262 
THE GEOLOGIST. 
pipe would increase in magnitude more rapidly in the direction ol c d than of 
A c, B d, m other words, would deepen more rapidly than it widened. 
Further, as the dijnensions of the pipe increased, so would the disproportion 
between A a and A c, and between b B and B d, constantly increase ; and as 
only the same relative quantity of water would pass over the surfaces A c, B d, 
whatever their dimensions might be, its effect would be one gradually dimi- 
nishing, and consequently the lateral growth of the tube would tend to become 
less from day to day, whilst as the proportion oi c d with regard io a b would 
continue with little variation, whatever the size of the pipe." 
By this explanation we may to a certain extent understand the method in 
which these singularly long narrow pipes were produced. The pipes that we 
have been describing in many points seem to accord with the theory of chemical 
errosion ; in their extreme depth, the occurrence of flints indiscriminately 
throughout, by the nninterrupted passage through them of bands of flint- 
nodules, and in the disintegration of the chalk suiTOunding and forming the 
.sides of the pipes. 
The patches of clay shown in the diagram (fig. 1) would also prove the 
disintegrating power of the water on the sides, and that a certain portion of 
the water escaped in that direction ; the inclosed sandy clay, assisted by the 
oxide of iron, would, as it became dry, attach to itself the powdery chalk, and 
when, as was the case, masses of the chalk fell down, portions would remain 
adhering to the clay, while others would fall with the mass of chalk, causing 
the patclied appearance mentioned above. The erosive action was apparently 
so gradual that the flints were kept in their right position ; and so gently has 
the chalk in the interior of the pipe been removed, that the projecting portions 
of the flints have not been broken off. — EoMrxD Jones. 
Eexaiks of A:meeican " Missourium" associated with Tlint-Implements 
(" Tsotes and Queries," p. 217). — As it is very desirable that any matter con- 
nected with the assumed contemporary existence of man with the great extinct 
animals should be cleared up as far as practicable, I wish to append to the paper 
by Dr. Koch, which your correspondent, Mr. Bensted, obligingly transcribes, 
an abstract of an article by Dr. Wislizenus (Trans. Acad. Sciences, St. Lonis, 
vol. i., p. 168), in which, after noticing the discovery of the Mastodon giganteus, 
as an upright skeleton in clay, partly consumed by fire, and associated with 
stone weapons, he takes exception to the conclusion of Dr. Koch, that the 
animal, while thus mired, was kiQed by a human onslaught. 
After showing that the discovery of Mastodon skeletons in an upright position 
is far from an unusual event, he suggests the following combination of circum- 
stances, as a more natural and Likely way of solving the question : 
"An Indian family, attracted by the springs, selected centuries ago that place 
for a residence, and fixed their tent or wigwam on the very spot below which, 
unknown to them, the bones of the mastodon rested. The ground covering and 
hiding the bones formed then but a superficial layer, perhaps a foot in depth. 
The household fire made in the centre of the lodge, as is the Indian custom, 
and kept up for weeks or months, would be quite sufficient to form the hollow 
in the ground wherein a layer of ashes would be collected, the heat from which 
would be quite sufficient to burn, to some extent, the nnder-lying buried bones. 
The presence of stones in the ashes may also be accounted for by remembering 
that among primitive nations a common mode of cooking is that of burying 
meat in earth-ovens, dug a foot or more in depth and partially covered by a 
layer of stones, which would, when heated by the fire at the bottom, assist the 
cooking-process. Another Indian custom, that of placing stones upon the 
lower end of thin tents to keep them closer to the ground, may also be cited. If 
such an ancient lodge was left undisturbed alluvial deposit would accumulate 
