employees "* * * would be immediate and [it] might be catastrophic. We are asked to shut our eyes to the plainest facts of our national life and to deal with the question of direct and indirect effects in an intellectual vacuum. * * * When industries organize themselves on a national scale, making their relation to interstate commerce the dominant factor in their activities, how can it be maintained that their industrial labor relations constitute a forbidden field into which Congress may not enter when it is necessary to protect interstate commerce from the paralyzing consequences of industrial war? We have often said that interstate commerce itself is a practical conception. It is equally true that interferences with that commerce must be appraised by a judgment that does not ignore actual experience."[456] While the act was thus held to be within the constitutional powers of Congress in relation to a productive concern, the interruption of whose business by strike "might be catastrophic," the decision was forthwith held to apply also to two minor concerns;[457] and in a later case the Court stated specifically that "the smallness of the volume of commerce affected in any particular case" is not a material consideration.[458] Moreover, the doctrine of the Jones-Laughlin Case applies equally to "natural" products, to coal mined, to stone quarried, to fruit and vegetables grown.[459] THE FAIR LABOR STANDARDS ACT; THE DARBY CASE In 1938 Congress enacted the Fair Labor Standards Act.[460] The measure prohibits not only the shipment in interstate commerce of goods manufactured by employees whose wages are less than the prescribed minimum or whose weekly hours of labor are greater than the prescribed maximum, but also the employment of workmen in the production of goods for such commerce at other than the prescribed wages and hours. Interstate commerce is defined by the act to mean "trade, commerce, transportation, transmission, or communication among the several States or from any State to any place outside thereof." It was further provided that "for the purposes of this act an employee shall be deemed to have been engaged in the production of goods [that is, for interstate commerce] if such employee was employed * * *, or in any process or occupation necessary to the production thereof, in any State." Sustaining an indictment under the act, a unanimous Court, speaking by Chief Justice Stone, said: "The motive and purpose of the present regulation are plainly to make effective the congressional conception of public policy that interstate commerce should not be made the instrument of competition in the distribution of goods produced under substandard labor conditions, which competition is injurious to the commerce and to the States from and to which commerce flows."[461] In support of the decision the Court invokes Chief Justice Marshall's reading of the necessary and proper clause in McCulloch _v._ Maryland and his reading