In support of this view is the assertion that the bones were water-worn. On this point I can not venture any opinion, as I have not seen them. But I have found bones in mounds and in other situations where such wear was impossible and yet having the smoothed and rounded appearance characteristic of such action by water or the elements.
In support of this theory, too, is the positive statement of Nebraska geologists who have had ample opportunity to become familiar with loess in all its phases; and they claim the deposit is the original and has not been disturbed.
It is necessary for these advocates, however, to tell where such fragments of bones could have come from and how they could have been washed to the place where found, when all these bluffs were covered with water, as they had to be at that time.
2. The bones could have been carried by rodents into their burrows or runways, as Hrdli[vc]ka suggests. In this case the material in contact with the bones would have to be somewhat different in appearance and consistency from that which lay a few inches, or perhaps only an inch, away. The Nebraska men say this was not the case.
3. There may have been an excavation or pit similar to that in which the Hurons buried their dead. But as no such burial pits have been discovered in this part of the country, this supposition must be excluded.
A corollary to the last is that a deep but small pit similar to the so-called "caches" in the lodge sites may have been dug here and the bones thrown in. There is no indication whatever of a lodge site or any other form of habitation at this point, but I have found such pits in the vicinity of Indian houses, though not just on their site. The deepest one I have ever found was 10½ feet and less than 6 feet in diameter. There would be no difficulty in digging into this loose material as far as an excavator cared to go, until he had reached a depth at which he could no longer get the loosened earth to the surface of the ground. As mentioned above, a pit south of Omaha had a depth of 13 feet, or only 1 foot less than is claimed for this—or rather for the greatest depth at which it is claimed fragments of bone were found.
The objection made to this theory is that the earth thrown out of the hole was unmixed, presenting throughout the appearance and consistency of loess as it occurs where exposed in ravines or on slopes in the vicinity. It is contended that if any previous excavation had been made here and filled up afterwards the mixed earth would be easily distinguished from that which was not removed, and that the line of demarcation would be easily discernible.
As a rule, this is true; but when dry loose earth of homogeneous consistency is thrown out of a pit and then thrown in again without becoming mixed with any other it is sometimes impossible to distinguish it at a later excavation. This is especially true of earth free from vegetable matter, as ordinary sand; or composed largely of vegetable mold, as the soil in overflow lands which have built up mainly from floods carrying uniform soil sediment. The line of demarcation between the dug and the undug earth in such conditions may become indistinguishable except when a vertical face is made which shall show a clear section of both in contact.
It is now too late to learn anything about the matter from the site itself. So many persons have been digging that it would be impossible to know when the limit is reached between the original excavation—assuming it to have been made—when the bodies were interred, and that resulting from the modern researches. The question of age hinges upon the appearance of the earth in which the bones were found; and the only way in which we can now learn anything about it is to trench across the hill at some of the other burial places, in the hope of finding bones at a similar level, and determining from the conditions in which these are found how they came there.
It is beyond question that any soil, humus, or other discolored matter thrown into an excavation with ordinary soil or subsoil will be apparent for an indefinite time afterwards. But on some of these high points and ridges there is even now not a trace of soil. Frost and wind have worn bare spots where nothing grows or has grown for a long time. As this region was a prairie devoid of even brush when the whites settled here, it is evident that such slight protection as grass or weeds afford would not be sufficient to hold the earth in place in winter, and when the ground is once swept bare such humble forms of growth may not get a foothold in future. Anyone who has studied surface geology knows these facts.