(1) Weights of liver and spleen obtained at all months of the year on 499 male and 444 females, healthy, adult ring doves demonstrate that a true sex difference exists. Though the male body weight is slightly larger, the male livers and spleens are smaller, 9.476, and 23.5%, respectively. (2) A true seasonal increase in size of liver and spleen occurs in spring and summer in both sexes (10.4% and 12.0% in 8; 6.1% and 4.3% in 9 9). (3) These changes in spleen and liver are positively correlated with size changes in testis and ovary; and negatively correlated with size changes in the thyroids of these animals.