Explanation #1 (Rashi): [They argue about a piece] when it is convoluted.

Objection: If so, "it is not normal to see blood in a piece" means that it is not Dam Nidah. This is unlike "it is not normal to see in a tube"!

There, it is Dam Nidah from the Makor, just it is not normal to see it (for it to leave) in such a way!

Explanation #2 (Tosfos): They argue about a piece like a tube. It is a Chatzitzah between the blood and flesh (wall of the womb);

The first Tana holds that it is normal to see in such a way. Rabanan hold that even though it is Dam Nidah, it is not normal to see in this way.

Implied question: What is the meaning of "this is not Dam Nidah" that Rabanan said?

Answer: It means "this is not Dam Nidah that the Torah was Metamei."

Distinction: However, if the piece was convoluted, also Rabanan are Metamei, since it is Dam Nidah, and it touches her flesh.

Suggestion: He requires a Shi'ur of Chasimas Pi ha'Amah (enough to seal the opening of the Ever), like R. Shimon in Pesachim (67b);

[R. Shimon] holds like R. Noson, who requires Chasimas Pi ha'Amah for a Zav, because it says "Oh Hechtim Besaro mi'Zovo", and a Ba'al Keri is equated to a Zav.

Rejection #1: If so, what was the question "this (a Shi'ur) implies that he is (becomes Tamei due) to Noge'a (the semen touches him when it leaves his Ever. It is not because he had an emission. The same applies if he touches another's semen!) If so, it should not be Soser Zivah (a Zav, who must count seven clean days without Zivah, should be able to count a day on which he saw Keri)!"?

Since [a Ba'al Keri] is equated to a Zav, it is proper that it is Soser! How can we infer that he is [Tamei due to] Noge'a? (Perhaps it is due to his emission. We require a Shi'ur, due to the Hekesh to a Zav!)

Rejection #2: If he holds like R. Shimon, what was Rav Huna's question "he himself [is Tamei only from Chasimas Pi ha'Amah", and so much will not come out through a chip]? (Piskei Nidah says that this rejection was mistakenly copied to here. Tosfos says so below, in the coming Dibur, which is really part of this Dibur.)

Through a chip, one can see much more than Chasimas Pi ha'Amah!

Explanation: Rather, he holds like the Mishnah below (40a) that any amount of Zov and semen are Metamei;

He says that it must touch Chasimas Pi ha'Amah, because Tum'as Beis ha'Starim (touching a covered part of his body) is not Metamei;

Note: It seems that Tosfos explains that Chasimas Pi ha'Amah does not mean enough to seal the opening. Rather, it is the end of the Ever, for this is external. If the chip is a hollow tube, the semen never touches the Ever externally. Alternatively, one could extract a tiny drop of semen clinging to a very thin chip without touching the Ever externally, e.g. the chip rests on end of the opening, and the drop does not fill the opening.

Therefore, [Rabah] asked that since [you Rav Huna hold that] he is Noge'a, for you are Metaher through a chip, until it touches the opening of the Ever, if so, it should not be Soser Zivah!

Question: What is the Makshan's source that Rav Huna does not require Chasimas Pi ha'Amah like R. Shimon? (Maharam - this is a continuation of the previous Dibur. The words Lemeimra d'Noge'a Havi should be deleted.)

Answer #1: Since he said "we already know this, for he himself is Tamei only from Chasimas Pi ha'Amah", and he did not say "like the Shi'ur of Chasimah", and also he did not say that he is equated to a Zav...

This shows that he did not mention [Chasimas Pi ha'Amah] for the Shi'ur. Rather, it is for touching [the end of the Ever, which is external].

Answer #2: Also, if he holds like R. Shimon, why did Rav Huna ask "we already know this, for he himself [is Tamei only from Chasimas Pi ha'Amah]"? Through a chip, one can see much more than Chasimas Pi ha'Amah!

Question: If he is [Tamei due to] Noge'a, if so, according to the opinion (below, 43b) that one who sees or touches any amount [becomes Tamei], why did the Torah need to write about one who sees?

Answer: Since it wrote about one who sees, we expound in Pesachim (66) [since the Torah did not write only] "Zav", [rather,] "v'Chol Zav" to include a Ba'al Keri, that he is expelled from two Machanos (also Machaneh Levi)...

