104 ROOTS 



99. ROOTS 



Object. To study the effect of heat on the action of 

 roots. 



Method. Set a potted plant in a dish of ice water and 

 another of the same size in a dish of warm water so that the 

 flowerpots are immersed. Young radish, cabbage, tomato, 

 or coleus plants will do very well. Keep both plants in a 

 warm room where all other conditions are alike. 



After an hour or two examine both plants, observing all 

 parts. How do they differ in appearance? Now reverse 

 the plants, placing the cold one in the warm water and the 

 other in the ice water. 



After another two hours again observe the plants. Result ? 



Conclusion. State what may be inferred from this 

 experiment as to the most favorable conditions for root 

 action. 



100. ROOTS 



Object. To shoiv the effect of mutilation of roots on 

 the growth of the plant. 



Method. Young cabbage or celery plants will do very 

 well. Transplant two seedlings about four inches high into 

 flowerpots of the same soil. With the first plant take care 

 not to injure the roots and press the soil carefully around 

 them. With the second plant grasp the stem carelessly 

 between the fingers and merely pull it up ; put it into the 

 flowerpot and scatter soil on the roots. After one week 

 compare the two plants. How do they differ ? Why? 



Note. To prevent mutilation of roots seeds are sometimes 

 planted in egg shells filled with soil. They can be transplanted 

 without being dug up. The shell and all may be planted in the 

 ground, and thus the roots will not be disturbed. 



