To compare the health standard between inhabitants in an urban and a remote rural districts in Sendai, 313 adults of 40-59 years and 145 school children of 9-12 years were investigated on physical condition, respiratory and circulatory faculty beside inquiry of anamnesis and subjective fatigue symptoms etc. Stature and body weight is lower for the rural district dwellers both in adults and in schoolchildren than for the urban district dwellers. The urban dwellers show larger upper arm circumference (except for adult male) and larger skinfold thickness than the rural dwllers. Although no difference of blood pressure level is found between both population groups, mare ECG and retinal findzngs are confirmed in rural dwellers especially for female. Notwithstanding no difference in vital capacity is found between both popu, lation groups, one second vital capacity in adult is lower for rural dwellers than for urban. Thiss fact seems to be related to the slow wits of the country people. The value of blood pH for adult is significantly higher in the urban dwellers than in the remote rural dwellers. Namely, the blood of the rural people tend to more acid side, compared to that of the urban.
After studying the age distribution of 314 mothers delivered of Down's syndromers in Tokyo during the period from 1938 to 1958, Tsubakihara has reported that the modeof their age found to be above 40 years in the biginning and gradually moved to younger side since 1954, finally being under 30 years from 1954 onward. She ascribed suchtrend to some change of environmental factors which might raise the incidence of Down's syndrome among the children born by younger mothers. The trend of distributionof general maternal age, being left out of consideration by her, might have brought foregoing trend of age distribution of mothers delivered of Down's syndromers. In orderto make sure of this hypothesis, following statistical analysis has been performed. Firstly, using the data reported by several authors, incidence rate for such syndrome among the children by age of mother was calculated. Then, based on these obtained incidence rates and the officially publicated numbers of births by age of mother, expected numbers of births of this syndromers by age of mother were calculated for all Japan and for Tokyo for each year from 1938 to 1958. Results were as follows ; The mode of the age of mothers delivered of Down's syndromers for its expected distribution was found to become younger year after year, showing a quite similar trend as observed by Tsubakihara. As the authors have predicted, the trend of age distributon of mothers delivered of Down's syndromers might be nothing but a matter of course caused by the change of general maternal age distribution.