CERTIORARI TO THE CIRCUIT COURT OF APPEALS FOR THE FOURTH CIRCUIT. No. 469. Argued February 10, 1937. Decided April 12, 1937. 1. A corporation engaged in the business of transporting passengers and express, for hire, between points in the District of Columbia and points in Virginia, held an instrumentality of interstate commerce and subject to provisions of the National Labor Relations Act against discharge of employees because of their membership in a union and their advocacy of collective bargaining