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.
One social consequence of the Great Depression was that there was a notable increase in the birthrate in families of unemployed men. Contrary to popular belief, the Great Depression didn't originate in the United States. It started with the economic collapse of Great Britain, which then caused the American stock market to crash.