Acetone‐soluble lipids of grasses and other forage plants. II.–general observations on the properties of the lipids with special reference to the yield of fatty acids

Examination of the lipids soluble in acetone at 0° from the leaves of rye‐grass ( Lolium perenne ), cocksfoot ( Dactylis glomerata ), white clover ( Trifolium repens ) and rape ( Brassica napus L.) shows that the yield of fatty acids from these sources when corrected for unsaponifiable matter ranges from 70.5 to 76.5% as compared with 95.6% required for a pure triglyceride calculated as trilinolenin. Further investigation of the cold acetonesoluble lipids of rye‐grass by diffusion in light petroleum through a rubber membrane showed that as in the red clover leaf lipids examined by Weenink 1 most of the fatty acids were combined in a non‐dialysable form as galactolipids. These results support the view that glycerides do not occur to any appreciable extent in leaves but are replaced by galactolipids. Fatty acid analysis showed marked differences between the dialysable lipids (comprising 28.7% of the total acetone‐soluble fraction) and the non‐dialysable lipids in which the linolenic acid is largely concentrated, forming 88% of the total fatty acids.