[Factors influencing the changes in liver melanin content of amphibia. I. Effect of breeding temperature].

Frogs caught in winter and kept at summer temperatures, show an increase in the melanic content of the liver. Frogs caught in summer and kept at winter temperatures do not show variations in hepatic melanins with respect to the summer control specimes. This data does not correspond with the natural course of hepatic melanin fluctuations, therefore the causes of the variations are to be sought in factors other than the temperature, one of which could very probably be represented by alimentation.