49 
woods of today fringed their shores. The climate of that age 
must have been radically different from ours of today, as a whole, 
because of the presence of the inland seas, which must have caused 
the humidity to be at saturation point most of the time, and there- 
fore, must have prevented the existence of arid plants. In addi- 
tion to that, it was a period of great volcanic disturbance and im- 
mense lava flows covering thousands of square miles, which must 
have increased the temperature of the region and also the amount 
of carbonic acid in the air. It was also an age of mountain mak- 
ing, where the structure of today as we see it, was formed in large 
part, and where every possible opportunity for the development of 
vegetable life occurred, from the frigid to the tropical. The seas 
formed ample means for the distribution of seeds from one moun- 
tain range to another, and thus facilitating a uniformity of the 
vegetation along their shores, while the freshness of the water 
prevented the destruction of the seeds. During this time there is no 
alkali plains and lakes. Utah and Nevada at that time were set 
of parallel ranges of mountains with broad valleys draining down 
to the Colorado and the Columbia. Soon after that, volcanic dis- 
turbances formed the Great Basin and cut off the drainage to the 
north and south. ; 
t — time the profound disturbances of the earth’s phate 
toward the north cut off the warm ocean currents from the North 
