DECEMBER 31, 1897.] 
glacial gravel terraces to higher levels, 
though it rarely takes the forms of distinct 
dunes. It is frequently three to five feet 
in depth, facing the bluffs above the glacial 
plain in irregular patches, or capping their 
crests. 
The trenches in which the human relics 
near Trenton have recently been found 
are upon the immediate edge of the plain 
overlooking the post-glacial valley of the 
Delaware. Here, as is frequently the case 
in such situations, thé sandy loam over the 
gravel of glacial age is thicker than farther 
back from the bluff, but even here it is 
but three or four feet in thickness, includ- 
ing the black soil. It isin this sand and 
loam, quite above the materials which are 
clearly of glacial age, that the human relics 
are found. 
In detail the sections shown in the 
trenches open in May and July showed a 
sandy soil affected by organic matter to the 
depth of six to twelve inches, the lower 
limit being. ill-defined. The soil graded 
down into sand which was essentially free 
from organic matter, and which had a 
thickness of two to three feet. The sand 
was without apparent stratification. Below 
it lay the stratified drift, confidently re- 
ferred to the time of the last ice epoch. It 
will be seen, therefore, that the relics were 
found in the structureless sand and loam 
which overlay the sand and gravel of 
glacial age. 
Besides being essentially structureless, 
the sand and loam in which the relics were 
found contained occasional pebbles. Some 
of them were as large as one’s fist, and oc- 
easionally one was found of still greater 
size, though most of them were tiny peb- 
bles. Many of them were so small as to be 
within the power of wind to transport, 
while others were so large as to make this 
mode of transportation impossible. 
In the sand there were at some points 
streaks more highly colored than the por- 
SCIENCE. 
979 
tions above or below. These streaks had a 
position approaching horizontality, but in 
detail they were exceedingly irregular. 
Locally they were interrupted, apparently 
broken ; and in other places they faded out 
altogether. In general they were thin, a 
trifling fraction of an inch in thickness. 
They were sometimes so faint as to be 
traceable with difficulty, while in other 
places they thickened to a quarter of an 
inch or more. While these streaks were 
often distinct, they were not to be mistaken 
for lines of stratification, with which they 
clearly had nothing to do. They could not 
be assumed to be the edges of stratification 
plains distorted by unequal sinking, for if 
this were their origin successive streaks in 
the same vertical section should have cor- 
responded in their irregularities. This was 
not the fact, for one streak was liable to 
bend up just where the one a few inches 
below it bent down, a relation which ex- 
cluded the idea of unequal settling. Fur- 
thermore, they were so irregular that their 
total length, as seen in the face of a trench, 
measuring all irregularities, was consider- 
ably greater than the length of the section 
itself. 
These reddish streaks, which were thought 
to carry more pebbles than the other por- 
tions of the sand, seemed to be due to one 
or more of two or three causes. In places 
they seemed to be due to the concentration 
of coloring matter, especially iron oxide. 
In other places they looked rather as if fine 
reddish silt had accumulated along them 
through the influence of percolating water. 
In either case there must have been some- 
thing in the texture along this irregular sur- 
face to occasion the concentration. The 
surface of which these irregular lines were 
the outcrops may perhaps once have been 
the upper surface of the land, subsequently 
buried by wind-blown dustand sand. Many 
of the little irregularities of the streaks were 
such as might be thus explained, though 
