THE GROWTH OF THE PLANT 



103 



Experiment 67 



Aim. — To find out in what part of the root growth 

 takes place. 



Method. — A broad-bean seed germinates in damp 

 sawdust or fibre. When the root measui-es about one 

 and a half inches the seedling is removed from the 

 sawdust, carefully washed and dried with blotting- 

 paper. The root is then marked by horizontal lines 



Fig. 54 



into one millimetre divisions (1 mm. = -^ inch approxi- 

 mately). The marks are made with Indian mk by 

 means of a small camel's-hair paint-brush. The ink 

 will not run if the root is properly dried. It will be 

 sufficient if a length of fifteen millimetres from the tip 

 is measured off. "' 



The seedling is then pinned to a strip of sheet cork 

 which is fitted into the cork of a gas-jar as described in 

 Experiment 56. 



