thousand nine hundred and eighty, his term of service shall expire upon the expiry or dissolution of the third House of Representatives to expire or be dissolved after that commencement or, if there is an earlier dissolution of the Senate, upon that dissolution. (7.) A senator holding office at the commencement of this section under the first paragraph of section fifteen of this Constitution shall hold office until the expiry or dissolution of the first House of Representatives to expire or be dissolved after that commencement unless, being a senator appointed by the Governor of the State, he is sooner replaced by a person chosen by the Parliament of a State under that paragraph. (8.) For the purposes of the election, in accordance with the second paragraph of section fifteen of this Constitution, of a successor to a senator chosen by the people of a State, before the commencement of this section, for a term expiring after that commencement but whose place became vacant before that commencement, that senator shall be deemed to have been elected for a term expiring at the time when his term would have expired by virtue of sub-section (6.) of this section if his place had not become vacant. (9.) If the Senate was dissolved within six months before the commencement of this section and an election of senators was held before that commencement, this section has effect in relation to the senators chosen at that election as if the reference in sub-section (2.) of this section to the first meeting of the Senate following a dissolution of the Senate were a reference to the first meeting of the Senate following that commencement, and any division of the senators into classes made before that commencement shall be deemed to have been of no effect. The election to fill vacant places shall be made within one year before the places are to become vacant. For the purposes of this section the term of service of a senator shall be taken to begin on the first day of July following the day of his election, except in the cases of the first election and of the election next after any dissolution of the Senate, when it shall be taken to begin on the first day of July preceding the day of his election. Section 15 If the place of a senator becomes vacant before the expiration of