Seismic data concerning to the crustal structure both in continental and oceanic region have so accumulated up to now that they ought to be put in order and systematically studied by earth scientists to serve as a reasonable foundation of their speculative part of researches for the unknown depths of the crust. In this paper, crustal structures derived from seismic researches performed in various parts. of the world in recent years by many authorities are presented in columnar sections, original or compiled by the writer. From these data it is noticed that the main crustal layers (seismic velocity layers) show gradual variation in their developments, according to major physiographical divisions of the earth, viz, mid-continental, marginal, off-continental, and oceanic areas. After discussing on the geological and petrological identification of seismic crustal layers and summarizing the general features of them, some tentative interpretations, based on the current theories in tectonics, geophysics, and other earth sciences, as well as these seismic studies, for the major variation of crustal layers and structures are presented, with some speculations on the derivation of the fundamental crustal structure that is common to the continental and oceanic regions. In conclusion, it may be stated that the variation of the relatively upper crustal layers is attributable mainly to the magnitude and age (young or old) of the tectonic cycles during which they were formed. For the major variation of lower crustal layers that are common to continental and oceanic regions, the writer has the supposition that it has resulted ultimately from the original variation of the material from which they were derived in the major earth provinces before-mentioned. Lastly, some remarks on the origin of magmas are added in connection with the present studies on the crustal structure.
Professor Hartshorne's 'The Nature of Geography ' has been widely read among Japanese professional geographers, since Professor I. Matsui had reviewed and then Dr. S. Nomura had translated it into Japanese. Its contribution was too much to write here, but he felt it necessary to supply deeper considerations. The writer generally agrees with the “Perspective” view and would like to express his concept here. Geography is a highly synthesized science, and its study is based on the active regions which have been formed through times and with intimately related human and physical phenomena. But complete synthesis is almost impossible. It should be strived for, with analyzing, comparing actual regions assisted by topical studies. But there remains several questions, for instance valuation of Fr. Ratzel's work with relation to prerent ecological study. And how we could get a proper seat of geography, as chorological science, among traditionaly divied natural and human or social sciences ?