Trans. NN. Y. Ac. Sct. 94 April 14, 
many other facts into one theory in which each bears a definite and 
important relation. In its entirety I claim it as new, and as differing 
widely from all that have preceded it. 
DISCUSSION. 
The PRESIDENT stated that he had been led to think that not quite 
so much uniformity of climate had prevailed in former periods as 
is often supposed. A very warm temperature had existed at the 
north in Tertiary times. However, there had been also great vari- 
ation in lower latitudes, ranging from tropical heat to a very cold 
climate when the ice overspread the land. But no evidence had 
been shown that these temperatures were synchronous. A remarka- 
ble fossil fauna of tropical character had been discovered by BON- 
PLAND in Bogota; but we were not in possession of facts permitting 
us to assert that these ammonite deposits of South America were 
laid down at the same time as those in the North. There was, on the 
other hand, considerable evidence of the occurrence of alternations of 
climate. High tides of temperature had existed certainly in different 
parts, of the globe, but there was no evidence that these had occurred 
at the same time. Thus the discovery of bodies of floodwood, left by 
earthquake waves at high points on different coasts, would be no evi- 
dence that these were deposited by the same flood over the whole 
globe. 
In Paleozoic time, comparatively moderate irregularities in temper- 
ature had prevailed, the sea being more uniformly distributed over 
the surface. During the Carboniferous period, the temperature was 
moist and equable, producing a luxuriant vegetation, but favorable 
also to the preservation of vegetable deposits. At the present day, 
peat accumulates in the greatest quantity wherever the climate is 
cool, moist, and equable—therefore, not in the tropics, where the wood 
is burned up under present conditions, and where it was not accumu- 
lated during the Coal-period. 
The plants of the Cretaceous were similar to those of the present 
day ; many genera in fact were identical with those now growing, 
e.g., the sassafras, magnolias, liriodendrons, etc. There was no evi- 
dence of a tropical vegetation in the early Cretaceous. Later, how- 
ever, palms and other tropical forms began to appear. The climate 
was in general of a temperate character. ~ 
The Tertiary deposits were characterized by a luxuriant though not 
tropical vegetation, such as is found in warm climates at the present 
day. Thus the deciduous cypress now reaches as far north as our 
Central Park in this city, but its natural habitat is further south. In 
