Abstract
A gradient column of polyvinylpyrrolidone in 10% saline sharply divides the fat particles of alimentary lipemic plasma into 2 groups. The particles of both groups float in isotonic saline, density 1.006. During alimentary lipemia the 2 groups differ in rates of appearance and disappearance, and in fatty acid composition. Evidence is presented that one group consists of particles from thoracic duct chyle; the other group consists of particles originating elsewhere, possibly the liver.