Lansing Pleistocene. Geology. — ]]'inchell. 277 
writer's sample No. i was obtained in the floor of the offset 
tunnel, a little eastw^ard from the place of the skeleton. 
11. The peculiar character of the water-laid stratum of 
silt, and its calcareous ingredient have been discussed under 
No. 7. Its marked resemblance to the layer on which it lies, 
and their remarkable differences, in structure and composition, 
from the loess that overlies the silt stratum, set them off from 
the rest of the materials pierced by the tunnel, and require for 
them an earlier date and a different mode of accumulation. 
(See Appendix.) 
12. How can a limestone become "softened," in the or- 
dinary use of that word, unless it become rotted? Limestone 
does not soften either by atmospheric exposure or by mois- 
ture, unless it is chemically so changed that it has lost its car- 
bonic acid and has acquired water. Such an alteration can 
hardly be expected in materials deposited by the waters 
of the Wisconsin glaciation, much less by operations of flood- 
drainage within more modern time. These "softened" lime- 
stone fragments could not have been introduced into this de- 
posit in their present condition, but they must have rotted 
in sitn. 
13. The description of the main material cut bv tlie side 
tunnel of Air. Fowke is nearly as the writer would make it — 
he, only would add that the arrangement of the coarse mater- 
ial, whether of limestone or of '"other debris" is sometimes 
in indistinct horizontal bands or belts, and that the other de- 
bris is in part of drift pebbles which are also in the main rocted 
in sitn, indicating a longer age than since Wisconsin time. 
Rounded quartz pebbles about half an inch in diameter were 
taken by the writer from some of these belts of coarser debris, 
all the other pebbles having become so' "softened" that their 
positions were shown by white spots, when of limestone, or 
loose rusty spots when of "other debris." The "gravelly as- 
pect," moreover, so far as observed by the writer, was con- 
fined to such horizontal belts, although the rotted stones were 
seen scattered more or less throughout the mass. The loess- 
kindchen are notably most abundant in the horizontal gravelly 
belts. 
Whether this should be called "a typical loess deposit" de- 
pends on what and where the type deposit is found and when 
