The result of our investigation by means of more than one hundred borings together with cone penetration tests shows that there are three erosional surfaces under the recent alluvium in the coastal zone of the Nobi alluvial plain.
(1) The upper surface, at the place of 0-10 meters below the present sea-level, can be seen in the southeastern part of the plain. This surface seems to have been an abrasion bench which was formed on and after the middle stage of the Recent.
(2) The medial surface, at the depth of 20-30 meters below the present surface, could have been formed due to river erosion during the late Pleistocene when the sea-level was approximately 40 meters lower than that of the present.
(3) The lower surface can be seen in the western part of the plain, at the place of 40-55 meters below the present sea-level. This surface is the floor of the Kiso pre-Recent entrenched valley system, during the lowest sea-level period in the last glacial stage.
The buried topographic features found in the Nobi Plain, which are in accord with those found in both Tokyo and Yokohama area and Hamamatsu area, are also very much alike to those in the lower Mississippi alluvial valley which was investigated by H. N. Fisk.
Similarities in topographic features in all those areas suggest that those topographic features were controlled by oscillation in sea-level during or after the late Pleistocene. The existence of those topographic feature shows that the sea-level in the late Pleistocene changed by the following process:
(1) After the Pleistocene high sea-level period, the sea-level was lowered to the depth of 30-40 meters below the present sea-level (A Period),
(2) then, the sea-level was lowered again to the lowest level in the late Pleistocene (B. Period.).
Since rejuvenation did not extend to the upper part of the buried tributaries, it is clear that the duration of the deeply entrenched valley was limited to a relatively short period of time. A Period is believed to have been shorter than B Period.

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In this report, the author defines the kind of big wild mammals to four species—Japanese bear (Ursus thibetanus japonicas), antelope (Capricornis crispus), deer (Cervs nippon) and wild boar (Sus scrofa). As the distribution of the first two species is very limited in Kyushu, the author's interest here is inclined to the distribution of the latter two animals. Thus his major problem is why the deer defenseless against the attack of mankind have been keeping greater territory—though the territory is separated in some pieces—than that of the much stouter wild boar.
The major premeise the author has taken here is that, in the densely populated land as in the western part of Japan, the distribution of these large-sized wild mammals are the result of suffering defeat from mankind. In short, the reason of this distribution can be sought, not in natural but in historical factors. This is well-ascertained by documentary records written by some old Japanese herbarists and geographers. Also, the author's data, including these documents, consist of hearings from native hunters, information from investigaters and guide-books, and of his own observations. One of the most valuable resources is the stone monuments which are established by native hunters who hunted one thousand beasts. This custom is prevalent only in the northern part of Kyushu. The dates of these monuments show indirectly the definite dates of the extinct species in their vicinities—the interval of both dates is about half a century in each case.
The general distribution of the big wild mammals in the Northern Kyushu, except its northwestern islands and peninsula (Nagasaki Prefecture), is given in Fig, 1. Since the bigining of the 17th Century, the large-sized, wild mammals have been driven out from the middle part of the Northern Kyushu where lie the Chikugo Plain and the Seburi Hills, to the north-west and to the south-east, In the northwestern part there are no bear nor antelope but deer and wild boar merely living in some cape-heads or isolated islands. On the south-eastern part there is a mountainland of bear and antelope, named Sobo-katamuki Range. This is the unique territory in Kyushu District where the four animals are living together. Int the same regions there are other deer territories which have no wild boar—e. g. Hikosan mountains and Kunisaki Peninsula.
By more integrated research in Kunisaki Peninsula and Sobo-katamuki Range, the author has found that the selected attack of mankind to those mammals should not be neglected. For instance, the bears have been kept safely by the belief that who kills a bear must be haunted by its ghost even to postery, which has been kept till now at the foot of Sobo-Katamuki Range. On the other hand, since Meiji Era, the wild boar has been hunted more and more in many regions, because his meat began to have been tasted common since that time. Nevertheless this is a inferior condition than the ecological and topographical one, which has kept them from attack of mankind. For example, the author observes that the deer lives on steeper and savanna-like hillsides than the wild boar does, the latter of which preferes to gentle and dark bushed hills. And the latter runs slower than slower than the first, and always walks along the fixed tracks of his own, so then the native hunters skillfully follow and mark them when they hunt.
On the contry, the deer climbs steeper hillside very rapidly and rushes into shrub fields for every way when he is attacked. Thus the mountainous and virgin forests are the advantageous places for them—e. g. Fukaba (Kumamoto Pref.), Kurodake (Oita Pref.) and the Sobo-Katamuki Range kept a number of deer or wild boars, only bacause in such location their enemy could hardly act quickly enough to get them.

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On the 10 th of August, 1958, three months before the big eruption of Mt. Asama Volcano, the author surveyed the eastern slope of Asama Volcanic Cone in order to clarify the composing materials and the grain compositions.
The grain compositions are explained in this paper. The spots where the sampling station exploited are shown in Fig. 1. Samples were exploited every vertical 50 meters from the summit down to 1, 742m both on the ground surface and 50 cm under the ground.
Samples smaller than 2mm in diameter were sorted with sieves of the 1/2 scales that he had prepard experimentally.
The features of the grain compositions are shown in Fig. 3, Fig. 4 and Tab. 1. The conclusions are as follows:
1. On the 10 th of August, 1958, the surface strata on the eastern slopes of Asama Volcanic Cone were composed of andesite breccias and underlaid coarse grained pumices.
2. The Mdφ, Qdφ and Pdφ of each of them do not vary in height above the sea-level, but qreat differences are recognized between the samples on the ground-surface and 50cm under ground even at the same spots.
3. Fine grained materials smaller than 2mm which are mixed with andesite breccias on the groundsurface and coarse grained pumices 50cm under the ground are distinguished to be quite dif erent as the result of sieving.
4. Considering the differences of grain compositions shown in Fig. 3 between the groundsurface and 50cm under the ground in comparison with the fact that the strata near the ground-surface are separated into two layers, andesite breccias and coarse grained pumices, the author suggests that the varieties of the scales of volcanic activities of Mt. Asama resulted in the establishment of discontinuous surface 50cm under the ground.

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