The subject of carriers is a branch of the larger subject of bailments. On account of its importance, and the many striking differences between the bailments of goods to common carriers and other species of bailments, it is made a separate subject in this work. A bailment to a carrier is, ordinarily, a bailment for mutual benefit, and under the Roman law classification is the locatio operis faciendi mercium vehendarum. Although this is bailment for mutual benefit, the liability of common carriers, exceeds that of the bailee in ordinary bailments for the bailee's sole benefit.