It is an essential theory of our constitutional system that the relations between the Union and the States are determined by the Constitution of the United States, and hence that the powers of the government of the one may be neither increased nor diminished (except in the few instances provided for in the Constitution) by the action of the government of the other. How far this theory has been actually embodied in law it is important to inquire in regard to all three functions of government, legislation, jurisdiction, and administration, but the present discussion will be limited to illustrations of the delegation of legislative power by congress to the States. The acts of congress with which we are here concerned form three distinct classes: those involving the concurrent powers of the States which may be exercised in the absence of conflicting congressional legislation; those involving powers of the States which may be exercised only by reason of some positive action of congress; and, last, a class in which there is an adoption of laws of the States as laws of the United States.