Henry Walter Bates ( Leicester , 8 February 1825 â `` London , 16 February 1892 ) was an English biologist who explored the Amazon Rainforest . This naturalist and explorer gave the first scientific account of mimicry in animals . Henry Walter Bates FRS FLS FGS ( Leicester , 8 February 1825 -- London , 16 February 1892 ) was an English naturalist and explorer who gave the first scientific account of mimicry in animals .