S CIEXTI FIC P KOCEEDI KGSSzcmiizary : (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 an& 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. ~~ ~~~ ~~~~ 1 Donnldson, H. H., The Rat, Philadelphia, 1924.In 1925, simultaneously and independently, Loewe of Dorpatl and one of us with collaborators' demonstrated the presence of the female hormone in the circulating blood of females by means of the rodent vaginal spread test.3 Since then, in numerous publications we have attempted to simplify and standardize the method of extracting and testing human blood for the female sex h~r m o n e .~ Among other applications we advocated the use of this test to determine the sex of pseudo-hermaphroditic inchiduals in whom we regarded a positive reaction, appearing cyclically, as a proof of the presence of functioning ovaries and feminine sex.5 Our preliminary work had shown that large quantities of Imll's blood (150-100 cc.) gave a negative reaction when extracted by our method. The same applied to concentrated lipoid, HCI, saline and watery extracts of bull's testes, as well as extracts of the hypophysis, thyroid and adrenal, liver, muscle, various proteins, etc.6 The work of Dohrn,' who claimed to have obtained a positive reaction with male urine first called our attention to the possible non-specificity of the Allen and Doisy reaction. After our investigation on male bloods had been completed, the short article of Hirsch,' who used our method,
