Mississippi Code Title 5. Legislative Department § 5-1-13

At the hour of twelve o'clock, noon, on the day appointed for the meeting of any regular session of the legislature, the lieutenant-governor shall take the chair in the senate chamber and call the list of senatorial districts in their numerical order. Upon the call of districts the senators-elect therefrom shall present their certificates of election, which shall be prima facie evidence of the right of membership. After the call of districts and the presentation of the certificates, each senator then present shall take the oath of office prescribed by section forty of the constitution, which oath may be administered by the lieutenant-governor. The lieutenant-governor shall cause to be kept, by the secretary of the last senate or other proper person, a record of the proceedings of organization, which shall form a part of the journal of the senate. At any session where the senate has been previously organized, any new senator, on presenting his certificate of election, shall be sworn as in other cases.