EFFECTS OF FALLOUT KADLATION 287 children compared with unexposed children. In an attempt to obtain more accurate birth dates of the children on the 4-year survey, however, it was found that ages of some of the children which were thought to be established were in question. The absence of recorded birth information seriously complicates the determination of the accuracyof given chronological ages and dates of birth. More definitive evalua- tion of the data will be possible whenverification of the birth dates is completed. Detailed geneological and biological histories are being compiled to establish the most probable birth date of each of the children. (Unfortunately the 1958 roentgenograms of the wrist and knee, intended for assessment of osseous maturation, were lost at sea.) Longitudinal studies of incremental growth data and bone maturation studies over the period since exposure will be undertaken when ages of the children are morefirmly establixhed. 3. Ophthalmological Findings Ophthalmological examinations including slit-lamp studies at yearly intervals have not revealed any opacities of the lens that might be associated with irradiation effects. No differences in visual acuity between exposed and unexposed people have been noted. The 3- and 4-year examinations revealed an increase in incidence of pterygium in the exposed population. Arcus senilis and senile cataracts ure of slightly higher incidence in the exposed group but have not shown an increase since exposure. In general most of the Marshallese people examined have superior vision and accommodation compared to our standards. The incidence of glaucoma, myopia, retinal arteriosclerosis, and squint are low. Many of the people have large corneas which will be further studied. 4. Fertilety It has not been possible to show even a temporary sterility on the basis of comparison of frequency of pregnancies in the exposed with the unexposed people. There have been 18 healthy babies born in each of the exposed and unexposed groups since the accident. The pregnancies were distributed fairly evenly over the 4-year period. 5. In Utero Effects and Effects on Pregnancy lour fetuses were irradiated im wfero. One was in thefirst, two in the second, and one in the third trimester. Full-term deliveries resulted in apparently normal babies. There were five miscarriages or babies born dead or dying shortly after birth. Lack of vital statistics in this regard makes it impossible to evaluate these findings with certainty. from comparison with small numbers of unexposed people, however, it does not appear that this numberis excessively high.