ON ENVIRONMENT 
cactus slab today we see evidences of adaptability 
more wonderful than this. 
“The slab of cactus is a brilliant green as we 
put it in the ground. It is flat, of an oval shape, 
an inch or less in thickness. Its internal structure 
is of soft, mushy fiber, mostly water. 
“As that slab sends down roots, it begins to 
prepare itself to bear the burden of the other slabs 
which are to grow above it. 
“The thin, flat shape thickens out until it is 
almost spherical; thus presenting a curved surface 
in four directions instead of in two, it braces itself 
against the winds which will play with the new 
slabs far above it. 
“Its mushy wood fibers grow tough and 
resistant; it loses much of its watery character. 
“It changes in color, from green to brown; it 
loses its velvety skin and develops a bark like 
that of a tree. 
“Within a year after planting, this cactus 
slab will have changed in appearance and in 
characteristics to fit itself to the new conditions 
which surround it. 
“It will have changed its structure to bear 
weight and stand strains. It will have modified its 
internal mechanism to transmit moisture instead 
of to store it. It will have remodeled its outer 
skin to protect itself from the ground animals from 
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