The transferee of a negotiable tangible document of title has a specifically enforceable right to have its transferor supply any necessary indorsement, but the transfer becomes a negotiation only as of the time the indorsement is supplied. (1917, c. 37, s. 43; 1919, c. 65, s. 33; C.S., ss. 315, 4083; 1965, c. 700, s. 1; 2006-112, s. 25.)