458 Catastrophism and Evolution. [ August, 
been for the most part permanent oceanic area ever since the sub- 
mergence of the archwan America, emerged and became the 
‘ new continent of America, which has lasted with local vicissi- 
tudes up to the present. The east and west were, indeed, sepa- 
rated by a mediterranean sea, the sole relic of the American 
ocean, which now occupied a narrow north and south depres- 
sion. : 
In that mediterranean sea, we may say that the conditions have 
been uniformitarian ; that is to say, in the great post-Palozoie 
catastrophe that ocean was spared. It remained a body of deep 
water, its bottom undisturbed by folds or dislocations, and there 
- is no evidence of a cessation of sediments ; yet the species which 
lived there throughout the vast length of the coal period were 
completely extinguished, and entirely new forms made their ap- 
pearance. Although spared from the actual physical catastrophe, 
the effect of the general disturbance of that whole quarter of the 
globe was thoroughly catastrophic, and exerted a fatal influence 
upon life far beyond the actual theatre of upheaval. 
Passing over the Mesozoic age, which in detail offers much in- 
structive material as to rate of change, we pause only to notice a 
catastrophe which marked the close of that division of time. 
In a quasi-uniformitarian way, 20,000 or 30,000 feet of sedi- 
ment had accumulated in the Pacific and 14,000 in the mediter- 
ranean sea, when these regions, which, during their reċeption of 
sediment, had been areas of subsidence, suddenly upheaved, the 
doming up of the middle of the continent quite obliterating the 
mediterranean sea and uniting the two land masses into one. 
The catastrophe which removed this sea resulted in the folding 
up of mounfain ranges 20,000 and 40,000 feet in height, thereby 
essentially changing the whole climate of the continent. Of the 
land life of the Mesozoic age we have abundant remains. Thanks 
to the paleontologists, the wonderful reptilian and avian fauna 
of the Mesozoic age is now familiar to us all. But after the ca- 
tastrophe and the change of climate which must necessarily have 
ensued, this fauna totally perished. The rate of this post-Creta- 
ceous change was, in other words, catastrophic. 
During the Tertiary, fresh-water lakes of wide extent occur 
pied the western half of the continent. Such was the character 
of the great post-Cretaceous uplift that there were left broad, 
deep continental basins above the level of the sea. Into these 
the early Tertiary rivers found their way, creating extended lakes — 
in which accumulated strata rivaling in importance the deposits 
