THE CHASMS OF THE COLORADO. 359 






























That these characteristics of the fauna mentioned are, in 
comparison with others, really successional, in the same 
manner as are different geologic epochs in relation to each 
other, can be proven by the study of the anatomy and devel- 
opment of the species of each. Their relative greater or less 
extension during the periods of geologic time also furnishes 
an indication of a chronic relation now existing between 
these faunæ. Thus we have before us some of the terms 
of that grand proposition, whose demonstration must ever be 
of high interest to mankind. 

THE CHASMS OF THE COLORADO. 
BY A. HYATT. 

In Niagara we readily realize the power of demolition 
attributed to its waters. The Fall is still receding, the 
ground is shaken under us by its blows, the chasm it has cut 
yawns before our eyes. But it is another and far different 
matter to recognize the same force in other localities, where, 
perhaps, a puny stream, depleted by the summer heats, trails 
along the centre of some deep gorge. 
Here the observer must remember that time has no boun- 
daries in geology; that existing causes, provided they are 
“pable of carrying away ever so small a portion of solid 
it and rock now, would, in ages past, have had oppor- 
ity enough to have destroyed the whole of the rocky core 
Which once filled the ravine. 
si him descend and look at the tottering pinnacles threat- 
ra him from above, and then examine those that have 
L in. The layers of the shattered masses are open 
Power ice-wedges in winter, the grinding and transporting 
cold of the spring freshets, the alternate heat of noon an 
of night. Acted upon also by the oxygen of the air, 

