The provisions of sections 1571 and 1572 of this title shall not apply to any carrier in respect to any seed transported or delivered for transportation in the ordinary course of its business as a carrier: Provided, That such carrier is not engaged in processing or merchandising seed subject to the provisions of this chapter; and such provisions shall not apply to seeds produced by any farmer on his own premises and sold by him directly to the consumer, provided such farmer is not engaged in the business of selling seeds not produced by him: And provided further, That such seeds produced or sold by him when transported or offered for transportation to any State, Territory, or District, shall not be exempted from the provisions of sections 1571 and 1572 of this title unless said seeds shall be in compliance with the operation and effect of the laws of such State, Territory, or District, enacted in the exercise of its police power, to the same extent and in the same manner as though such seed had been produced, sold, offered or exposed for sale in such State, Territory, or District, and shall not be exempted therefrom by reason of being introduced therein in original packages or otherwise: And provided further, That such seeds produced or sold by him are in compliance with the seed laws of the State into which the seed is transported.