248 Tg Als UHOVOTEIN, 
which the mass may be caused to split more or less readily. 
Occasionally layer after layer may be peeled off by the insertion 
of the blade of a knife inthe seams which separate them. In 
one instance the surfaces exposed in this way were smoothened, 
as it were, by a thin film of dark ferruginous material which 
evidently had been deposited by infiltration along the seams 
separating the layers. The flutings are straight, compound folds 
in the layers. When the latter are viewed in a section vertical 
to the trend of the flutings, they appear as parallel, very shallow 
waves an inch or two in width. On these there is a second par- 
allel system of small folds only about an eighth of an inch 
wide. These also have a very shallow depth, which barely ren- 
ders them perceptible. Occasionally the layers wedge out, the 
seams separating them running together. To one familiar with 
the appearance of ripples and ripple marks, a glance at the sur- 
face of these layers in the loess suffices to show that they have 
nothing in common with the former. The ridges of ripple 
marks are never straight. Their opposite slopes are regularly 
unsymmetrical, always steeper in one and the same direction for 
successive waves. There is no second series of smaller waves 
parallel with the larger ones. Ripples are also somewhat uni- 
form in size. They are invariably associated with sorting of 
coarse and fine materials. In vertical section the flowing curves 
of ripples constantly intersect. None of these characteristics 
appear here. The folds and flutings in the loess are straight, 
it might be said rigidly straight. The slopes of the folds are 
symmetrical, or irregularly unsymmetrical. There is also a con- 
siderable variation in size of the folds. As stated before, there 
is no sorting by which coarse materials have been separated 
from the fine. The partings between the layers tend to run 
parallel. When they do run together it is not with the flowing 
curves seen in the ripple marks. But an analysis of the differ- 
ence between the two phenomena really blurs the vividness of 
the intuitive distinction perceived by direct inspection. The 
character of the surface exposed when the laminz are laid bare 
along their partings is much more like that of slickensides or of 
