The surgical department of our hospital, the majority of whose patients consist of farmers and their families, treated 100 cases of the diseases of gall -duct and of pancreas in the past 7 years, and studied their causation, post -operative troubles, etc.
They were classified as: 1) cholelitiasis, 2) cases whose major troubles consisting of gall-duct passage obstruction caused by the pathological changes at the head of pancreas or at papilla duodeni, 3) cholangitis, 4) round worm penetration, 5) dyskinesia, 6) swelling of the peripylic lymph nodes, etc. In half of these cases no stone was pre-sent. Changes in the pancreas and at the papilla duodeni seem to require special attention. In many cases of acute pancreatitis and pancreasnecrosis, pancreasenzyme was found in high concentration in gall-bladders; the fact made the author assume that repeated inflammation might cause cholangitis.
Recurrence and post-operative troubles occurred to 17% of the cases with stones and to 19% of those without stones. Accurate diagnosis and application of appropriate treat-ment worked out on the correct understanding of the cause are most important for the cases in which no stone is present.

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.

With a view to learning the status, on a wide scale, of the new-infection of hookworms in a rural district, the author examined the pupils of lower secondary schools in Ichiharagun, Chiba Prefecture, and obtained the following results: 1. The ratio of hookworm-ova positive cases was as high as 29.7%of all the pupils examined. By sex, it was higher in the male group than in the female group; and farmers'children showed a higher percentage than non-farmers'.
2. The percentage of new-infection was 2.2%at the minimum, 28.0%at the maximum, 12.4%on an average.In the 20 schools of all the 21 examined, percentages were not higher than 20%.And a significant correlation was found between the total infection rate and the rate of new-infection.
3. The rate of new-infection was also higher among the male than among the female examinees. By their family occupation, it was higher among farmers' children.
4. Distribution of different species among the group of people newly infected with hookworms was closely correlated with such distribution picture in the corresponding area.

In Ichihara-gun, Chiba Prefecture, a rural district, two villages where no anti-hookworm measure had hitherto been taken were selected for the study. The inhabitants of these two villages were first given mass anthelmintic treatment twice, but after that no more anti-hookworm measure was taken. In such natural conditions, theconditions of newand re-infection were observed for more than one year's time byway of stool examination.
1. The hookworm egg-positive rates: 82.4% for Itohisa, Miwa-machi, and 41.2% for Nakano, Shitsu-mura. Both species were present, but Necator americanus predominated in either of the two areas.
2. The cumulative rates of new-and re-infection for the whole year: It was higher in Itohisa (36.9%) than in Nakano (8.4%). But, in the two other villages where antihookworm measures had been executed over a long period of time, such rate was extremely low.
3. The seasonal fluctuations of the rates of new-and re-infection: In both of these subject villages it was higher in the warmer season including the wet season, i. e. mid-April to mid-July.
4. Analysis of the rates of new-and re-infection by modesof living: In Itohisa, school children showed a higher rate of new-infection, and the adults of the same area presented the higher rates of both new-infection andre-infection.In Nakano, no significant difference was seen between school children and adults, but one thing to be noted is that the cases of conversion to positive among school children were all of them new-infection cases.
5. New-and re-infection rates by sex: No particular difference was recognized in either of the two areas.
6. Classification of new-and re-infection cases by species: In bothof the villages, majority of the cases carried Necator americanus only.

My epidemiological studies on ascaris and hook-worm infection in heavy snowing area, Tamugiyama, Chida, Kamioguni and other villages in Niigata Prefecture, conducted from 1951 to 1955, have revealed the following facts.
1. Incidence of ascaris and hook-worm infection in heavy snowing area did not differ much from the one in non snowing area.
2. Epidemiological studies on ascaris.
a. The average rate of ascaris infection per year in Tamugiyama village was 23%, during the 3 years from 1952 to 1955.
b. The average rate of ascaris infection per year among schoolchildren in Tamugiyama and Kamioguni villages was 60.4% from 1951 to 1952.
c. The seasonal fluctuation of ascaris infection indicated higher ratesfrom harvest time to winter (from October to January), then became lower.
d. By the mass treatment conducted in every winter, the incidence of ascaris infection gradually decreased from 54% in 1952 to 35% in 1955.
3. Epidemiological studies on hook-worms.
a. Both species of hook-worms were found; however, Ancylostoma duodenale Dubini predominated in Niigata Prefecture, especially in snowy areas.
b. By the mass treatment conducted in every winter, the incidence of hook-worm infection decreased rapidly, from 52% in 1952 to 21% in 1955.
4. By these various investigations, I found out that the speed of ascaris and hook-worminfection (how soon reinfection occurred) was lower in heavy snowing area than those in non snowing area.