Amazingly, the Eucharist was first kept in private houses for the purpose of Holy Communion at home.

As for church, the custom gradually developed of suspending a vessel shaped like a dove somewhere in the church, often over the altar. In the hovering bird, a few hosts, enough to satisfy the pastoral needs of the dying, would be secreted. The priest would lower the dove on a pulley as needed, but it wasn’t a focus of devotion by visitors to the church. It was simply a way of reassuring bishops who were nervous about safeguarding the Eucharist. The dove solution caught on in England and France after Crusaders came in contact with the custom in their travels in the Orthodox
East. —Rev. James Field, Copyright © J. S. Paluch Co.