352 E. E. Eoicorth—The Loess. 



Loess is not being stripped from Mongolia, but is growing tliere too, 

 as it is in China. How, again, can we understand a patch of steppe, 

 in the centre of a vast area of Loess, supplying all the country round 

 with dust, while it is being stripped itself by all the winds of heaven ? 

 for we must remember that the Eussians have shown that in the 

 province of Irkutsk, north of the Gobi Desert, Loess occurs as it 

 does in China. The problem of deriving the main body of the 

 American Loess from the small area known as the American Desert 

 would be equally great, even if it were proved that the ingredients 

 of the Loess were ready there for these winds to act upon. Again, 

 I must urge what seems to have escaped Baron Richthofen, that it 

 is quite clear from every consideration that the Loess belongs to the 

 same geological horizon as the diluvium of the French and Eussian 

 writers. The contents, animal and vegetable, and the primitive 

 works of man which it contains, as well as its stratigi-aphical 

 position, all prove this. Again, although the Loess differs from the 

 loams and brick-earths in its texture, and in the abundance of 

 carbonate which it contains, yet its mode of distribution, as we have 

 shown, is essentially the same, both being spread over high ground 

 and low, irrespective of the drainage, and being otherwise similarly 

 distributed. Any theory that accounts for the distribution of the Loess 

 must also therefore explain the idiosyncrasies of the loamy deposits. 

 Assuredly the wind theory of Baron Eichthofen would even by 

 himself be deemed incompetent to explain the difficulties of the 

 brick-earths and upland loams of Western Europe. Prof. Aughey 

 urges an objection which is closely connected with this. He says 

 very properly, that " a fact often overlooked is the transition character 

 of some beds of sand as they shade into the Loess. As beds of 

 Loess and stratified sands at the bottom of Loess sections often 

 alternate, and even sometimes with strata of clay, it is not easilj'- 

 conceivable how subaqueous agency should have formed the one, 

 and geolian agency the other" {op. cit. p. 280). Lastly, Baron 

 Eichthofen argues as if all the debris found in the Loess were sub- 

 aerial. This is not so, however. In America, in China, and in 

 Europe it is quite true that the land shells prevail largely over the 

 water shells; but the latter are certainly fotmd in appreciable 

 numbers, especially in the Loess of Iowa, showing that considerable 

 lakes or rivers must have existed, which is again proved by the 

 traces of stratification in certain areas. I think the American 

 geologists exaggerate the extent of these lakes from overlooking the 

 fact that the Loess has been largely transported and rearranged, 

 and thus its contents have been swept over a wide area remote from 

 their original site ; but it is nevertheless absolutely clear that 

 evidence of such lakes exists, and such lakes in fact exist still. 



In Clay, Fillmore, York, and other counties, says Professor 

 Aughey, "there ai-e considerable numbers of ponds, covering from 

 a few acres to half a section of land, grown up around the border 

 with reeds and coarse grasses and sedges, and, where the water is 

 deeper, with arrow leaves, pond-lilies, and other water plants. In 

 every instance where I had an opportunity to examine them, there 



