Del. Const. art. II, § 7
The Senate at the first annual session of every new General Assembly shall choose 1 of its members president pro tempore, who shall preside in the absence of the Lieutenant Governor, or in case the latter shall become Governor or while continuing in the exercise of the office of Governor by reason of disability of the Governor. The Senate shall also choose its other officers and in the absence of the Lieutenant Governor and its president pro tempore may, from time to time, as occasion may require, appoint 1 of its members to preside. The House of Representatives at such first annual session shall choose 1 of its members speaker and also choose its other officers, and in the absence of the speaker may from time to time, as occasion may require, appoint 1 of its members to preside.
51 Del. Laws, c. 105 and 52 Del. Laws, c. 21; 53 Del. Laws, c. 379 and 54 Del. Laws, c. 12; 71 Del. Laws, c. 379 and 72 Del. Laws, c. 136; 84 Del. Laws, c. 281 and 85 Del. Laws, c. 5;