We apply this only to Ro'eh (one who sees Keri), but not to Noge'a (one who only touches it).

Consequence: [Rav Huna's opinion] affects what we say here, that even Ro'eh is Tamei only due to Noge'a. Even Ro'eh is Tamei only when it touches him externally.

Question: What is the source that he is [Tamei due to] Noge'a? We should learn from the fact that the Torah is more stringent [about one who sees] regarding expulsion from Machanos. This shows that [he is Tamei due to] Ro'eh!

Strengthening of question: The Gemara wanted to say so below (42a) regarding a woman who emits [her husband's] semen that she is Ro'eh, since the Torah warned against a Ba'al Keri at Matan Torah (and forbade Bi'ah three days in advance, lest a woman emit semen. There was no Isur to touch Tum'ah. We must say that emitting semen is like Ro'eh!)

Answer #1: We learn that he is Noge'a, since he is equated to Noge'a. We include Noge'a from "Oh Ish [Asher Yiga b'Chol Sheretz]..." (below, 43b);

Answer #2: Also, that verse itself equates [a Ba'al Keri, which we learn from "Oh Ish"] to [one who touched a dead] Sheretz.

Question: Why did the Torah write about Noge'a? We already know this from "veha'Beged Asher Yihyeh Alav Shichvas Zera"! (Just like semen is Metamei garments, it is Metamei people.)

Answer: We cannot learn about a person from a garment, for one who carries the Neveilah of an animal is Metamei garments on him, even if he is not wearing them, but he is not Metamei a person, even if he is on him.

Support: It says so in Bava Basra (9b) regarding the immature [Chacham] who perverted the ways of his mother. (From this law of Neveilah, Rav Achdevoy bar Ami refuted Rav Sheshes' proof that since a Metzora in Yemei Sifro is Metamei clothing, he makes people Tamei.)

Question: Below (42a) we say that according to Rabanan who argue with R. Shimon, even a woman who emits is Ro'eh, therefore it is Metamei her internally like externally;

Even R. Shimon argues only about a woman who emits, that it is not Metamei her internally like externally, but it connotes that [he agrees that] a Ba'al Keri is Ro'eh, for we do not find that they argue [about a Ba'al Keri]!

Answer: Rav Huna holds like R. Shimon. He holds that even a Ba'al Keri is Noge'a;

If he were Ro'eh, even regarding a woman who emits, he would have explained to be Metamei her internally like externally.

Also Rabanan, perhaps they consider only a woman who emits to be Ro'eh, and she is Metamei internally like externally, because we find that for Tum'as Nidah and Zavah, she becomes Teme'ah internally like externally;

However, one who has Bi'ah with her (i.e. a man who ejaculates), we do not find Tum'ah internally like externally. He is not Ro'eh.

Possibility #1: However, R. Elazar b'Rebbi Shimon argues. He says below (43b) that any amount of Shichvas Zera is Metamei one who sees, and ka'Adashah (a lentil's worth) is Metamei Noge'a;

Inference: Since he distinguishes, this shows that he holds that he is Ro'eh.

Possibility #2: Alternatively, [he is Noge'a]. There is different, for he learns the reason from a verse.

Question #1: (The Makshan holds that he is Ro'eh.) We should challenge him from the Mishnah in Kelim (1:1), which teaches that Sheretz and Shichvas Zera are Avos ha'Tum'ah, but it does not teach a Ba'al Keri!

Question #2: A Mishnah in Zavim (5:11) teaches that a Ba'al Keri is like one who touched a Sheretz. This shows that he is Noge'a, for he is only a Rishon l'Tum'ah!

Answer: Perhaps even [if he is] Ro'eh, a Drashah teaches that he is not an Av ha'Tum'ah.

Explanation: This is the reason why R. Yehoshua holds that a Zav's semen has Tum'as Masa.

Question: Why don't we require a verse there, like we do here?

Answer (R. Chananel): There, we discuss when he saw Zivos during the day. Then, there is much Zivah, and R. Yehoshua holds that it is impossible that his semen does not have intact drops of Zivah;

R. Eliezer, who argues with him in Bava Kama (25a), and says that it does not have Tum'as Masa, agrees that it is impossible not to have drops of Zivah;

Even so, he is not Metamei b'Masa, since semen is mixed with it.

Also here, if not for the verse, it would not disqualify even one day.

