ROOTS 99 



91. ROOTS 



Object. To learn how a plant increases the absorbing 

 surface of its roots- 



Method. Plant some radish seeds on moist blotting- 

 paper, and when the roots appear note their surface. Ex- 

 amine them with a hand magnifier. Repeat the experiment, 

 using oats or corn. 



Visit a conservatory and examine the aerial roots of or- 

 chids. What takes the place of root hairs and why is this 

 modification beneficial to epiphyte plants ? 



Suggestion. Cut off a root tip of a germinating oat or 

 radish seed, mount it in a drop of water, and examine it 

 with a low power of the microscope. The character of a 

 root hair, the central cylinder, cortex, and root cap can read- 

 ily be made out. If a drop of eosin or methyl green is al- 

 lowed to follow under the cover glass, these structures will 

 be more easily seen. 



92. ROOTS 



Object. To find whether roots absorb water. 

 Apparatus. A wide-mouth bottle, cork, and a small plant. 



Method. Fill the bottle with water. Perforate the 

 cork and through the perforation pass the roots of the 

 plant. Insert the cork so that the roots are immersed in 

 the water and put some cotton around the stem to prevent 

 evaporation. 



Does the water go down? If so, where has it gone? 



Conclusion. State the inference you can draw from this 

 experiment. 



