305. Persons claiming under the mortgagor.

305.     Persons claiming under the mortgagor.

The following persons claiming under the mortgagor can redeem:


    (1)     an assignee of the equity of redemption, including a volunteer1;


    (2)     a subsequent incumbrancer2;


    (3)     a tenant for years under a lease made subsequent to the mortgage which the mortgagee refuses to confirm3; and


    (4)     a surety on payment by himself or refusal by the principal debtor to discharge the mortgage debt, or if the surety has mortgaged his own estate as security for the debt4, but not where the surety