The tabulation and analysis of the data based upon the death certificates aid in measuring the effects of health services and in establishing the need for health programs. As data of the present studies the following items on every death were transcribed from the death certificates : place, date and cause of death, age, sex and the occupation of the head of a household. This series of reports is the result of investigation of the four districts, Eigenji-cho, Kutsuki-mura, Shigaraki-cho and Yogo-mura. The deaths treated here are those who died during 3050 years up to 1965 and total 23, 246. In this report, various statistics of mortality are analyzed, and the following results are obtained : 1) The hygienic effects of social improvement suffered little change during 19151940. While, a marked increase in the average duration of life has occurred since 1949, showing the advances in medical knowledge and hygienic living conditions. 2) It has been made sure that the short life of the people during 19151949 was mainly due to the high death rate of the age-group 04 years. Moreover, it has been found that the relative improvement in mortality has been made not only by the infant and old ages but also by the adult age since 1955. 3) The comparison of various indices: average age of death, proportional mortality indicator, average length of life and rate of survivors at a certain age to the total population etc., provides the ranking of relative longevity among the four districts. 4) Yogo-mura is the most longevous village both in males and females over the whole period.
On the same four districts as in the first report, an analysis of the causes of death classified in 17 main sections (defined by WHO in 1957) has been made. The tabulated data are as follows : ranking of the leading causes of death, cause-specific death rates, cause-specific distribution of the deaths lumped every four years and age specific distribution of deaths by sexes . Furthermore, annual cause-specific distribution of deaths and agespecific distribution of deaths from the main causes are shown in graphs. These data have shown: 1) In each district the ranking of causes of death showed the typical farm village type up to 1940 before the War, particularly in Yogo-mura, but this type has gradually shifted to the standard one of Japan recently. 2) The causes of death the rate of which is decreasing are shown in Sections I, VIII, IX, X and XV. 3) VI is a section which shows the increasing distribution of deaths against the decreasing rate of death, excepting Eigenji-cho. 4) The causes of death the rate of which is increasing are shown in Sections II, VII and XVII, excepting Kutsuki-mura in II. 5) Each district hsa its own type in cause-specific and age-specific distributions of deaths in relation to its social environments and geographical conditions.
In this report, the statistics of infant deaths are analysed and some hygienic subjects and discussed. The results obtained are as follows: 1) After the War, the peak birth rate was reached in the year 1948 with 30-40 births per 1, 000 population. In Eigenji-cho and Shigaraki-chô the rate of birth has more or less been stabilized at 12 by 1957, while in the other districts the rate still shows the tendency to a gentle decline. 2) The infant death rate, which has been calculated since 1947, decreased from 100 per 1, 000 in 1947 to 20 per 1, 000 in 1965, the last year in these data. In Kutsuki-mura this rate is slightly higher. 3) The ratio of infant deaths to the population has remarkably decreased since 1955, but it is still high in Kutsuki-mura. 4) In these districts, over 85 per cent of infant deaths were caused by pneumonia, gastroenteritis and deseases of early infancy. This percentage is somewhat higher than average. 5) The seasonal variation of infant mortality has also been observed. In Eigenji-chô and Shigaraki-chô, there is a greater concentration of deaths in the months of January, February and March. In Kutsuki-mura and Yogo-mura this is the case with the months of March and April. 6) On the months-of-age distribution of infant deaths, the percentage of neonatal deaths is always maximum and becomes larger and larger. 7) The ratio of neonatal deaths to the other infant deaths and the ratio of infant deaths to the deaths of age-group 1-4 years show that the improvement of hygiene and health services has a great influence on infants, but in Kutsuki-mura, utmost efforts must be made to decrease infant deaths.
In the preceding three reports, the duration of life of the people in the four districts, the statistics of the causes of death and those of infant deaths have been analysed . The synthetic results of these analyses are as follows: 1) Up to 1949 social development was not so effective for these districts as to improve mortality explicitly. Owing to the sudden social improvement after the War, a remarkable change in mortality and the principal causes of death occurred in 1950 and a marked decrease in infant mortality occurred in 1955. 2) In each district the effort of prevention is now being focused on neurologic and sensory diseases. With infants, they are gastroenteritis, pneumonia and neonatal diseases. Recently cancer and accidents at ages under 25 have become the leading causes of death. 3) The people of Yogo-mura are most longevious. This is evidently the result of careful health services, especially for infants, and sufficient relaxation during a long winter. 4) Kutsuki-mura has many characteristics in the statistics of mortality . This seems to be attributable to the heavy labor of the men and women in mountains all day long and throughout the year. 5) It must be pointed out that for Kutsuki-mura the number of infant deaths must be decreased by further improving the health services for infants, and that for Shigaraki-cho and Yogo-mura there is some room for improvement in the deaths of 14 years of age. 6) A marked variation by sexes in mortality has not been observed except the large number of male deaths from beriberi and female infant deaths in Kutsuki-mura and the double number of male deaths from accidents in all the districts.
