The author obtained by door-to-door visits the actual incidence of illness among the entire population of Naguri-mura, Saitama prefecture, a village where forest management is their main occupation, during the month of August, 1957 (the then population consisting of 3401 persons) and of May, 1958 (3290 persons). With a view to confirming the authenticity of the data the author obtained by his personal inquiry, he concurrently conducted another investigation of the same subject on the basis of the medical records of the people's health insurance and other kinds of insurances. A comparative study conducted on the results of the above-mentioned two investigations is concluded as follows.
1. Reports on the visits to doctors obtained by the personal inquiry and the results of investigation based on medical records showed about 80% level of congruity on the occasion of the August investigation which was carried out without any previous notice, and about 93% level of congruity at the next May investigation when the villagers were given special instruction and also got more or less familiar with it.
2. Agreement in the names of diseases reported at the personal inquiry and given in the medical records was 63% level for the August investigation and 80% level for the May investigation; the rates of the females were always 10-7% lower than those of the males.
3. About 10% of the cases failed to give correct names of their illness on account of the dim concept they had in regard to the nature of diseases.
4. Those who reported to have consulted doctors while they actually had not turned out to be 17% in the August investigation and 14% in the May investigation-no remarkable difference was obtained.
5. Those who replied as perfectly healthy although in fact found out to have consulted doctors were as many as 37% in the August investigation and 20%in the May investigation.

This is a study on the incidence, during the whole month of May, 1958, of 11 different kinds of symptoms associated with the so-called Nofusho (a kind of farmers' occupational syndrome) among the inhabitants of Naguri-mura, Saitama Prefecture, a village where they make livelihood almost exclusively from forest management. It covered 2099 persons, the entire population of the village excluding the infants less than 9 years of age. The survey was made by means of personal interviews at their own homes. Taking into consideration the outcome of the study on the incidence of diseases conducted concurrently also by means of door-to-door visits, especially paying attention to the cases who were not brought to doctors' attention, the following conclusion was obtained.
1. The incidence of respective symptoms was: stiffness of shoulders 29.4%, lumbago. 20.6%, joint pain 14.2%, pyrosis 13.0%, paraesthesia 12.2%, vertigo 11.5%, nocturia 11.0%, cold limbs 8.9%, and so on.
2. Those who complained one or more symptoms associated with Nofusho turned out to be 50.0% in males and 55.1% in females.
3. Tentatively classifying those who had 3 or more symptoms as Naushei cases, the incidence of Nausho was 18.6% in males and 22.4% in females-i. e. more common in females.
4. The total number of days within the month on which those on and above 40 years of age actually suffered from such symptoms were: not more than 5 days with half of the patients, and their sufferings were deemed as temporary, but in case of the remaining half, they continued for more than 20 days.

The author conducted an investigation into the incidence of illness in the whole population of Naguri-mura, Saitama Prefecture, by making door-to-door visits.Investigation was made twice, in August, 1957 (covering 3401 population)and in May, 1958 (covering 3290 population), taking a whole month respectively.The materials thus obtained were adjusted in consideration of the results of another investigation of similar kind concurrently conducted on the basis of medical records.The findings adjusted in this way were made to represent the authentic total amount of diseases in respective months, and were then subjected to various analyses.Total cases were classified into four categories according to whether or not they turned up during the respective periods of investigation, and according to whether or not they were healed, moved to other doctors or died during the same periods.In this way analyzing the incidence of illness in this village from static and dynamic standpoints, the following results were obtained.
1. The total number of cases was 1444 in August and 865 in May according to houseto-house inquiry, but the authentic numbers obtained after correction in the light of the medical records were 1605 in August and 958 in May.
2. Ratio of prevalence was 34.3% in August and 18.1% in May incidence was 188.6% in August and 178.6% in May.
3. The kinds of diseases notable in August were neuralgia, lumbago, cold, gastro-duodenal diseases and wounds, and those of May were conjunctivitis, lumbago, neuralgia, cold, hypertensive diseases, wounds, gastro-duodenal diseases and allergy, according to the order of frequency.
4. Percentages held by healthy families(families whose entire members were free from illness) were 21.3 in August and 38.0 in May.Percentage of families healthy in both periods was 13.0.
5. On the basis of the present investigation it became clear that, in order to grasp the true conditions of health and disease, investigation must be undertaken over and over again in a variety of seasons, taking into consideration seasonal variations, diseases and wounds incidental to farming, conditions of location, etc.