The total lipid was extracted from BP8/C3H ascites-sarcoma cells with acetone, light petroleum, pyridine and chloroform-methanol successively. Each extract was treated with mild alkali. The alkali-stable lipids from the pyridine and chloroform-methanol extracts, which included the glycolipids, were fractionated on silicic acid and silica gel G columns. 2. The total yield of glycolipid was about 60 mg./100 g. dry wt. of tumour cells, about 0.4% of the total lipid. Four classes of glycolipid were isolated and characterized as ceramide monohexoside (G1), ceramide dihexoside (G2), ceramide trihexoside (G3) and ceramide hexosaminyltrihexoside (G4). 3. G1, G2, G3 and G4 constituted 55, 21, 9 and 15% of the total glycolipid respectively. 4. G1 was a mixture of ceramide glucoside (70%) and ceramide galactoside. 5. The general structures of the oligosaccharide moieties of G2, G3 and G4 were elucidated by partial acid hydrolysis of the glycolipids with water-soluble polystyrenesulphonic acid. G2 was mostly ceramidelactoside with about 10% of ceramide galactosylgalactoside. G3 and G4 were probably a ceramide digalactosylglucoside and a ceramide N-acetylgalactosaminylgalactosylgalactosylglucoside respectively. 6. The fatty acid compositions of the glycolipids were very similar; lignoceric acid and nervonic acid were the major components and all contained monohydroxy acids in proportions varying from 10 to 25% of the total acids.
