THE ROOTS 41 



observe the position of the roots. Note the direction 

 of the tips, and compare the number and length of 

 those in the moist end of the box with those in the 

 other end. This sensitiveness of roots to moisture, 

 by which they are attracted toward it, causes cisterns 

 and drains to become filled with the roots of clovers, 

 grasses, willows, and elms. 



46. Boots hend aivay from light. — The course 

 taken by roots in response to gravity and moisture 

 usually leads them deeper into the soil and away from 

 the light, but they have the power of bending away 

 toward darkness if the soil should be taken from 

 above them. This may be demonstrated in the 

 following manner : Tie a piece of muslin over a 

 tumbler and punch a number of holes in it with a 

 bodkin. Fill the tumbler completely full with water. 

 Lay some germinating seeds of the radish on the 

 muslin with the roots directed through the holes in 

 the cloth. Set in a window where it may receive a 

 strong light. Add enough water daily to keep the 

 vessel full. Observe the positions of the roots from 

 day to day. The tips will be seen to be directed 

 away from the point from which the light comes, 

 and they crowd toward the inner side of the tumbler. 



