The pancreatic content of lecithinase A in man is approximately 10–20 times that in the dog. In contrast, the pancreatic content of lipase is one-half and of amylase one-sixth that of the dog. The rabbit is similar to man in its pancreatic amylase and lipase content, and to the dog in its lecithinase A content. In man the serum lecithinase A increases during acute pancreatitis, paralleling more or less the elevations in serum amylase and lipase. Though individual discrepancies are noted, all three enzymes increase roughly proportionately. During acute pancreatitis in the dog, the serum lecithinase A increases but slightly, in sharp contrast to the elevations in serum amylase and lipase which are greater than in man. Submitted on July 12, 1962