No such corporation shall commence the business of insurance until at least three hundred persons have subscribed in writing to be insured therein in the aggregate amount of at least three hundred thousand dollars, and have each paid in two per cent on the amount of the insurance severally subscribed for in cash, which is deposited in bank to the credit of the mortuary fund, in trust for the beneficiaries, and the commissioner has certified that it has complied with the provisions of this article and is authorized to transact business.