The Roman armies which Hannibal encountered at Trebia, Thrasymenus, and Cannae were militia opposed to a standing army. This circumstance, it is probable, contributed more than any other to determine the fate of those battles.

The standing army which Hannibal left behind him in Spain had the like superiority over the militia which the Romans sent to oppose it, and in a few years, under the command of his brother, the younger Hasdrubal, expelled them almost entirely from that country.

Hannibal was ill supplied from home. The Roman militia, being continually in the field, became in the progress of the war a well disciplined and well-exercised standing army, and the superiority of Hannibal grew every day less and less. Hasdrubal judged it necessary to lead the whole, or almost the whole of