The outstanding feature of the drift of population observed in our country of late is understood in terms of the population exodus from rural areas into urban or industrial areas, which brings about. a conspicuous decrease in rural population especially in that of the younger working age bracket. with a view to clarifying an aspect of such wide-ranging migration of population, a study was made in the three remote mountain villages in the Chilbu District, where people are living on an extremely low economic level Investigation conducted for eacch respective economic level revealed an even. abnormally advanced decrease in the population of such younger generation, far advanced than in average rural areas. Thus the unfavorable topogra-phical conditions, lack of cultivating lands, low income, etc.were considered to be responsible for the acceleration of such population exodus. Attention was also drawn to the fact that not only the surplus labor power but even many of the eldest sons. who are the successors to their fathers' occupations are turning to urban areas for employ-ment, threatening the possibility of the replenishment of agricultural labor power and the development of agricultural economics, as well as the future reproduction of population in rural areas.

Examination of feces and deworming were carried out five times every other month between May 1962 to February 1963 in 5 communities (a total of 202 households, 1, 050 inhabitants) of Urakawa, Sakumamachi, Shizuoka Prefecture. After about a year has elapsed, in which no countermeasures were taken, examination of feces was carried out again in January 1964 to study a change in the rate of positivity. Examination was carried out by the cellophane thick layer smear method (values obtained with two sheets).
(1) The rate of positivity for Ascaris eggs ranged from 13.7% to 55.1%, with an average of 28.0% in the initial examination. The rate was higher in two commnities in the mountainous district. By sex and age, the rate was high among infants, school boys and adult females.
(2) A study of the change in the rate of positivity during the two years has shown that the rates of reinfection and new infcction were higher in communities where the rate of positivity was higher in the initial examination, indicating how difficult it is to exterminate Ascaris infection. On the contrary, there was no substantial rise in the rate of positivity in communities where the rate of positivity in the initial examination was under 10%(3 out of 5 communities), even though no countermeasures were taken during the period of one year. This seems to show that it is not required to carry out deworming frequently.
It has been found that the rate of Ascaris infection was lower in communities where persons positive for unfertilized eggs alone accounted for higher percentages among the total of persons positive for Ascaris eggs, there being a marked inverse corelation between persons positive for unfertilized eggs alone and persons positive for all kinds of Ascaris eggs. There has been a marked tendency to familial concentration of Ascaris infection.
(3) The results of the present study have shown that, in taking measures to exterminate Ascaris infection, it is necessary to take into consideration the rate of positivity for Ascaris eggs, the ratio of persons positive for unfertilized Ascaris eggs to persons positive for all kinds of Ascaris eggs, and a tendency to familial concentration of infection in the community.

For the purpose of elucidating the conditions of diabetic patients in rural areas, we have been undertaking some statistical studies in regard to various pathological aspects of diabetic patients being treated at our hospital on the outskirts of Nagoya City, as well as those discovered by diabetes mass examinations. This it to report on the total serum protein values and serum protein fractions (by electrophoresis), measured for the study of protein metabolism.
Group I. Diabetic patients treated at our hospital. No remark-able change was observed in their total serum protein value. In their serum protein fractions, a decrease in albumin value and A/G ratio and a slight increase of α 1-, α 2-, β-and β-globulin values. On the other hand diabetic patients with renal complications showed a decrease in total serum protein value, albumin value and A/G ratio, a slight increase in α 1-, α 2-, and γ-globulin values, and a slight decrease in γ-globulin value.
Group II. Insidious asymptomatic cases discovered by mass examinations. No remarkable change was observed in total serum protein value. A for serum protein fractions, they showed a decrease in albumin value and A/G ratio, and an increase in all glabulin fractions. Furthermore. increase of α 1 fraction was more conspicuous in women, that of α 2 in women and in both sexes with renal complications, that of β-and γ-globulin in women, farmers and those with renal complications.
These findings oriented us farther to the analysis of relation-ship between diabetes mellitus and various environmental factors.

