In the last few years the pathogenesis of icterus neonatorum and kernikterus has aroused renewed interest (Napp and Plotz, 1949; Obrinsky, Allen and Anderson, 1954; Billing, Cole and Lathe, 1954; Meyer, 1956). The discovery by Schmid (1956) and Billing, Cole and Lathe (1957) that bilirubin is excreted in the bile as a glucuronide now makes it possible to reinvestigate this problem more specific...