JOURNAL OF THE COLLEGE OF SCIENCE, TOKYO IMPERIAL UNIVERSITT. 



VOL. XXXII., ARTICLE 5. 



Climatic Changes in Japan since the Pliocene Epoch. 



By 

 Malajiro Yokoyama, B'Kjakuhakuski. 



Professor of Pahrontolony, Imjjci'ial Univertiit)j of Tohjo. 



With 1 Plate. 



As is well known, one of the striking features of the climate 

 of the primEeval world was the occasional interruption of a com- 

 paratively warm and uniform climate by one of intense cold. The 

 time during whicli such a cold climate prevailed is called an ice-age, 

 because of the enormous quantities of ice which in the form of 

 glaciers covered the land, smoothing, polishing and scratching the 

 rocks over which they moved, and carrying with them erratics and 

 moraines, just as they do to-day in the Alps and in Arctic 

 countries. Geologists have ascertained that such ice-ages have 

 visited the earth at least tliree times during the past. The first 

 visit was during the Eozoic or Precambrian, the period in which 

 the first dawn of life appeared in the world. Evidences of this age 

 have been discovered in China, Canada and Northern Norway. 

 The second was toward the close of the Palœozoic era, in a period 

 called Permian. This time the ice chiefly invaded the countries 

 around the Indian Ocean — India, Australia and Southern Africa. 

 The so-called Glussopteris flora, which resembles that of the succeed- 

 ing Mesozoic more than that of the Palaeozoic and which flourish- 

 ed during the Permian period in the above named countries, is 

 often brought into connection with this second glaciation, on the 

 assumption that it was the result of the transforming power of the 

 cold acting on j^lants of the Palaeozoic which remained unchanged 

 until its close in places where there was no glaciation. 



