On or before February 1 immediately following each Federal census, said board shall reapportion the State for Representatives, and in each instance said board shall file its report with the Secretary of State, setting forth (a) the basis of population adopted for representatives; (b) the number of representatives assigned to each county; whereupon, after 30 days from such filing date, the apportionment thus made shall become effective unless proceedings for revision be instituted in the Supreme Court within said period.

[As amended by Const. Amends. 23 and 45.]