The Legality of the Federal Reserve System

The U.S. Constitution states in Article I, Section 1:

All legislative powers herein granted shall be vested in a Congress of the United States, which shall consist of a Senate and House of Representatives.

So how come the Federal Reserve (Fed), FDIC SEC, etc can make rules by way of regulations as well as adjudicate disputes?

The following document presents a critical review of the legal basis of the Federal Reserve System.