Payment of a mortgage debt works a discharge or an assignment of the mortgage, as equity may require. Moore v. Beasom, 44 N. H. 215; Rigney v. Lovejoy, 13 N. H. 247, 252; Stantons v. Thompson, 49 N. H. 272, 279; Bacon v. Goodnow, 59 N. H. 415, 417. Whatever may have been the understanding of *438 the plaintiff and the bank, justice requires that the mortgage should be considered as assigned to the plaintiff. Robinson v. Leav itt, 7 N. H. 73, 101; Johnson v. Elliot, 26 N. H. 67, 74; Bank v. Weeks, 59 N. H. 239, 240; Drew v. Rust, 36 N. H. 335, 343. The objection, that if this action is in effect a proceeding to foreclose the mortgage the judgment would apply to a part only of the mortgaged premises, and that the part not included in' the writ would be discharged from the mortgage lien, need not be considered, since the plaintiff may have- leave to amend by including in his declaration the whole of the mortgaged land. The defendants’ right to redeem is conceded by the plaintiff, There will be a conditional judgment for the plaintiff, and the right of Mary Duff to a homestead will be detennined on her petition.

Base discharged.