contracts. One who is bound together with one or more others to fulfill an obligation. He may be jointly, or severally bound. 2. When obligors are jointly and not severally bound to pay a joint debt, they must be sued jointly during their joint lives, and after the death of some of them, the survivors alone can be sued; each is bound to pay the whole debt, having recourse to the others for contribution. Yet an infant co-obligor need not be joined, for his infancy may be replied to a plea of non-joinder in abatement. . 3. When co-obligors are severally bound, each may be sued separately; and in case of the death of any one of them, his executors or administrators may be sued. 4. On payment of the obligation by any one of them, when it was for a joint debt, the payer is entitled to contribution from the other co-obligors.