The Midewiwin is an initiatory society, entered by invitation and instruction and advanced through graded degrees, each with its own teaching, songs and obligations. It is concerned with health, with long life and with the conduct that supports them, and its members are the keepers of a body of knowledge that is transmitted person to person and is not public. Nineteenth century ethnographers obtained songs and teachings from members and printed them. Printing did not make them open, and the atlas states that the lodge exists, what kind of institution it is and that its material is restricted, and reproduces none of it.
The birchbark scrolls belong to that transmission. The figures incised on them are mnemonic, fixing the order of a rite or a song for someone already taught, and unreadable to anyone else. They are frequently described as an Ojibwe writing system, and they are not: they record a sequence, not a language.
The migration account is the piece of Anishinaabe history most often told publicly. It describes a movement westward from the eastern seaboard along a chain of stopping places, prompted by prophecy and completed where food grows on the water, which is the wild rice of the Great Lakes country. It is at once an account of how the people came to be where they are, a charter for the relationship with the rice beds, and an argument about why those beds matter, which is why it is cited in modern disputes over water and mining as well as in ceremony.