The ice age in North America and its bearing upon the antiquity of man5th edwith many new maps and illus., enland rewritten to incorporate the facts that bring it up to date, with chapters on Lake Agassiz and the Probable cause of glaciation . roughout its mass, rendersit almost certain that any inclosed fossils would have beenrapidly dissolved. As to why this oxidizing and dissolvingprocess should have selected fossils of aqueous origin, andmade an exception in favor of those of terrestrial animals, I THE LOESS. 411 Professor Hilgard explains that the terrestrial fossils are, asa matter of fa
The ice age in North America and its bearing upon the antiquity of man5th edwith many new maps and illus., enland rewritten to incorporate the facts that bring it up to date, with chapters on Lake Agassiz and the Probable cause of glaciation . roughout its mass, rendersit almost certain that any inclosed fossils would have beenrapidly dissolved. As to why this oxidizing and dissolvingprocess should have selected fossils of aqueous origin, andmade an exception in favor of those of terrestrial animals, I THE LOESS. 411 Professor Hilgard explains that the terrestrial fossils are, asa matter of fact, found near tlie niaro-inal portion of the loess,where the destructive processes are least. Whether, also,there may not be a dinference between the destructibility ofland- and fresh-water shells is also a question. The occur-rence of nodules of lime throughout the mass points to sucha work of solution and redistribution bj water. In regard tothe frequent occurrence of the bones of the larger land-ani-mals, Professor Hilgard remarks: That the phosphaticbones should not have dissolved as easily as the mere carbon-ate shells is readily intelligible ; and as regards their mode ofoccurrence in the loess of the loAver Mississippi they are. Fig. 119.—Stratification of the loess in a railway cut at Plattsmoiith. Nebraska, at a dcplliof eighty-four feet from the surface. (From photograph furnished by Dr. A. \ of Kansas City. Mo.) (Chamberlin.) (United States Geological Survey.) always very much scattered, many bones belonging to thesame individual being rarely found together, but seeming tohave drifted widely apart. It is not easy to see how thecumbrous bones of the mammoth could have been widelyseparated in a subaerial * * American Journal of Science, vol. cxviii, 1879, p. 110. 412 THE ICE AQE IN NORTH AMERICA. It is to President C^hamberlin, again,* that we are in-debted for the most careful study of this problem in the Mis-sissippi Valley. According to him, the
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