(R. Ze'ira citing Rabanan): This that you say that we attribute a Shilya to a child (and we are not concerned lest the Shilya was from another fetus), it is because a [pregnant] woman does not become pregnant again (with a second fetus).

Question: We should attribute a Shilya to Nefalim [for this reason, that] a woman does not become pregnant again!

Answer: [We do not, for a Shilya does not separate from the fetus until it is finished. Rather,] I say that she became pregnant with twins, and the Shilya of the Shefir (the Nefel) was dissolved, and the Shefir of this Shilya [was dissolved].

(R. Ze'ira citing Rav Yehudah citing Rav): We attribute a Shilya to a child until three days. A child does not delay [coming out] at all after its colleague (twin).

(R. Ze'ira): The one who said this, he said [also] this. They do not argue!

Note: There is an implied question. The first teaching implies that if they came out more than three days apart, we are concerned lest there was another child, and there was a delay of more than three days between them, unlike the latter teaching!

Answer (R. Ba): Rav Yehudah, citing Rav, established this that we say 'we attribute a Shilya to a child until three days' is when the Nefel came out first. This that we say 'a child does not delay at all after its colleague' is when the [viable] child came out first.

Support #1 (R. Mana): This is proper! Those that nature expels them (Nefalim), they leave first. (We explained this like NO'AM YERUSHALMI.)

Support: #2 (R. Yosi bei R. Bun): [If an opening was] opened for what is big (a viable child), it is opened for what is small. If it is opened for what is small, it is not opened for what is big. (If the womb opened for a viable child to leave, also the Nefel would leave. If it opened for the Nefel to leave, the viable child would not leave.)

(R. Yochanan): [Concern that the Shilya was from another fetus] is like R. Shimon, for R. Shimon says, the child dissolved before it left. (Chachamim argue with him only about Tum'as Mes.)

(R. Yochanan): R. Shimon agrees that a Shilya is Metamei his mother Yemei Leidah.

Question: If so (it is considered a child), the house should be Tamei! (The Yerushalmi holds that there is Tum'as Leidah if and only if there is Tum'as Mes, unlike the Bavli.)

Answer (R. Bun bar Chiyah): The case is, it left when it was dissolved.

R. Shimon (to Chachamim): Do you not agree to me that if one takes out the Kli (in which the child is) from the inner house to the outer house, [the outer house] is Tamei?

Chachamim: It is because it mixes (and it dissolves).

R. Shimon: Also this (in the inner house) is as if it mixed.

Question: Kelim that were there at the time [that the fetus left], what is the law?

Answer: We learn from the following Mishnah. R. Eliezer ben Yakov says, if a big animal expelled a cake of blood, it is buried, and it is exempt from Bechorah;

(Beraisa): It is not Metamei through Masa (moving it).

Question: Why is it buried?

Answer: It is to publicize that [the mother] is exempt from Bechorah. (It is not due to Kedushas Bechor, for we say that it dissolved. We explained this like R. MEIR SIMCHAH.)

(R. Yochanan): R. Shimon and R. Eliezer ben Yakov, both of them say the same matter.

Inference: Kelim that were there at the time it left are Tehorim.