THE SIZE OF THE BODY AND THE SIZE OF THE ENVIRONMENT IN THE GROWTH OF TADPOLES

Abstract

Growth in weight was studied from fertilization to metamorphosis in Rana pipiens and R. sylvatica. Under optimal conditions, weight increased logarithmically from hatching for about 2 weeks at 19[degree] C. Thereafter the rate declined, and during metamorphosis the weight decreased. When many individuals were crowded together, the rate of growth declined sooner and more severely, the same effect being produced when the volume of the culture dish was smaller. The foulness of the water had no significant influence within the limits tested, and the stunting effect was found in running water except when the individuals were partitioned from one another. Agitation of the tadpoles likewise inhibited growth. The in-gestion of food per individual was greatly reduced by crowding, though plenty of food was always provided. Quantitative relations were found which expressed the correlation of body size with the physical size of the limited environment.