemara leaves his question unanswered (and, accordingly, one must act stringently; TAZ YD 20:3).
What is the meaning of "she'Lo Te'enas" -- as long as the extension of the neck is "not forced"?
(a) RASHI (DH she'Lo Te'enas) explains that the extension of the trachea must not be forced by a person pulling the Simanim out of the chest. Rashi apparently reads the words "she'Lo Te'enas" (literally, "it shall not force") as "she'Lo Te'anes" ("it shall not be forced"). (Perhaps Rashi's Girsa included a "Yud" in the word "Te'anes.") The passive form of the verb implies that the extension of the neck, and subsequent protrusion of the trachea, should not be forced by a person (see PRI MEGADIM to YD 20:1). Accordingly, Rava is saying that one may not cut the protrusion of the trachea that comes about by a person forcing the animal to extend its neck, and Rav Chanina asks whether one may cut the protrusion of the trachea that comes about as a result of the animal forcing its own neck out.
If Rava is using the active form of the verb ("Te'enas"), then that implies that the animal itself should not force the extension of its own neck. This, however, cannot be the correct text, because according to this text Rava would be stating the Halachah which the Gemara immediately afterwards leaves as an unresolved doubt.
The PRI MEGADIM summarizes the different Halachic conclusions according to Rashi. According to Rashi, there are three Halachos:
1. The part of the trachea that protrudes when the animal stretches its neck to eat is certainly fit for Shechitah. This includes even the part that protrudes when the animal stretches its neck to reach a vegetable in a pit (this is in contrast to Tosfos, who maintains that this case is the question of Rav Chanina and the Halachah is left in doubt).
2. The part of the trachea that protrudes when the animal (and not a person) extends its neck at the time of Shechitah is Rav Chanina's question that is left unresolved.
3. The part of the trachea that protrudes only when a person forces the animal to extend its neck is certainly unfit for Shechitah.
Accordingly, the Halachah of Rebbi Yochanan and Reish Lakish cited by the Gemara afterwards -- that the area of the Simanim that protrudes when the Shochet forces them out is unfit for Shechitah -- is exactly the same Halachah that Rava states (that the area that protrudes as a result of a person forcing the animal to extend its neck is unfit for Shechitah).
(b) TOSFOS (DH Ansah) disagrees with Rashi's explanation. Rav Chanina is not asking about an animal that forces its neck out at the time of Shechitah. Rather, he is asking about an animal that forces its neck to stretch far in order to eat a vegetable that it finds in a pit. The TAZ (YD 20:3) explains that Tosfos does not explain, as Rashi does, that Rav Chanina is asking about the part of the trachea that protrudes when the animal forces its neck to extend at the time of Shechitah, because Rava explains that the lower limit is where the trachea protrudes when the animal stretches its neck to eat, and not at the time of Shechitah.
According to Tosfos, Rav Chanina is asking that when Rava says that the lower limit is where the trachea protrudes when the animal stretches its neck to eat, does he mean that the animal stretches its neck very far or only an average length?
The PRI MEGADIM summarizes the different Halachic conclusions according to Tosfos. Tosfos understands that Rebbi Yochanan and Reish Lakish are not teaching the same Halachah as Rava. According to Tosfos, there are four Halachos:
1. The part of the trachea that protrudes normally when the animal eats is certainly fit for Shechitah.
2. The part of the trachea that protrudes when the animal (and not a person) extends its neck at the time of Shechitah is certainly not fit for Shechitah. (This is the ruling of Rava.)
3. The part of the trachea that protrudes when the animal stretches its neck to reach a vegetable in a pit is Rav Chanina's question that is left unresolved.
4. Rebbi Yochanan and Reish Lakish rule that when a person pulls out the trachea, the area that he exposes is certainly unfit for Shechitah. Rava, who lived later, added that even if the animal stretches out its head on its own at the time of Shechitah, the area of the trachea that protrudes is unfit for Shechitah. (D. BLOOM)
2) SPINAL MARROW THAT IS MISSING
QUESTION: The Gemara discusses various deficiencies that might be found in an animal's spinal cord. Rebbi, in the Beraisa, states that when the majority of the spinal cord is cut, the animal is a Tereifah. Nivli says in the name of Rav Huna that the majority to which Rebbi refers is the majority of the membrane (the protective encasement) of the spinal cord. If only the majority of the marrow inside the spinal cord was cut, the animal is not a Tereifah.
Rebbi Yehoshua ben Levi says that "Nismarech" and "Nismasmes" are Tereifos. "Nismarech" means that the marrow inside the spinal cord liquefied, such that if the cord would be pierced all of the marrow would spill out. "Nismasmes" means that the marrow has not become so liquidy that it resembles water, but it has become soft and clear enough such that if one holds the spinal cord and leaves some of the cord protruding from his hand, the cord will bend over and fall down due to the lack of solidity of the marrow inside.
Bei Rav rules that while "Nismasmes" is a Tereifah, "Nismazmez" is Kosher. RASHI (DH Nismazmez) explains that "Nismazmez" means that some of the marrow has disappeared from the cord, and the space it occupied remains empty.
Why does Rashi say that the animal is Kosher only when some of the marrow was removed from the spinal cord? The animal should be Kosher even when all of the marrow was removed!
Moreover, why does Rashi mention only with regard to "Nismazmez" that the animal is Kosher when only a small amount of marrow is missing? When only a small amount is missing, the animal should be Kosher even in the other cases of "Nismarech" and "Nismasmes"!
ANSWER: The SHULCHAN ARUCH (YD 32:4) writes, "When only a small amount of the marrow in the spinal cord is missing and its place is empty, the animal is Kosher." The SHACH (32:6) comments that the reason why it is Kosher when a small amount is missing is that when a large amount is missing, the spinal cord would not be able to support itself when held up, and it would fall over.
Regarding "Nismasmes," no distinction is made between a small amount or a large amount, because once a small amount of marrow reaches the state of being soft and clear ("Nismasmes"), the entire contents of the spinal cord will inevitably deteriorate to the same condition as well.
The Shach compares this Halachah to an earlier statement of the Shulchan Aruch. The Shulchan Aruch (31:2) writes that if a small amount of brain in the animal has rotted or has been crushed, but the brain membrane is still intact, the animal is Kosher. The Shach states that the amount of deteriorated brain matter that is acceptable before the animal becomes a Tereifah is the same amount of matter in the spinal cord that, when removed, would not cause the spinal cord to fall down.
(It is interesting to note that the Sugya here may be relevant to the contemporary discussion regarding the issue of "brain death" and whether such a condition constitutes Halachic death. RAV MOSHE FEINSTEIN zt'l in IGROS MOSHE (YD 2:146) notes that the Halachah states that if the flesh of the brain is poured inside the membrane like water or wax, the animal is a Tereifah (see Shulchan Aruch YD 31:2). (This is derived by the Rishonim from the case of the Gemara of a man who received a blow on the head and whose condition was compared to the Halachos of the spinal cord. The ROSH writes that we learn from here that "Nismarech" and "Nismasmes" in the head also constitute Tereifos.) However, the Igros Moshe points out that the fact that the brain has ceased to function does not constitute Halachic death, because as long as a person is breathing he is considered alive. Rather, the lack of brain function will cause a later cessation of breathing. (This indeed is the definition of "Tereifah" -- a condition that will lead to death at a later point.) Therefore, it is possible that even though the brain is not functioning, there is a possibility that it will heal, and thus one may pray to Hash-m that such a person recover, since he is considered sick but not dead.) (D. BLOOM)