MOVEMENT OF SOIL-MOISTURE 145 
diately destroys the conditions of equilibrium formerly 
existing, for the moisture is not now uniformly dis- 
tributed. Consequently a process of redistribution 
begins which continues until the nearest approach 
to equilibrium is restored. In this process water 
will pass in every direction from the wet portion of 
the soil to the drier; it does not necessarily mean that 
water will actually pass from the wet portion to the 
drier portion; usually, at the driest point a little 
water is drawn from the adjoining point, which in 
turn draws from the next, and that from the next, 
until the redistribution is complete. The process 
is very much like stuffing wool into a sack which 
already is loosely filled. The new wool does not 
reach the bottom of the sack, yet there is more wool 
in the bottom than there was before. 
If a plant-root is actively feeding some distance 
under the soil surface, the reverse process occurs. 
At the feeding point the root continually abstracts 
water from the soil grains and thus makes the film 
thinner in that locality. This causes a movement 
of moisture similar to the one above described, from 
the wetter portions of the soil to the portion being 
dried out by the action of the plant-root. Soil many 
feet or even rods distant may assist in supplying 
such an active root with moisture. When the thou- 
sands of tiny roots sent out by each plant are re- 
called. it may well be understood what a confusion 
of pulls and. counter-pulls upon the soil-moisture 
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