346 H. S. EoicoHh—The Loess. 



quadrupeds of the Loess, and witli tliem occur other forest animals. 

 If "we turn from the mammals to the molluscs in the Loess, the very 

 large proportion of which are land shells, the same conclusion is 

 inevitable. Those concbologists who are best able to decide such a 

 question agree that the Helices and other shells of the Loess lived 

 in the recesses of damp woods, and their abundance proves the con- 

 ditions to have been singularly favourable to them, namely, those 

 of a humid atmosphere and of deep shade. 



I have quoted European authorities for this view whose experience 

 is overwhelming. Let me add to them that of my correspondent, 

 Prof. Todd. Speaking of the abundance of land and the paucity of 

 aquatic shells in the American Loess, he says : " However, some 

 semi-aquatic species, as Saccineas and Helicinas, are very abundant 

 from top to bottom of the formation, and the decidedly aquatic 

 Limnea humilis is quite abundant in the Upper Loess of Western 

 Iowa. This is sufficient to show that the formation, so far as this 

 region is concerned, could not have been so dry as is called for by 

 Eiclithofen's theory. Even the land shells observed need a much 

 moister region than our upland prairies in their present conditions. 

 Some of them are not found at all, away from moist banks or groves." 

 Again, " I think no one can study the life of the Missouri Loess with- 

 out seeing that it bears, throughout, evidence of a moist climate, the 

 very opposite of the Baron's ideal." — (liichthofen's Theoiy of the 

 Loess, by J. E. Todd, p. 6.) 



The evidence of the mammals and shells is supported also by the 

 debris of vegetation in the tufas, which prove the former existence 

 there of luxuriant forests. All this is entirely at issue with the 

 Baron's postulate, and in fact cuts the ground from beneath it. I 

 referred to it in my paper, but he does not notice it in his reply. 



The existence of thick moist woods is assuredly inconsistent with 

 the dry winds and dry grass pastures which he requires for histheorj'', 

 inconsistent also with the prevalence on any scale of those dust- 

 storms which he postulates, and perhaps the best proof of this is that 

 while the Loess is such an exceedingly fertile soil, in North China, 

 where local dust-storms prevail largely, nothing is more remarkable 

 than the virtual absence of trees over many degrees of latitude — a 

 circumstance which the Pere David has made much comment upon. 

 We have not yet done with the fossil contents of the Loess. In 

 certain places, as we have urged over and over again, the remains 

 of the animals are found intact, showing that they could not have 

 been transported very far. In other cases they are found buried in 

 hecatombs. In others again, and most frequently, the bones are 

 found sporadically and much scattered. In all cases, as we have 

 tried at very considerable length to show, they present evidence 

 of having been largely disturbed and transported. How could such 

 agencies as the Baron invokes explain the presence of great heca- 

 tombs of animals buried pell-mell together, or the presence in some 

 cases of whole skeletons of Mammoths and Ehinoceros, or explain 

 in others the dispersal of their bones. All these factors are incon- 

 sistent with continuous gentle atmospheric agencies only and with 



