DENTAL CARIES IN THE COTTON EAT(18)

mals (fig. 1) showed that the heavy yellow-brown materialand the deep yellow-brown pigmentation of the lesions associated with the feeding of the 67% sucrose diet (fig. 2) wereprimarily due to inclusion of liver extract in the latter diet.The marked degree of softening of the wide enamel portionof the tooth, the paleness of the lesions and the "bleached"appearance of the teeth (fig. 3) have been found to date to beFig. 1 Mandibular teeth of a cotton rat fed the basal ration containing dextrinin the form of a fine flour, without liver extract.associated with the feeding of diets with a high oatmeal andlow mineral content.DISCUSSIONIt is evident from the experimental procedure used thatthe cotton rats in these studies constantly consumed the samediet as their only source of nutrients for the