E. R. Eoivorth—The Loess. 351 



■whence the dust could come, and there is abundant evidence that 

 the dry steppe-climate of Baron Richthofen is virtually out of the 

 regions of possibility. But he makes still greater demands on our 

 faith when, not content with speaking of a steppe climate, he speaks 

 of such steppes as if they were the equivalents of or had any 

 analogy with the Siberian tundras, and treats the two as if they 

 were the same thing. The tundras are as different to steppes as 

 anything can be ; they are covered with thick moss, and can neither 

 be denuded by winds nor have their substance increased by them. 

 They are essentially exceedingly humid, and quite different to the 

 dry areas he otherwise speaks of. Sui-ely we require some explana- 

 tions of these extraordinary statements. Here let me say paren- 

 thetically, that Baron Richthofen cannot be serious in urging that 

 the proof of the identity of the Pleistocene fauna of Europe, in- 

 cluding that of the Loess, with that buried under the tundras, was 

 reserved for Dr. Nehring. Has he forgotten the name of Cuvier, 

 to select only a very big name from a large crowd, who proved this 

 elementary position long before Dr. Nehring was born ? Nor as- 

 suredly can he be serious in supposing that when the Fig, the Cyrena 

 fluminalis, and the Hippopotamus lived in Europe, the climate here 

 was like that now current on the lower Obi and Yenissei. If he 

 really urge this, in view of all the facts and the matured opinions of 

 the Russian naturalists which I have brought together in the earlier 

 papers of this series, then I have nothing more to say. 



Baron Richthofen postulates two climatic conditions as having 

 succeeded one another in regions where Loess prevails, one marked 

 by extreme dryness, the other by great damp. How is this shown, 

 when both the fauna and flora point to a damp climate having 

 existed at the time when Baron Richthofen demands a very dry one ? 

 But apart from this, we are reasonable in asking for some foundation 

 upon which to rest such meteorological revolutions in such areas as 

 China, the valley of the Mississippi, and Central Europe. It is 

 easy to postulate a humid climate following a continental one, in 

 which the conditions were almost the reverse of each other, so long 

 as we limit ourselves to possibilities of thought ; but we, who are 

 morbidly anxious for some reasonable explanation of our difficulties, 

 must have something more than transcendental predicates. We 

 must have inductive ones. I know that local dust storms in North 

 China do prevail, as they prevail in Mongolia and in North America, 

 where the Loess exists ; but, as Professor Call says, the evidences 

 of such action are purely local, and dust storms merely tend to 

 rearrange the surface, denuding the windward, and covering more 

 deeply the leeward, bases and sides of the hills ; but these winds 

 do not help us to explain either the origin of the Loess or its 

 general distribution. 



There is no evidence that the dust from the Mongolian steppes is 

 now adding to the Loess which occurs in China, which is separated 

 from Mongolia by the well-known chain of mountains that runs 

 north of the Yellow River. But suppose it were, we should be no 

 nearer solving our problem ; for Baron Richthofen urges that the 



