Schistosomiasis japonica is one of the famous endemic disease found in east and southeast Asia. It has been a preventing factor against the social and economical development in the endemic areas. From the above reason this disease can be taken up as a subject of regional study from the view point of medical geography. In this paper the writers pointed out, as the first step of their study, a remarkable ubiquity of this disease, and examined some factors controlling its distribution.
This disease is caused by a pathological complex of three factors-human being, intermediate host (a species of snail named Oncornclania hupcnsis nosophora) and Schistosorna japonicum. It is empirically well known that the most important factor among them is the snail. Taking into account the relation between ecological characters of the snail revealed by papers hitherto reported, and environmental conditions in each endemic area, the writers investigated the topography and soil as controlling factors delimiting the distribution of the disease.
The results are as follows:
I. The distribution of the disease is limited only to four or five localities in Japan.
II. Landf orms of the habitats are classified into following three types, with reference to the landform classification of flood areas. They are: (1) Lower deltaic plain; lowlands formed by fine materials such as silt and clay, on which flood water stands deeply for a long period. To this type belong the main endemic areas, i.e. a greater part of the middle basin of the River Chikugo, the Kannabe basin, and basins of the River Tone and the River Arakawa. (2) Lower alluvial fan ; lands which may be flooded by heavy rain, but the water drains soon after the rain. A part of the basin of the River Chikugo and a greater part of the Kôfu basin are classified as this type. (3) Upper alluvial fan; the surface slope is relatively steep and is well drained, having never experienced recent flood. This type is thought to be of an unusual case. A part of the fan formed by the River Midai in the Kôfu basin is the only example.
Thus, in brief, many of the land surfaces of the endemic areas are of the first type, with only a few exceptions. Or, in other word, the distribution pattern of the endemic areas of this disease can be well explained through landform division map by flood-type. However, the largest and the most marked endemic area of Japan, the Kôfu basin, is classified as the second or the third type, suggesting that the flood topography alone may not explain the dis tribution of the disease.
III. By observing in detail each topographic unit of the endemic areas where the snail inhabits are maldistributed, it was found that an important factor affecting such micro land conditions might be the soil. However no precise data concerning the soil of the endemic areas has been shown by the previous reports on this disease. The writers tried to breed snails in the laboratory for the purpose of clarifying soil characters which have influence upon the inhabitation of the snail. Soil samples used for the investigation were collected in many localities ; not only in the Kôfu basin but in other plains and basins of Kantô and Chûbu districts. In them were included artificially mixed soil materials with special texture. Experimental items were: separation of particle-size (by ASK method), measurement of soil texture, determination of humus contents (by Tiurin method) and investigation of differences caused by soil parent materials.
The results obtained are as follows:
(1) Remarkable differences in the numbers of newly hatched snails and in speed of growth and survival rates of youngs were found among samples from, each locality. Especially a sample collected in KOf u habitats showed to be the most suitable for the snail life.

View full abstract

The purpose of this paper is to find out a nature of Japanese cities by means of develo ping a parsimonious set of urban functions.
The study covered variables on population size and structure, population change, economic and social characteristics, and level of education. The areal data unit was mostly based on the Densely Inhabited District (DID). Fifty variables and 189 cities with DID population in 1960 of 30, 000 or over represented the sample. Using Principal Component Analysis, underly ing dimensions between these samples were examined to test the consistency of the compo nent in terms of the parallel sets of data. They are composed of three sets of cities grouped according to regions of Core, Southwestern and Northeastern parts of Japan, and four sets of cities according to the DID population sizes of 30, 000 to 50, 000, 50, 000 to 100, 000, 100, 000 to 250, 000 and 250, 000 or over. A separate component analysis was carried out for each group. The management functions and social status are predominant in all groups except in the case of large cities. As to the group of large cities, urban economic base comes out from the first component.
As a result, the pattern is broadly similar and a study of the factor loadings confirmed that the certain variables are commonly related to the first two components among these samples with substantial correlation of ± 0.300 or over. These variables associated with the first component referring to management functions and social status are namely educational series, white-collar occupations, % in finance (DID), % in service (E.), and population change of 1960-65 for both DID and incorporated cities. Another group of variables forming the second component, which is named as central functions, are sex ratio, and per capita retail and wholesale sales. This study would be a necessary prerequisite to much that can be done toward the interpretation of the system in urbanization of contemporary Japan.
Finally, the author would like to dedicate this paper to celebrate the seventieth birthday of Professor Fumio Tada who has given constructive advices and stimulating criticisms in the field of geographical discipline.

View full abstract

The influences which the construction of the Tsukuba Academic City (The Tsukuba Research and University Town) has exerted upon the agriculture of the region in Ibaraki Prefecture may be summed up as the following two: 1) Despite the facts that the development of the city which is now proceeding has so far shown a poor capacity for the increase in employment and has not decreased the agricultural area significantly, the flow-out of the farmers from the region has recently becoming especially conspicuous. 2) As for the agricultural use of land, the farmers have been still continuing the relatively extensive farming closely dependent on the land aiming at improving the production means, whereas little efforts have been made for the more intensive management such as capital-intensive horticulture or stock raising.
Of the factors which have regulated or specified the farmers' response, we can point out as the most important the change in the labor market centering on Tsuchiura City and the installation enterprises for improving the agricultural management in view of the responding policy of farming. Especially, the latter has given to the agriculture of the region the consolidation of the production means. It has had an effect not only on both land use and labrce, but also on the size of farmers.
The Kashima Industrial Development Area on the stage just after the land purchase around 1968 has shown a specialization trend to a suburban truck farming area through the modernization of cultivation techniques in horticulture. These enterprises, especially irrigation establishments, were designed for the stabilization of agricultural management by dint of getting over the water shortage in the dunes.
Again, the Academic City in Tsukuba is now promoting such enterprises as mentioned above with characteristic features for improving the means of farming production. This policy has been somewhat effective for promoting the flow-out of the farming force from the region without decreasing agricultural profit, and also for increasing the gross agricultural profit. This should be, however, regarded as a policy to foster part-time farmers, because it has only been converting the pure agricultural area with a high rate of full-time farmers into a suburban farming area.

View full abstract

[in Japanese]

View full abstract