Every certificate of stock issued under the provisions of this chapter shall recite that fact upon its face; shall draw interest from date at six percent per annum, unless otherwise agreed in the articles of subscription; and shall be assignable by endorsement, under the hand of the holder thereof, and shall entitle the holder or his assignee to an amount of transportation, either freight or passenger, in his own right or at his request, over any and all parts of the road of such company, its successors, assigns, lessees, or any company operating the same at the time, to an amount equal to the face value thereof and accrued interest, if any, at rates not exceeding those set forth in the recorded statement herein provided for, provided, that such company shall have a right to require one-half of each freight bill, or of the fare for each trip, to be paid in cash, and that the remainder only shall be credited thereon until the amount due and unpaid shall be less than one-eighth thereof after which such holder shall be entitled to freight or passage to an amount equal to the balance due thereon until the same is all paid, when it shall be delivered up to said company, and the rights of such holder thereunder shall cease; provided further, that no assignment of any such certificate shall create any other or greater liability in the assignor than is expressly created by such assignment.