Na acetate-1-C14 (9.55 mc ) was fed, in 3 feedings, to a Single Comb White Leghorn hen. Eggs were collected for 7 days and after sacrificing the hen, 2 large ova were isolated and all smaller ova combined, giving 3 additional fractions. The separate shells, albumens and yolks were dried and converted to CO2 by dry combustion. The CO2 was collected and assayed for radioactivity as BaCO3. Activity was present in all shells, albumens, yolks and ova. Activity of shells was roughly constant except for eggs laid within 24 hrs. after a feeding, when it was higher. Activity range for shells low, egg 1 (4.8 [mu]c); high, egg 4 (33.4 [mu]c). Yolk and albumen activities increased with time. Activity range for albumen: low, egg 1 (0.2 [mu]c); high, egg 5 (11.3 [mu]c). For yolks: low, egg 1 (1.4 [mu]c); high, egg 7 (113.6 [mu]c). Yolk 5 showed irregular, low activity which may be due to error in marking or combustion. This is being investigated. Activity recovered: 116.2 [mu]c (1.21%) shells; 43.8 uc (0.46%) in albumens; 495.5 [mu]c (5.18%) in yolks.