IN Part I (J., 1931, 1216) the synthesis of 3-methylcyclopentane-1: 1-diacetic acid was described. Its mono-and di-bromo-derivatives and the products of their hydrolysis have now been studied with the object of ascertaining the effect of the methylcyclopentane ring on the carbon tetrahedral angle on the basis of Thorpe and Ingold's valency deflexion hypothesis.