Investigations on the lipid content of pollen are extremely scarce (reviews: Lunden 1954, 1956; Linskens 1967; Stanley & Linskens 1969) and cover mostly over-all analysis. More recently Ching & Ching (1967) found a total fatty acid content between 0.79 and 1.33% of the dry weight in pollen of some coniferous species, but no acids with uneven carbon numbers. The occurrence of fatty acid methylesters in corn pollen, which can be considered as growth substances (Fukui c.s. 1958), has been confirmed (Fathipour c.s. 1967). As far as the reserve material is concerned, pollen is divided in two groups: fat pollen and starch pollen. Petunia pollen is considered to belong to the type which contains mostly lipids as reserve material. This is confirmed by electron microscopical observations (Sassen 1964), which demonstrated a high amount of lipid droplets in ripe pollen grains.