29 Table 11 Peripheral Blood and Bone Marrow Findings Subject _ Bone marrow smear Het., % WBC Differential 18 41 6,100 normal Erythroid hyperplasia with increased immature red and myeloid elements. 7 14.4 43 6,500 15% eosin, As in #27. 40 13.6 46 6,600 normal No abnormalities. 50 15.7 46 7,500 normal Changes as in #27 but in less degree. 52 13.8 42 9,700 normal Slight increase in immature red and myeloid elements. 30 10.0 29 7,100 normal As in #52. 53 13.2 38 7,900 normal Normal. 66 13.6 40 6,400 normal Normal. 80 14.4 44 9,100 normal Erythroid and myeloid immaturity. No. 27 Hagb., g ‘ Table 12 Mean Levels of Peripheral Blood Elements of Children of Exposed Parents Compared With Those of Children of Unexposed Parents Plate. (* 10-3) WBC (X 10-3) Neut. (X 1073) Lymph. (X10°3) Mono. Eosin. Baso. (10-3) (X10°3) (x 10°2) Males, <8 yr Of exposed parents S11+t23(15)* 8.744£1.34(15) 4.17+0.87°15) 3.92+1.00(15) 0.15(15) 0.49(15) 0.07(15) Of unexposed parents 451+ 80(29) 10.37%2.55(29) 4.8941.68(29) 4.42+1.50(29) 0.30(29) 0.73(29) 0.40(29) Females, <8 yr Of exposed parents 4734149(19) 10.9842.41(19) 4.7241.47(19) 5.0141.36(19) 0.30(19) 0.84(19) 0.30(19) Of unexposed parents 419+ 97(21) 11.632%2.50(21) 5.3542.16(21) 5.2841.92(21) 0.26(21) 0.70(21) 0.40(21) Het., % Males, <8 yr Of exposed parents Of unexposed parents Females, <8 yr Of exposed parents Of unexposed parents RBC (X 10°*) 38.4+3.0(15) 4562+35(13) Hgb., g Serum protein, g 12.0+0.9(1 5) 36.7+2.5(29) 457+39(28) 11.8%1.0(29) 36.7+2.8(19) 37.82%2.7(21) 4$4+37(17) 458+31(16) 1L.7+1.2(19) 12.2+0.9(21) 7,6(1) “Standard deviation and number of people in group. Comments on Hematological Data The 1962 leukocyte levels in both exposed and unexposed groups were generally slightly lower than last year. The level in the exposed group was about the same as in 1960; no hematological examinations were carried out on the unexposed popu- lation at that time. Fluctuations in mean leukocyte levels from year to year, which have been commented on previously, have been unexplained thus far. In contrast to the lowering of leukocyte levels this year, it was noted that the platelets and erythropoietic elements in all groups were elevated as compared with last year, the platelets having