Contents

25 September 1987
Vol 237, Issue 4822

About The Cover

The thermogenic inflorescence of Sauromatum guttatum Schott, voodoo lily (right) and its thermographic image (left) on the day of flowering. Each 1°C difference in surface temperature corresponds to a different color. The appendix, upper cylindrical part of the inflorescence, is about 9°C warmer than the rest of the plant. This heating is triggered by salicylic acid which moves into the appendix 1 day before inflorescence unfolding. The heat is used to volatilize putrid-smelling compounds attractive to insect pollinators. See page 1601. [M. E. Nuttall, Photo Services, Du Pont Experimental Station, Wilmington, DE 19898]