12 Art. 5. — Matajiro Yokoyama : 



géosynclinal, as the geologists call it, whose formation is said to go 

 back at least as far as the Mesozoic. Then the American and the 

 Asiatic coast-regions, Japan, Formosa, the Philippines and even 

 the greater part of the Eyukyu Islands were already in a form 

 very nearly as we see them to-day. And if any one expects to 

 find out any great change in the form of the land, it would be just 

 at the head of the Tokyo Ba}^. This place is coloured in our 

 geological maps as Diluvial which, if marine, would transform the 

 Söbö Peninsula at that time into an island. But what is here 

 called Diluvial is a thick layer of subaerial loam evidently derived 

 from a volcanic ash which had fallen on the preexisting land made 

 up of Pliocene strata. From this we know that, in the Diluvial 

 Epoch, the topography of the region surrounding the Tokyo Bay 

 was not much different from wdiat we see at present. 



It is a well known fact that ocean-currents exercise a great 

 modifying influence on the climate of a country near which they 

 flow. And as the Kuroshio'^ flows just south of the Söbö Penin- 

 sula, one might think that by a little change of its course, it might 

 come to wash the shores of the Peninsula, thus raising the tempera- 

 ture of the water to a degree sufficient to fit it for the growth of the 

 reef-corals. But such a change in the course of the current can 

 never have been brought about without a marked change in the 

 configuration of the surrounding countries. Those who look only 

 on maps and are not well acquainted with actual meteorological 

 conditions are easily misled by the proximity of the Kuroshio 

 and over-estimate its warming power on our country. One must 

 always bear in mind that in winter in Japan a cold wind sets in 

 from the Asiatic continent either as a north wind or a north-west 

 wind, which not only cools down the land to a temperature quite 

 low in comparison with its latitude, but also prevents the warm air 

 floating ov^er the Kuroshio from ever approaching it and even 

 causes the current itself to deviate a little to the south. Therefore 

 the warming power of this current at this season is reduced to a 



1) Kuroshio means black current or black salt-w.iter, and not black salt as often trans- 

 lati'd in European books. This mistake is undoubtedly due to our shio |g salt and shio JU salt- 

 water being phonetically the same, though different in written characters. Another name for 

 Kuroshio is Ivurosegiwa which signifies dark rapid rinr. 



