Section 25 Punishment of habitual criminals
Section 25. Whoever has been twice convicted of crime and sentenced and committed to prison in this or another state, or once in this and once or more in another state, for terms of not less than three years each, and does not show that he has been pardoned for either crime on the ground that he was innocent, shall, upon conviction of a felony, be considered an habitual criminal and be punished by imprisonment in the state prison for the maximum term provided by law as a penalty for the felony for which he is then to be sentenced.