In the five communities of Urakawa, Sakuma-machi, Shizuoka Prefecture, we have taken measures to Prevent and exterminate ascaris infection, and at the same time studied the causes of infection chiefly from the point of view of environmental conditions. The percentages of ascaris egg-carriers showed a significant difference between 1) farmers and non-farmers; 2) families with and without night-soil; 3) amounts of detergent used for cleaning vegetables; 4) persons with and without experience of anthelmintic treatment.
The group of families that showed extremely high rate of positivity were the farmers not provided with night-soil stores, and the farmers provided with such stores showed about the same rate of positivity as non farmers a fact evidences the appreciatng effect of night-soil stores. On the other hand, the rate of positivity among familis that have no night-soil stores but are in the habit of cleaning vegetables with detergent showed no significant difference as compared with the families provided with night-soil storesa positive evidence of the good effect of detergent.

We studied as to whether the incidence of heart diseases in farm areas and in non-farm. areas is different or not. The areas, where the percentage of farm households exceeds 80 per cent of all the households in the areas, were defined by us as the farm areas, and the areas, where the percentage of non-farm households exceeds 80 per cent of all the households in the areas, were defined as the non-farm areas. As heart diseases were the following diseases defined: arteriosclerotic and degenerative heart disease, other heart disease, cardiac arrythmia, arterial disease, venous disease and disease of lymphatic vessel and lymphatic gland. We examined the consultation rates of heart diseases during about two years among all those who carried the National Health Insurance in Toyama Prefecture, comparing farm areas with non-farm areas. When the following two conditions were taken in consideration, such as the difference of the consultation rates of all the diseasesa nd the difference of the incidence of new diseases from those, who consulted doctors, in these two areas, the consultation rates of heart diseases in farm. areas were significantly higher than those in non-farm areas, as well as the consultation rates of hypertension and cerebrovascular disturbances Moreover, we divided all the diseases in 33 categories and studied the differences of the consultation rates of these diseases in farm areas and in non-farm areas, which were also reported.

We investigated, for the consecutive two years of 1964 and 1965, into the incidence and the percentage of hospitalization, etc. of cases of mental diseases in one city and four towns under the jurisdiction of the Fukuyama Health Center in Hiroshima Prefecture, including Fukuyama-shi Kannabe-cho Kamo-cho, Nnmakuma-cho and Utsumi-cho (total population of 219, 781 as of October 1, 1945). The results of sludy are as summarized below:
1) The reported cases-reported through the established procedure of flling and information, examined cases and hospitalized cases were, respectively, 72 cases, 62 cases and 58 cases (93.5%) in 1964, and 86 cases, 83 cases and 76 cases (90.6%) in 1965. The frequency of such reporting in 1965 was highest in May and July.
2) The total cases of mental diseases treated in hospitals during the years 1950 324 or 1.47 percent of the total population.
3) Of these 324 cases, schizophrenic cases held a majority of 252 cases (77.7%), and those that ranked second were alcoholic psychoses and senile psychoses both numbering 14 cases (4.3%).
4) The analysis of such 324 in-patients by age resulted in: 90 cases (27.7%) in the 25-34 age bracket, 83 cases (25.6%) in the 35-44 age bracket and only 1 cases under 14 years of age.
5) The classiflcation of the same cases by the sources of sustenance indicated: 115 cases (35.4%) sustained under Article 29 of the Mental Hygiene Law, 107 cases (33.0%) assisted under the Livelihood Protection Law, 37 cases (11.4%) paid under the National Health Insurance Law, 60 cases (18.5%) under the Health Insurance Law and 5 cases (1.5%) sustained from other sources.
6) Of these 234, the number of cases hospitalized with the public fund under the application of Article 29 of the Mental Hygiene Law and the Livelihood Protection Law was 222, the 126 cases (56.7%) of which were unmarried.And 94 (87.8%) of the 107 patients paid under the Livelihood Protection Law were also the heads of the households.
7) According to the survey conducted as of March 31, 1966, out of such 324 patients 72 cases (22.2%) were discharged within 3 years of hospitalization, and 83 cases (25.6%) had been hospitalized already more than 5 years.
8) According to the 1964 survey, the capacity of mental hospitals per 100, 000 population was 168.3 in Hiroshima Prefecture as a whole, but 127.8 within the jurisdiction of the Fukuyama Health Center, considerably short of the need.