Question: This is not called dry! For the matters that the Mishnah (below, 54b) says that they are Metamei wet, but not dry...

It taught there that if they can soak and return to how they were, they are Metamei, like it says there! (If so, the answer does not apply to what he asked about.)

Answer #1: In any case we properly resolved the question, since he did not say "Ki Yizov Zov Damah" - [only] what flows [is Metamei].

Answer #2: There, we discuss what was wet, and dried. Therefore, even though they dried, since they can return to how they were, they are Metamei;

Here, we do not ask about what was wet, and dried. Rather, we ask about what was dry from the beginning, and even if it can dissolve in water.

Question: Also Dam Nidah was taught below (54b) with those [matters that must be soaked me'Es la'Es]!

Answer: There we discuss Dam Nidah that fell on a garment and dried very much. Dam Nidah itself is soft.

Question: There we taught a Zav's spit and phlegm, which are soft [and even so, they must be soaked me'Es la'Es]!

Answer: In any case, they are harder than blood. They began to dry several days ago. They normally dry before they come out;

Blood does not normally dry before it leaves the womb.

Question: Below (56a), R. Shimon ben Gamliel says that he puts them in hot water me'Es la'Es;

Why didn't he teach a bigger Chidush, that even if it does not return [to be moist] after 24 hours, only [it would dissolve] through mashing, it is Tamei according to R. Shimon ben Gamliel?

Even regarding blood, he considers [a change through] mashing [to be a reliable sign of Tum'ah], and all the more so regarding a Neveilah and Sheretz, which are hard;

You are forced to say that through mashing, it (blood) is dissolved more than [returning to be moist] through warm water, for even if you will say that Rabanan require me'Es la'Es, through mashing with pressure, Rabanan do not consider it to be blood. (Chidud Halachos did not understand this. Chachamim estimated that a Sheretz that does not return to be moist after soaking for 24 hours is called dry, even if mashing or more soaking would dissolve it. Dam Nidah is Metamei even if it is dry. Soaking and mashing shells, hairs... are to determine whether or not they are Dam Nidah!)

Explanation: We do not ask that R. Yehudah should argue about a hair or shell, for they are small, and Pesichas ha'Kever does not apply to them.

Implied question: Yetzirah is not written regarding Behemos!

Answer: We say in Chulin (71a) that Tahor Behemos are included in Tahor Chayos regarding Yetzirah.

Note: Likewise, Tamei Behemos are included in Tamei Chayos. Tosfos cites the Gemara there. There, it says that the latter inclusion is relevant to which species we may not eat. Surely, they are included also regarding Yetzirah; the Gemara wanted to teach a different law regarding each.

Implied question: We could have mentioned Stam fish, for the verse "va'Yivra Es ha'Taninim" says also "Kol Nefesh Chayah Asher Shartzu ha'Mayim"!

Answer: In mentioned Taninim, for it is adjacent to va'Yivra.

Implied question: Why don't we answer that this is only when there is nothing more similar [but when there is something more similar, we learn from it]? (Rashash asks that the Gemara asked this, "we should learn Yetzirah from Yetzirah!")

Suggestion: The Gemara means that we should learn from both Yetzirah and Beri'ah to be Metamei [miscarriages with the forms of] animals and fish!

Rejection: You are forced to say that the Gezeirah Shavah was received only for one of them, since we say below "we abandon what is free from one side, and learn from what is free from two sides"!

Answer: The question relies primarily on "also [...we learn from what is free from two sides]."

Question: This is astounding! Did he not know that ["Es Kol Remes ha'Adamah"] is written regarding land [creatures]? It is written on day six [when animals were created], and this (the verse of Taninim) is written on day five [when fish were created]! (Chasam Sofer - va'Yivra refers only to Tanin [but not to the end of the verse, "v'Es Kol Ohf." If so, where did the Torah mention creation of birds? The Makshan thought that it is included in v'Chol Remes ha'Romes Al ha'Adamah" (even though it is written on day six). If so, Yetzirah (Bereishis 2:19, "va'Yitzer... v'Es Kol Ohf") is extra, to make it free. The Makshan thought that also fish are included in v'Chol Remes ha'Romes Al ha'Adamah", since they grow from what grows on the sea floor. We answer that the verse includes only what is on the dry land.)