1. 1. Comparative studies on biliary amylase were done in fish, amphibian, reptile, bird and mammal. 2. 2. Pancreatic amylase is tenfold and eightfold more active in Passer domesticus and Corvus spledens respectively than biliary amylase. 3. 3. Amylase in bile is either absent or with only little activity in carnivore vertebrates. The reducing sugar produced was 4.5 mg and 5.7 mg/100 ml in toad and Calotes respectively. 4. 4. NaCl dependence is pronounced and leads to about 50 per cent increase in activity. 5. 5. Optimum pH 4.9, for amylolytic activity in bile and liver of crow, corresponds with the luminal pH of the duodenum.