Kusatsu-Shirane (7,498 feet) and san (7,731 feet) are well known in this chain.
The plain of Kwanto, the largest in the country, stretches between the Kwanto group and the Pacific Ocean. On the south it ex tends as far as the two hilly peninsulas, Boso (Awa-Kadzusa) and Miura, which enclose the Bay of Tokio, an outshoot of the Pacific. The plain is gently undulating, partly of Tertiary formation, but mostly covered by later de posits. It is drained by many streams, of which i Tone is most noted. Lakes and lagoons are numerous, and Kasumi-ga-ura near the mouth of the Tone is the second greatest lake of Japan. The plain is well cultivated and thickly populated. There are over 40 cities and towns with populations of over 10,000. Tokio, the capital of Japan, with its population of over 2,030,000, is situated on the mouth of the Sumida River, which flows into the Bay of Tokio. At a distance of only 19 miles from the capital is Yokohama, the greatest seaport in the country, and a little south is Yokosuka, one of Japan's naval ports. Many towns in the northern part of the plain are noted for their flourishing silk industry.
In the central part of Honshu, where the two great mountain systems meet, lies a zone of great tectonic depression, which is repre sented by the valley of Chikuma-gawa on the east, and those of Fuji-kawa and Kamanashi gawa and the lowlands of Matsumoto-daira on the west. Along this zone runs the volcanic chain of Fuji and many cones stand as the boundary posts separating the two topographi cal districts, Northern and Southern Japan. The chain originates in the far south in the Marianna Group in the Pacific Ocean; and running north • through the Volcano Group (Iwo-jima) and Shichito Group, it reaches the peninsula of Idzu on the south coast of Honshu. Several eruptions on these volcanic islands and of the submarine volcanoes have been recorded in recent years. Noteworthy among these is Oshima or Vries Island, which is now ac tive. The Idzu Peninsula with Amagi-san (4,546 feet) is linked with Honshu by the Hakone, which is well known for its large and beautiful atrio-lake. Ashi-no-ko, as well
as many hot springs. Next to Hakone and over Ashitaka stands the prominent cone of Mount Fuji, whose snowclad peak reaches the height of 12,392 feet. The chain tends toward northwest and north and passing through Kaya-ga-take (4,067 feet), Yatsu-ga-take (9,637 feet), Tateshina-yama (8,298 feet), it termi nates at the Myoko Group (Myoko-zan, 8,049 feet) on the coast of the Sea of Japan.
The southern arc of Honshu was first de scribed as a part of the Sinian System by Pampelly and then as a part of the Kuenlun System by Loczy, both considering it as a single system and an extension of Nan-ling or of Peling (Tsin-ling) on the Asiatic continent respectively. But Baron von Richthof en in a recent opinion says that it consists of two dif ferent mountain systems, which unite in south ern Japan; one chain on he coast of the Sea of Japan, which he names Chugoku Mountain being probably an extension of the Kuenlun System or Tsin-ling, while the other, which runs along • the Pacific Coast and is called the Kuma-kii Range, belongs to the mountain sys tem of southern China or Nanling. Without going into further discussions of these tectonic problems, we will turn our attention to the general topography of southern Japan.
Between the tectonic valleys of Fuji-kawa and Tenryu-gawa lies the Akaishi Mountain, which from its outline is often called Akaishi Sphenoid. It is composed of several ranges of various geological formations. The highest peak of the Akaishi proper reaches the alti tude of 10,145 feet, while the culminating peak of the whole group with a height of 10,332 feet is in the Shiramine Range, which runs parallel to the Akaishi proper on the eastern side of the Oigawa Valley. The northern ex tension of the Shiramine Joins a granitic mass with the precipitous peaks of Koma-ga-take (9,843 feet) and Ho-o-zan (9,551 feet). The southern extension of the Akaishi Range forms the mountain districts of Totomi and Mikawa, and disappears in the Akumi Peninsula.