as to which he is vouched to warranty, whether the tenant has raised that exception  earlier or not he will not be heard, even though the tenant does not hold the whole,  since, though he ought to warrant the whole, he is not bound to give the principal  tenant an escambium greater than the land which the tenant held when the warrantor  loses.1 by judgment, though at the outset the exception would lie for the tenant  against the demandant.
If other exceptions lie for the warrantor which were not at the outset available to the principal tenant, let him put them forward at once.
 If there are exceptions or defences which lie for the warrantor, which did not lie  earlier for the principal tenant, let him put them forward, as that a fine and chirograph  were made in the court of the lord king between the warrantor and the demandant,  or their ancestors, by which fine the demandant or his ancestors remitted  and quitclaimed to the warrantor or his ancestors all the right they had in the land  claimed, or that the demandant's ancestors, or the demandant himself, committed  felony or the like, because of which that land was the escheat of the warrantor or his  ancestors. And so if an acknowledgment and reddition has taken place,2 a gift or sale  with express warranty, or for homage and service, or if the demandant's ancestors  lost that land against the warrantor or his ancestors3 by judgment, or by the grand  assise or the duel. Many such exceptions not available to the principal tenant may lie  for the warrantor, and when he [has prevailed] by such exceptions, or by the duel or  the grand assise, the tenant will retain his seisin and the demandant remain in mercy.
If there is no exception or defence.
 If there is no exception or defence, as the duel or the grand assise, by which the warrantor  can defend his tenant, as will be explained below,4 the tenant will lose the land  claimed and the warrantor will be bound to escambium, to the extent to which he has  the inheritance of him by reason of whom he has been vouched to warranty,5
One is not bound to warrant his father's deed or to give escambium therefor out of his mother's inheritance, nor conversely.
 for no one is bound to warrant the deed of his father or mother or other ancestor,  whose heir he is, or to give escambium out of his own acquisition. Nor ought one to  warrant with respect to his mother's inheritance and give escambium