A method of divination that was practiced by the ancient Celts who kept certain white horses in consecrated groves. They were made to walk immediately behind the sacred car and auguries were made from the observations of their movements.

The ancient Germans kept similar animals in their temples. If during times of hostilities these steeds departed crossing the threshold with their left forefoot, the presage was regarded as evil and the battle was called off. A.G.H.

Source: 9.