ON ENVIRONMENT 
bed of that sea before it began its long process of 
leakage or evaporation. 
In these regions, so far as is known, the North 
American cactus seems to have originated. 
Back in the ages before the evaporation of the 
inland sea was complete, the heat and the moisture 
and the chemical constituents of the sandy soil 
combined to give many plants an opportunity to 
thrive. Among these was the cactus, which was 
an entirely different plant in appearance from 
the cactus of today, no doubt, with well defined 
stalks and a multitude of leaves, each as broad as 
a man’s head. 
As the heat, which had lifted away the inland 
sea, began to parch its bottom, the cactus, with the 
same tendency that is shown by every other plant 
and every other living thing, began to adapt itself 
to the changing conditions. 
It gradually dropped its leaves in order to 
prevent.too rapid transpiration of the precious 
life-supporting moisture. It sent its roots deeper 
and deeper into the damp sub-stratum which the 
sun had not yet reached. It thickened its stalks 
into broad slabs. It lowered its main source of 
life and sustenance far beneath the surface of the 
ground and found it possible, thus, to persist and 
to prosper. 
Perhaps there were, in the making of the 
[15] 