In January, 1959, I made researches on the marriage circle as well as the consanguineous and non-consanguineous marriages of all the 444 couples living in Kobori Section (462 houses), Takatsuki-chô, Ikagun, Shiga Prefecture, which section is famous for the long life of its inhabitants. And in May, 1959, I made the same researches of the 197 couples of random sampling living in Asakuni, Shofuku-ji and Iwane villages (330 houses in total) in Iwane Section, Koseicho, Kogagun, in the same prefecture, which section is famous for the short life of its inhabitants. The following are the conclusions arrived at : 1) On the marriage circle by age-groups of males There is a tendency that the younger the age is, the larger the marriage circle becomes in both sections. As to the marriages between the same villagers, the former section shows 20. 72% and the latter section shows 30.46% and the difference between the two sections is statistically significant at the level of 1.0% (X2=6.71>X20.01=6.63). On the other hand, as to the marriages between the different villagers or townspeople in this prefecture, the former section shows 27.25% and the latter section shows 19.28%, and the difference between the two sections is statistically significant at the level of 5.0% (X2=4.73>X20.05=3.84). Therefore, the marriage circle of the former section is larger than that of the latter. 2) On the consanguineous and non-consanguineous marriage by age-groups of males As to the consanguineous marriage, Kobori Section shows 10.59% and Iwane Section shows 13.71%. The latter section is larger in percentage than the former, though the difference is statistically insignificant. Of the consanguineous marriages, those between cousins are the most numerous in both sections. In the former section 76.6% of the consanguineous marriages (8.11% of all the couples) and in the latter section 77.8% of the same (10.66% of all the couples) are marriages betweencousins. By the age-groups of males, there is no clear distinction between the two sections. 3) On the marriage circle of consanguineous and non-consanguineous marriages The consanguineous marriages of both Kobori and Iwane secions include more marriages between the same villagers than the non-consanguineous ones of them, with statistically significant differences at the level of 1.0% respectively (X= 12.54>X0.01 = 6.63: X2= 15.69>X20.01=6.63), while the non-consanguineous marriages of both Kobori and Iwane sections include more marriages between the different villagers or townspeople in the same prefecture than the consanguineous ones of them, with statistically significant differences at the level of 1.0% respectively (X2 = 9.28>X20.01 = 6.63: X2 = 7.45>X20.01 = 6.63). Therefore, in both sections the circle of consanguineous marriages is far narrower than that of non-consanguineous marriages.
Provincial prevalence of infectious hepatitis is increasing in Japan. Though the germ has been accepted to be a virus (or viruses), it has been able to test by neither virological technique nor immuno-serological method ; the diagnosis of the disease is subjected to the clinical, histopathological or biochemical researchs. As long as it is the infectious disease, however, there may be latent infection or incomplete symptoms, and there may be various types of the disease. Therefore, it may be questionable somehow to forecast the prevalence of such a disease depending on the judgement on the epidemiological phenomena in the early period of the disease. The author was happened fortunately to contribute to treatment of Sashima hepatitis and researched how the epidemiological aspects in the early period was varied depending on the continuous pursue of the disease, and what tests should be employed in the early period of the prevalence. As there are many diseases that cause disturvance of liver such as infectious hepatitis in farm villages in Japan, other factors such as mercury poisoning and filariasis should be considered. The author at first recognized frequent outbreak of liver diseases, and confirmed the infectious hepatitis. Then, the disease was researched as grouping on sex, age and district; there was found out that the levels of positive urine urobilinogen had a relation with the provincial outbreak, and many patients had not been found out even a precise research in the early period. The serum transaminase evaluation was found out to be effective in early research. Though in the group which was thought to be normal, sometimes, presented some patients following the progress of the epidemic, it may be recommended to consider those who showed S-GPT higher than 50(Karmen unit) would be abnormal.