The memorial meeting, or breaking of bread, is the central weekly act and its form is a direct statement of the movement's ecclesiology. There is no ordained person: a presiding brother conducts, another gives the exhortation, and the roles rotate. In most ecclesias speaking and presiding are limited to brethren, and the role of sisters is one of the community's live internal arguments, handled differently between ecclesias and fellowships. Fellowship is guarded: an ecclesia will admit visitors to the table from ecclesias with which it is in fellowship, and the twentieth-century divisions — Central, Old Paths, Berean, Dawn and others, mostly stemming from disputes in the 1880s and 1920s over the nature of Christ and the atonement — are marked precisely by who may break bread with whom. Some of those breaches have been healed and some have not.