The state of Washington hereby assents to the purposes, terms, provisions and conditions of the grant of money provided in an act of congress approved March 16, 1906, said act being entitled "An Act to provide for an increased annual appropriation for agricultural experiment stations and regulating the expenditure thereof," and having for its purpose the more complete endowment and maintenance of agricultural experiment stations theretofore or thereafter established under an act of congress approved March 2, 1887.