Injections of an alkaline extract of the anterior lobe of beef pituitary produced a prolonged acceleration of growth in rats and a temporary increase in weight of goldfish. A comparable extract of salmon pituitaries (Oncorhynchus tshawytscha) had no effect on growth of rats but produced a slight temporary increase in growth of goldfish. Negative effects of salmon extracts on rats are considered significant, but all effects on goldfish are questioned since the extracts were not free of toxicity.