304 
THE PLANT WORLD. 
little starveling shrub is kept sheared of its tender twigs through¬ 
out the summer. The only way in which the shrub can outwit its 
enemy is to continue to put out side shoots from year to year, 
letting the cows nip the young and tender tips but making what 
is left stout and woody until it has formed a bush so wide that no 
cow can reach the center from any side. Then the shoots in the 
Fig. 6o. Pasture with Cock-spur Thorns trimmed by cattle. 
center may carry the shrub upward, and this they immediately do. 
Every thorny pasture is full of these bushy shrublets biding their 
time. 
After the shrub has got beyond the stage where the cows can 
no longer keep its leaders down, the cows continue regularly to 
trim up the side branches until the pastures look much as if orna¬ 
mented by the topiary artist. The accompanying illustration is 
from a photograph of two plants that have been thus shaped and 
which to my mind show very plainly that thorns do not always 
protect. 
