An Embryological and Genetical Study of Rana Burnsi Weed

N NATURAL populations of meadow frogs from the north central I states an occasional individual is found that differs markedly in pigmentation from the typical Rana pipiens. The latter has the back, sides, and legs covered with black spots of various sizes and shapes. The exceptional individuals closely resemble pipiens in general form but are completely or nearly devoid of the black spots (fig. These "meadow frogs without spots" have been treated in a variety of ways by taxonomists. DICKERSON (1906) regarded them as a color variety of pipiens and was apparently of the opinion that the condition occurred only in juvenile frogs. In 1922 WEED suggested they be regarded as a distinct species and given the name Rana burnsi. This step was deemed necessary, since both spotted and non-spotted individuals are found together but with no evidence of intergradation. WEED'S species has not been universally accepted. Neither KELLOGG (1932) nor STEJNEGER and BARBOUR (1939) recognize Rana burnsi. Academic treatment of this kind, however, can do little to settle the problem.