what is the missionary society?

Aunt Alexandra has ladies over for a meeting of the Missionary Society of Maycomb, and keeps Scout in attendance in order for her to learn to be a lady. The women discuss the plight of the Mruna people, a non-Christian group in Africa who are said to live in squalor and are being converted thanks to the efforts of a missionary named J. Grimes Everett. Scout doesn't enjoy being around women but does her best to take part.