According to it the Gospel of St.Mark consisted of notes taken down, or rather recollected, from the teaching of Peter.

It was not written 'in order,' but it was an original work in the sense that it was first put in writing by Mark himself, having previously existed only in an oral form.
Does this agree with the facts of the Gospel as it appears to us now?
There is a certain ambiguity as to the phrase 'in order.' We cannot be quite sure what Papias meant by it, but the most natural conclusion seems to be that it meant chronological order.

If so, the statement of Papias seems to be so far borne out that none of the Synoptic Gospels is really in exact chronological order; but, strange to say, if there is any in which an approach to such an order is made, it is precisely this of St.Mark.This appears from a comparison of the three Synoptics.

From the point at which the second Gospel begins, or, in other words, from the Baptism to the Crucifixion, it seems to give the outline that the other two Gospels follow [Endnote 147:1].

If either of them diverges from it for a time it is only to return.