CAUSES OF CLIMATIC CHANGES 91 



the Atlantic, and thus the great loss of importance in the extension 

 of the Gulf Stream into the North Frigid zone. Third, a change 

 in the location of the wind and rain belts, their boundaries being 

 shifted twenty degrees southward, in the meridian of Iceland, the 

 same amount northward on the opposite meridian which passes 

 somewhat east of New Zealand, and remaining essentially un- 

 changed at the halfway points, which are located near the meridians 

 of Ceylon and the Galapagos." 



Such rearrangement of wind and rain belts "would tend not only 

 to glaciate northwestern Europe and northeastern America, but 

 would also place arid trade-wind climates cwi the northern side of 

 the belt now occupied by the equatorial rains of Africa and South 

 America, and at the same time place the equatorial rains on the 

 northern margin of the arid land areas now fovmd in the southern 

 parts of these continents. On the adoption of the present location 

 of the poles, the change would be reversed." The northern side of 

 the equatorial rain belt in Africa and South America should then 

 be found to possess topographic records of a wet climate recently 

 succeeding a dry climate, and the features of the region south of 

 the same belt should indicate a dry climate following a wet climate. 



Professor Simroth, of Leipzig, in his book. Die Pendulations 

 Theorie, ipo/ (86) has tried to explain some peculiar distributions 

 of organisms in the present period by oscillations of the poles along 

 the meridian of 10° E. latitude (170° W. lat.). With an oscilla- 

 tion of 20° back and forth this would bring the north pole at one 

 time near Behring Strait, and at the other extreme in the Arctic 

 Ocean, west of the northern end of Norway. If the former posi- 

 tion was held in Pliocenic times, the Pacific side would be cool and 

 gradually become warmer, with the change of the pole to the oppo- 

 site position ; while on the Atlantic side the change would be from 

 warmer to cooler conditions terminated by glacial climates. Such 

 conditions seem actually to have occurred, as shown by the gradual 

 change from a warmer climate than at present at the beginning of 

 Pliocenic time in Europe, to the glacial conditions in Pleistocenic 

 time, and by a gradual increase in warmth on the Pacific side as 

 shown by the Pliocenic deposits of Japan, until in the Pleisto- 

 cenic the sun shone in the region of Noma (35" N. lat.), "with 

 about the same intensity as it now shines at least on the Ryukyus 

 or the Bonin Islands." (Lat. 2y° N.) This explanation has 

 found its most recent advocate in the brilliant paleontologist of the 

 Imperial University of Tokyo, Professor Matajiro Yokoyama (Yo- 

 koyama-iio://(5). Investigating this pioblem, G. H. Darwin (22) 

 came to the conclusion that, if the earth is quite rigid, the pole may 



