Cnidaria is a phylum within Kingdom Animalia which consists of hydras, jellies (or jellyfish), sea anemones, and corals. All cnidarians are radially symmetrical, and there are two main radially symmetrical body types.
The stock market crash, on black Tuesday (October 29, 1929) began the Great Depression.
CAUSES OF THE GREAT DEPRESSION: A review of Keynesian theory. To understand the Great Depression, it is important to know the theories of John Maynard Keynes (rhymes with rains). Keynes is known as the father of modern economics because he was the first to accurately describe some of the causes and cures for recessions and depressions.