The biological function of endosperm is to support the developing and germinatingembryo, and as such is believed to have played an important role forthe evolutionary success of angiosperms. The ontogeny of the endosperm remainedan enigma until the discovery of double fertilization a littlemore thana hundred years ago. Soon thereafter, plant anatomists revealed an unusual patternof development: many types of endosperm go through a syncytial phasebefore becoming cellular. The mechanism underlying the cellularization processof these so-called nuclear endosperms was discovered only recently, andmost of the molecular and developmental biological insight into endospermshas been gained only in the last two decades. To my knowledge, this book isthe first comprehensive treaty dedicated in its entirety to endosperm developmentaland molecular biology.