The Board of Corrections must receive into the penitentiary, on the written order of the Governor, any convict whose sentence has been commuted, according to law, to imprisonment in the penitentiary, and must confine such person according to the terms of the commutation and the rules and regulations established by law; and, if the Governor shall so direct, the cost of conviction in such case must be paid as in case of sentence to imprisonment in the penitentiary.