the communion of mankind is denied a leper, so it is to one who is excommunicated,  and what is more, every lawful act. An exception lies for the tenant not only because  of the demandant's person, but because of co-heirs and parceners, without whom he  cannot sue, since they have as much right as he who claims, or because not the  demandant but another has the right, or a greater right, so that the demandant  cannot sue without others or cannot sue at all. An exception also lies for the tenant  because of conjunction, as where a husband wishes to sue for his wife's property  without his wife, in which case [he will not be heard without her] any more than she  without him, but the writ does not fall if he [is sued] without his wife, because he may  vouch his wife to warranty, but not conversely.1 An exception also lies for the tenant  against the demandant by reason of a superior whom the matter affects in some  way, as [monks], [who are sometimes] perpetual, sometimes removable, without the  abbot or prior, an abbot or prior2 without the chapter,3 or canons without their bishop  and patron.4 Also the brethren of a religious house without their warden and sometimes  nuns or sisters like the sisters of Buckland, who cannot act without the prior  of the Hospital, in which case the wardens without whom the brethren and sisters  cannot sue must be called to sue. As to the exception of villenage put forward against  a demandant, what ought to be done, in a possessory as well as a proprietary cause,  may be drawn adequately from what was said above in the tractate on the assise of  novel disseisin, where [villenage] is excepted against the assise.5
The exception against the demandant arising from his person.
 An exception lies for a tenant against a demandant arising from the demandant's  own person, a peremptory exception, that he be barred6 from the action forever, on  the ground that he has no right since he is a bastard. It is sometimes raised by way  of an exception, as here said, when it is raised by the tenant, sometimes in place of an  action, when it is put forward by the demandant against the tenant, that he be removed  from possession.7 Hence we must first see how it ought to be raised, [against  whom, by whom, and in what action, and how an answer may be made to it after it  has been raised,]8 how