On the application of any proprietor or of any person entitled to become a proprietor of land under separate certificates of title or under any two or more of such documents and on his or her delivering up the duplicates thereof, the Registrar may issue to him or her a single certificate of title for the whole of such land or several certificates as to portions of the land in accordance with the application so far as that may be done consistently with any rules for the time being in force respecting the parcels of land that may be included in one certificate of title; and upon registering any certificate under this section, the Registrar shall cancel and retain the previous certificate, and shall endorse upon it a memorandum setting forth the occasion of the cancellation and referring to the new certificate.