ALTERNATIVE HYPOTHESES 151 



stance unstratified (in the main) with pebbles that vary in size from 

 that of peas to 4 inches in diameter; but none of the fluvio-glacial ter- 

 races that are known to date from the Wisconsin stage, so far as they 

 exist along the Missouri or the Mississippi, are of such materials. They 

 are uniforml}^ fresh, clean, and nicely stratified. Any flood-plain deposits 

 formed later than the Wisconsin ice epoch would necessarily be equally 

 fresh, whereas these are rotted in siiusind could not have been brought 

 to their present places in the state of decay which they exhibit. They 

 would have been washed entirely clean, and could not now show the 

 layer of decay by which (when not wholly rotted) they are uniformly 

 inclosed. 



3. That the material in which the skeleton lay, and that which rises 

 to the surface forming a stratum about 20 feet in thickness, is the result 

 of debris from a higher bluflf which once existed at this point but has 

 become degraded by time, this bluff having consisted of Carboniferous 

 strata capped by drift and loess. It is possible to admit such origin for 

 the portions numbers 1 and 4, as already described, with the excep- 

 tion that they must have been formed prior to the deposit of all the 

 overlying loess and not at all contemporary with it. Their composition 

 is wholly different from the overlying loess and they must have been 

 formed without the presence of the loess. It is evident that they can be 

 referred to the Carboniferous shale and limestone and only to them. 

 They constituted a residual clay that antedates the loess and which was 

 a land surface for a long period before the deposition of the loess. This 

 requires that the contour of the Carboniferous was formed before the 

 epoch of the loess, and that no such bluff of Carboniferous rocks (since 

 obliterated) existed at the points supposed when the loess was placed 

 there. Again, granting such may have been the origin of the loess in 

 question, we meet with serious perplexities. First, such a crumbling, 

 accumulating talus slope would not arrange its debris in horizontal 

 la)^ers, but the rolling pebbles would be arranged in layers (if at all in 

 layers) parallel wit-h the slope of the bluff or of the talus. Second, such 

 descending debris once arranged, whether horizontal or oblique, if later 

 than the Wisconsin epoch, would be fresh and unrotted, for there has not 

 been time sufficient since that epoch to effect such decay. If it were 

 done prior to the Wisconsin epoch, it must have been in either the 

 Buchanan or Aftonian interglacial epoch, which would be rather old, 

 but at such epochs the Missouri river flowed, as shown by soundings to 

 the rock bed at Council Bluffs and elsewhere, probably 75 feet below its 

 present surface. 



4. That the skeleton may be pre-Kansan, which would require still 

 greater antiquity. In reply to this supposition, it may be pointed out 



