Coca-Cola produced a NATURE STUDY educational series from 1929-1934, that were distributed to educators for visual instruction. There were 8 series of 12 cards making 96 cards for the entire set called "Nature Study Cards" packaged in a sleeve/wrapper.
The original artwork was done by Lynn Bogue Hunt and Mary E. Eaton.
{There is rumored to be a 1960 reprint referenced by only one source}