he fo pared to those of their sibs are shownin Table 8. Medianheight for controls at the chronological age of 8 years was 122.5 cm for males and 120.0 for females. The skeletal ages for these same children as comparedto those of chronological age peers are shown in Table 9. Subjects +3 and <5 continued to show marked retardation in physical and skeletal growth. Subject +65 has showna spurt in statural growth but continued to lack somewhatin skeletal maturation. Calcium, phosphorus, and protein bound iodine determinations on these children are given in Table 10. Clinically no indication of anydisorder involving mineral metabolism or thyroid function was apparent. LEUKEMIA SURVEY On physical examination no evidence of lym- phadenopathy, spleenomegaly,or othersignsofleukemia were detected. Hematological examinations showed no excessive leukocytosis or increased numbers of immature leukocytes in smears. Baso- phil counts on 4000 leukocvtes on each individual showed noelevation of the basophil counts. Alkaline phosphatase studies* on the blood smears showedthat, although some people had low levels, this finding was not associated with any other findings suggestive of leukemia. STUDIES OF AGING CRITERIA The results of aging criteria studies are plotted in Figures 16 to 32. Individual readings are plotted (circles), and also mean values for each 5year group combining exposed and unexposed people (squares). The trend of each criterion with increasing age is represented bya line of approximatebest fit by eye except in the case of handgrip data for males and females (Figures 30 and 31), which were foundto fit the following formulas: ** Y=60—0.4054 (males); Y=42—0.405A (females) where Y = handgrip in kilograms and A = age. The valuesof the criteria either increase or decrease generally with increasing age. Since the re*We are indebted to Dr. W.C. Moloney and Miss Lila Fliegelman of Boston City Hospital for carrying out the alkaline phos- phatase analysis of blood smears. **Weare grateful to Dr. R. Hinchcliffe of the State University of Iowa for making this observation. sults are similar to those in last year’s report.’ which were given in considerable detail, a lengthy discussion of the various changeswill not be included here. Again, little or no difference was apparent between the exposed and comparison groups of the same age, and therefore no discernible effect of radiation on the aging process was noted. Further statistical analysis is needed for more adequate evaluation of the various parameters and better estimates of biological age scores for individuals. [t is planned to repeat studies of aging criteria every 2 to 3 years. RESIDUAL BETA BURNS Residual skin changes from beta burns sus- tained in 1954 were observed with certainty in about [0 individuals. Most of these residua consisted of mild changes such as varying degrees of pigment alteration giving a mottled or blotchy appearance, sometimes accompanied by hyperkeratosis (increased rugosity) of the skin. Some showed more pronounced changesthan others, such as. atrophy andscarring. Noneoftheresiduallesions showed anygross tendencyto changesassociated with the developmentof chronic radiation dermatitis, nor was there any evidence of malignant changein any ofthelesions. As notedlast vear. in a few cases previously affected areas showed some dark pigmented maculae(lentigo-like). A few appeared as raised moles. It is uncertain whether these lesions are of casual developmentor related to previous exposure. This type of pigmentation was observed less extensively tn the unexposed comparison population. In 10 cases comparison of pictures of these areas taken soon after the appear- ance of lesions in 1954 and then more recently showed that the maculae had developed subsequentto thelesions. (See Figure 33.) Biopsies were not taken this year but may be considered at a later date for study of the histological appearance of the lesions. In Table 11 are listed descriptions of the residual lesions. DENTAL SURVEY A total of 59 school children were examined and treated for caries prevention. Of these, 29 required treatment such asfillings, extractions, and prophylaxis. In the total group 17 showed some evidence of enamel hypoplasia and indication of possible carious lesions in the near future.