Section 19. The aldermen or selectmen may make regulations consistent with the general laws relative to the exercise of the trade of bootblacking by minors, and to the sale or barter by minors of any goods, wares or merchandise the sale of which is permitted without a license by section seventeen, and may prohibit such trade or such sales, or may require a minor to obtain from them a permit therefor to be issued on terms and conditions prescribed in such regulations; provided, that in the case of girls under the age of eighteen years and of boys under the age of sixteen years the foregoing powers in cities shall be vested in and exercised by the school committee. No permit issued to a minor under this section nor badge issued to him under sections sixty-nine to seventy-three, inclusive, of chapter one hundred and forty-nine shall authorize the sale by a minor of any article, other than those which may be sold without a license under section seventeen, except that a badge so issued may authorize, in addition, the sale of magazines and other periodicals and song sheets, so called. A minor who sells such article or exercises such trade without a permit, if one is required, or who violates the conditions of his permit or any provision of said regulations, shall be punished by a fine of not more than ten dollars.