marks, and there has never been another > large enough to efface 
or even modify these marks. Therefore the loess covering of 
these terrace bottoms must have some other than an aquatic 
In the flat table lands of the Wabash country, where the rain- 
falls have lain on the ground till removed by evaporation, the 
surface clay has an ashen color. On the high ridges, and at the 
crests of hills or ravines in the flat wet lands before mentioned, 
the surface clay is yellow, or buff colored. In the terrace river 
and creek bottoms the color is generally ashen, and the material 
a sandy loam, with occasional spots of pure yellow clay. 
If this loess is decomposed vegetable and animal matter, why 
does it assume so many shades of color, and varied coarseness or 
fineness of shades of sand grain, being buff colored on the high 
land, ashen on the flat and the terrace bottoms, black in the 
Illinois prairies, and Indiana swamps ? I do not pretend to 
answer, " Sufficient unto the day is the evil thereof" Nor do I 
know why the first fifteen outside growths of a white oak (and 
varying numbers for other trees) are white and will decay in a 
short time after the tree is killed, and all the inner growths are 
red and will ensure the weather many years after the white 
growths are gone ; but it is a fact. Fifteen years from to-day, all 
the present white growths will be red and far more durable, and 
new white growths will have formed outside of them. . 
My obsen^ations have been confined to my own locality, and 
my deductions may be very wrong. I submit them for whatever 
they may be worth. 
