216 The American Naturalist. [March, 
ning off through the creeks to the Missouri River. Occasion- 
ally one meets with a very ludicrous explanation; and not the 
least among the ludicrous is the idea of electrical disturbances 
produced by iron rails and barbed wire fences. When there 
were few fences, and the Union Pacific was about the only 
railroad in the state, the disturbances were said to be produced 
by the rails, later the barbed wire fences played the chief part 
in precipitating atmospheric moisture. In reply to such 
ignorance and credulity, which, by the way, makes it possible 
for the early lightning rod swindler or his kind to turn rain 
maker, about all that need be said is that judging from reports 
from the various prairie states during the present summer, a 
great many fences must have been taken down. 
Near Harrison and southward the surface of the country 
rises and falls in long, sometimes “rolling hills.” From an 
altitude of 4871 feet at Harrison it rises to considerably over 
5000 on the highest point of Pine Ridge northwest of the town 
and on the western edge of the state. Through this high 
table land deep cafions have been worn by the White and Ni- — 
obrara Rivers on the south, while on the north, the deep, broad 
valley of Hat Creek has been cut out by an insignificant tribu- 
tary of the south fork of the Cheyenne. Along the northern 
edge of this table land and along the edges of that forming 
the divide further eastward between the White and Niobrara 
Rivers, may be seen numerous clumps of the western or yel- 
low pine which have given the name to the ridge. Back into 
the ridge have cut numerous deep cafions the branches of 
Hat Creek. In these, cottonwoods, box elders, ash, elms, wil- 
lows, and other trees find enough moisture and protection to 
flourish. In their upper courses they sometimes break up into 
numerous deep and precipitous ravines, and at the extreme 
heads of these are found those eroded places that present the 
appearance of, and are known as “ blow outs.” In some cases 
their lack of connection with the ravines leaves no room for 
doubt that they can be anything else than wind-formed exca- 
vations. 
It is in these “blow outs” and ravines that the peculiar 
“ cork-screw ” fossil is found. In some cases they may be seen 
