60 DOMESTICATED ANIMALS AND PLANTS 
have the underground rootstock. Everybody knows that ordinary 
cutting or pulling avails nothing, for they merely send up new 
shoots from the buds already formed in the running rootstock 
under ground. If, however, this new shoot and leaf are killed 
by cutting off at once, and the next and the next treated in the 
same way as soon as they appear, the plant will die in time, for 
it has but a limited number of ‘“‘ buds” and a limited amount of 
food stored in the stem; and if it cannot soon get new leaves to 
the sun for more carbon, it must give up the fight and die. Plow- 
ing thoroughly once a week for a single season will kill any weed. 
This struggle from overcrowding is best seen in the growth 
of young trees in the forest. Many more seedlings will start 
than can possibly live, for a fully matured tree needs and will 
take a space from ten to fifty and in some cases even one 
hundred feet across. 
Accordingly when young trees stand thick a struggle at once 
ensues as to which shall overtop the others and get to the sun- 
light. The strongest will, of course, be the tallest and get the 
most light. This in turn gives it more carbon and greater 
growth, with still further advantage over its fellows, which 
manage to live as long as they can keep a few leaves in the 
sunlight, and then die when the failure, which is inevitable, 
really comes. 
It is interesting and almost pathetic to see the extent to which 
this struggle for sunlight and life is sometimes carried. The 
writer once saw a specimen that had recently died out of a 
thicket of young maples. It was thirty-six feet high, yet was 
but one and three-fourths inches in diameter at the largest place, 
so completely had its little growth been converted into height 
at the expense of size in the vain effort to keep its few leaves 
bathed in the precious sunlight. This tree never stood quite 
alone, but leaned helplessly against its stronger neighbors after 
the fashion of a vine. 
Among the trees that remain, the same principle applies as 
between the upper and the lower limbs. As new branches start 
