A woman in Sri Lanka once told me a story. She said that the rate of malaria among the British in Sri Lanka during the 19th century was much higher than in the local population. It was the vases of flowers, she told me. In the British households, they found it absolutely necessary to keep beautiful bunches of cut flowers in vases. These vases of standing water happened also to be perfect breeding grounds for mosquitos. The British were killing themselves with a stubborn sense of aesthetics.