Explanation #1 (Rashi): Our Mishnah discusses a barrel and flax [near it. Had the flax come from the barrel, surely some would have remained inside.]

Question: Our Mishnah taught Peros!

Answer: Some say that flax is called Peros, like we say (Tanchuma 9) "va'Yavei Kayin mi'Pri ha'Adamah" - he brought flax seed. This is a poor answer.

Explanation #2: Our Mishnah discusses a basket and Peros. Since the Peros are not connected together, had they fallen from the Kli, some would have remained in the Kli;

However, flax sticks together. It is possible that it was in the Kli and fell.

Explanation (R. Chananel): We asked why it says that if some is on the ground, he must announce;

Contradiction (Beraisa): If one found something [without a Siman next to something with a Siman, if] the owner of the [item with a] Siman came and took his [Aveidah], the finder acquired what he is holding, i.e. what is outside, even though there are some Peros inside. This is even if the owner of the Kli says that all [of the Peros] are his.

Consequence: According to this, the text says below "in both cases, some remained [in the Kli]."

Implied question: Above, it was obvious that since weight is a Siman, also measure and number are Simanim! (Why must we bring another proof?)

Answer: We want to prove this here from our Mishnah.

Implied question: Above (24a), it says "but if he found two, he must announce", and it does not say "this teaches that Minyan is a Siman"!

Answer #1: It is a Beraisa. It is no stronger than [the Beraisa of] weight.

Answer #2: We could have rejected that [only if the loser says] the number and that they were on a string, it is a Siman!

Explanation: If Minyan is a Siman, since they are like a tower, we know that they were placed. Two do not suffice [for a Siman], for he announces coins. (A liar would guess that there were two. However, two like a tower is Derech Hinua'ach.)

Question: However, if Makom is a Siman, even if two are like a tower [he should announce, for] we know that this was Derech Hinua'ach!

If [you will say that] with two, even if they are like a tower, we do not know that this was Derech Hinua'ach, for perhaps Derech Nefilah it happened to occur...

If so, below, what was the question "why do we need to say three? Even two suffice!"

Answer: We answered properly that he announces coins. (Alternatively, we could have answered that if there are two, perhaps they fell.)

Explanation: We do not challenge our Mishnah, for we can say that three coins is the explanation of "collections of coins."

Inference: R. Tam derived from here that there is no idolatry called Markulis. Rather, it is Kulis, like we say here;

In general it is called Markulis. This is "in the guise of Kulis", which is an expression of praise. Chachamim switched it to disgrace, an expression of "La'ag v'Keles" (mockery);

"Mar" is "in the guise of", like Mar d'Shechuta (in the guise of a slaughtered animal - Chulin 94a) and Mar d'Parzela (in the guise of brass - Bava Kama 113b).

Explanation: This place is guarded somewhat. However, if he found it in a place that is not guarded at all, surely it is an Aveidah and the owner despaired, since there is no Siman in it;

We do not discuss when it is totally guarded, since the Gemara asks that the knot should be a Siman, i.e. he should take it and announce;

In a place that is [totally] guarded, even if there is a Siman in it, he should not touch it!

Source #1: Our Mishnah teaches that if one found a Kli hidden in a wasteheap, he does not touch it. It discusses when there is a Siman, for it says "if it is exposed, he takes it and announces."

Source #2: Above (24a, a Beraisa) says that if one found an Aveidah, if the majority [in the city] are Yisre'elim, he must announce. If so, it discusses when there is a Siman;

We establish it to discuss when it is hidden in a wasteheap, and they reconsidered to clear it out. If they did not reconsider, he does not touch it.

Explanation (cont.): According to Rava, who says that Makom is a Siman, it mentioned specifically chicks, which can walk, but not other matters [which do not move], for the place is a Siman. He takes it and announces, since [the place] is not totally guarded;

According to Rabah, who says that Makom is not a Siman, it mentioned chicks to teach that even though it is a Safek Hinua'ach, for we can say that they came from elsewhere, he should not touch them.

Explanation: This is like we explained above, perhaps a person hid them

Explanation #1: Some say that this is only when he took them and brought them to his house. We should be concerned lest the owner came meanwhile and did not find what he left there, and he will not return to seek it again. Therefore, he does not return to the place he took it from;

However, if he took them and did not move from there, and saw that the owner did not come meanwhile, he returns it.

Support: The Yerushalmi says so. An episode occurred with R. Aba bar Zavda himself. It says that R. Aba bar Zavda found wine covered in a Chafisah (flask). He took it, and came to ask in the Beis Midrash;

They told him that he did improperly. He suggested that he will return it. They told him not to, lest the owner came and did not find it, and despaired from it. However, if he took it, he does not return it.

Inference: If he only took it, and did not take it anywhere, he does not return it.

Explanation #2: We can explain that here we discuss a Safek Aveidah. Even if the owner intentionally left it there, it seems that he forgot it, for we discuss when it is guarded only somewhat, similar to our Mishnah, for R. Aba discusses our Mishnah.

Therefore, if he took it, he does not return it, for perhaps it is an Aveidah, and the owner forgot it;

Since if he would know that it is an Aveidah, he would be obligated to return it even if he did not pick it up at all, if he knows whose it is, for since it is guarded somewhat, the owner does not despair...

When he picked it up, he is obligated to guard it due to Safek;

Until it comes to the owner, according to Rabah he is a Shomer Chinam, and according to Rav Yosef, he is a Shomer Sachar.

Question: This is unlike Zaken v'Einah l'Fi Kevodo! Rabah said below (30b) that if he hit it, he is obligated [to return it];

We say [about this] in Bava Basra (88a) "I can say that Rabah said so only regarding an animal. He accustomed it to stray, but not regarding other matters!"

Answer: This is because a Zaken is not obligated to return it at all. Therefore, when he returns it to its place, he is not obligated to guard it;

Similarly, a flask (Bava Basra 87b - if Reuven sent his minor son with a flask to buy oil, the grocer) is not liable due to picking it up, for it is Aveidah mi'Da'as (Reuven knowingly gave it to a minor, who is prone to break it). He is not obligated at all to return it.

However, here if he would know that it is an Aveidah, he would take it and return it to the owner, if he knew whose they are;

Now that it is a Safek, if he picked it up, he is obligated to guard it like a true Aveidah.

Support: It connotes like this there in Bava Basra. It says that the flask is an Aveidah mi'Da'as. This implies that if it were not an Aveidah mi'Da'as, it would be fine that he is obligated through picking it up.

The episode in the Yerushalmi, which says "I can say that the owner came and did not find it" discusses when he found it in a totally guarded place. It was not an Aveidah, and there is no Mitzvah to return it;

Therefore, if we did not need to be concerned lest the owner came, he would properly return it.

Support (that the Yerushalmi discusses a totally guarded place): A Stam Chafisah has a Siman. If it were not totally guarded, it was proper to take it! Why did they (people in the Beis Midrash) say that he did improperly?

Observation: A Beraisa below (31a) says that if one found a Talis or ax next to a fence, this is not an Aveidah, and one may not touch it, even if it has a Siman. Also this discusses a guarded place.

Alternatively, there it was intentionally placed, and one may not touch it, even if it has a Siman, for it is normal for workers to leave their Talesim or axes next to the fence of that field [in which they work].

Explanation #3 (of our Gemara - Rashi): He does not return it because no one can give a Siman.

Objection: Obviously, he does not return it anyone if he does not know that he is the owner, since there is no Siman in it! (Rather, "he does not return it" does not refer to people who claim it, rather, to its place.)