Mich. Comp. Laws § 207.18

Sec. 18. Nothing herein contained shall be deemed a waiver or affect the collection of the specific taxes required to be paid by the companies hereby affected, on the first day of July in the year 1909, and previous years, under the general laws upon the property or business of such companies within this state. The existing laws providing for the collection of such specific taxes shall be continued in force until the collection and payment of all taxes levied thereunder for the year 1909 and previous years.