ARUM FAMILY 63 
actually gives off heat, so that the temperature 
inside the blossom is higher than it is outside, 
even when the wind is not blowing. Conse- 
FLOWERS OF SWAMP CABBAGE 
quently it is not strange that the flies seek such 
snug retreats when the sun is hidden by clouds, 
but come out again when it shines once more. 
