Negotiable Instruments Law
Section 49. Transfer without indorsement: effect of.- Where the holder of an instrument payable to his order transfers it for value without indorsing it, the transfer vests in the transferee such title as the transferor had therein, and the transferee acquires, in addition, the right to have the indorsement of the transferor. But for the purpose of determining whether the transferee is a holder in due course, the negotiation takes effect as of the time when the indorsement is actually made.