If the transfer purports to transfer part of the land mentioned in any certificate of title, the transferor shall deliver up the duplicate certificate of title; and the Registrar shall endorse on the original and duplicate certificate a memorandum of the transfer; and the duplicate certificate of title shall be returned endorsed as aforesaid to the transferor; and the Registrar shall make out to the transferee a certificate of title to the land mentioned in the transfer, and whenever required by the proprietor of the untransferred portion shall, upon delivery up for total cancellation of the partially cancelled certificate if title, make out to such proprietor a certificate of title to the untransferred portion; but the Registrar may at his or her discretion instead of returning a partially cancelled certificate to the transferor require the transferor to take out a new certificate for the land still comprised in the partially cancelled certificate.