1. In Sen-En manufacturing region, covering 1360. 85 square Kilometers, there are two cities and two towns, Sendai and Shiogama, Tagajo and Shichigahama, respectively. The number of factories in this region amounts 32.2 per cent of the total of Miyagi prefecture. As a matter of fact these factories are agglomerated in the following four districts, namely Nagamachi and Odawara in Sendai, Tagajo and Shiogama port, connected one another by railroads and highways.
2. Before 1935 there were only a few modern factories in the old cities of Sendai and Shiogama. During the wartime, special steel goods, rubber and chemical goods came to be manufactured in Nagamachi. At the same time shipbuilding industry developed in Shiogama port. Later on, an army arsenal was built in Odawara and a navy one in Tagajo. After the war, especially in 1950's, many factories were established in the four districts aboue mentioned, which resulted in the formation of Sen-En manufacturing region. Major products of these new factories include steelcasting, agricultural machinery, electric machinery and appliance, corrugated cardboard, cans and canned foods.
3. The main factors for ohe development of manufacturing in Sen -En region are as bollows; the market of Miyagi and neighboring prefectures; high degree of accessibility by rail road, existence of a port which handles a large amount of fishes, timber and coal; extensive land for industrial use; recent development of a steam power plant; technical guidance by the Tohoku University in Sendai. In addition to them, following political means are considered as powerful factors, namely the city - planning of Sendai regulating the used of land; the factory inducement policy to give every convenience to the establishment of new factories, and the “Sen-En Integrated Development project” improving the locational conditions for industry.

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In the Yoneshiro Valley, Akita Prefecture, the accumulation terraces consisting of pumiceous material are distributed extensively making a noticeable feature of the valley. The author made clear the following facts by his survey of the terraces.
(1) The accumulation terraces which form the middle terraces in the Yoneshiro Valley are distributed from the Hanawa to the Takanosu Basin (Fig. 1, 5). Pumiceous deposits of the terraces are composed of the pumice flow deposits (the Towada pumice flow deposit) and the pumiceous gravels deriving from the deposits. The pumice flow deposits were supplied from the Towada caldera in the first stage of its volcanic activity.
(2) The Towada pumice flow deposits are easily discernible by the survey, and are distributed universally in the environs of the Towada caldera such as the Yoneshiro valley, the Kamikita Plain and the Tsugaru Plain. Therefore, it is effective for the correlation of the landforms in these areas to use the deposits as an indicator.
(3) The accumulation terraces in the Hanawa Basin are covered by volcanic ash erupted from Towada caldera. Archaeological remains of the Jomon Stage, so-called “Oyu stone-circle”, are found on the terrace surface. The chronological relations of the forming process of the terraces to the volcanic ash and the prehistoric remains are shown in Table 1.

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The Erimo sand was named by Dr. Y. Ogasawara in 1941 at Erimo in Hokkaido. In 1957 and 1958, present writer found the Erimo sand distributed widely on the terrace surfaces along the coast of Hidaka.
The volcanic sand of Erimo is deposited on the higher and lower coastal terraces as well as on the higher river terraces along the Hidaka coast. Stratigraphically it continues to the Shikotsu pumice deposit, erupted from the Shikotsu volcano in the late Pleistocene at Bibi and in its neighbourhood. The author examined 34 columnar sections (Fig. 2), and analysed the grain size and heavy mineral composition (Fig. 3, 4). According to his observations, the volcanic sand of Erimo has the same origin as the Shikotsu pumice deposit.
An embedded fossil forest was discovered at Bibi and in its neighbourhood, and its absolute age was decided by C¹⁴ methods. The volcanic sand of Erimo covers the Mammontius bed correlated with the lower terrace deposit at Ogoshi. The abovementioned relations exit also in the south of Tokachi plain. Consequently it is considered that the terraces of Hidaka coast and Tokachi plain are correlated each other geomorphologically.

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The writer studied the changes of the sericulture and the locational factors that in fluenced them in the Yokote basin and set up sericultural regions of the basin (Fig. 6).
The northern margin of the sericulturein Japan is generally aknowledged as the line drawn from southeastern part of the Yokote basin to the Fukuoka area in the northern part of Iwate Prefecture. According to his study, however, the marginal area in the Yokote basin is located in the upper part of the Omono River, such as Yamauchi, Fukuchi and Meiji.
The mulberry fields once distributed extensively on the fans and natural levees in Taisho era (1912-26), are now reduced to the drainage area of the upper tributary of the Mogami Ri ver. The land formerly used as mulberry fields was converted to residence lots, vegetable fields, fruit orchards etc. Their distribution is arranged in the order of landuse intensity in accordance with the distance from Yuzawa city.
There are many factors that influence the development and decline of sericulture. Among them the more important ones are climate, topography, size of arable land, facilities of communication, advance payment system by rural merchants and the farmers' attitude toward agricultural management.

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