In traportal as well as systemic venous injection of a corbicula extract causes an appearance of substances, showing a maximum absorption at 260 mμ, in the dog blood plasma obtained from the hepatic and femoral vein immediately after the injection. They were considered as ad enine nucleotides by paper chromatography and known to originate chiefly in the liver by the fact that a higher concentration is reached in the hepatic venous plasma by either route of injection.