2O THE FIRST BOOK OF FARMING 



ter in the shell. Prepare another egg in the same way, 

 but put colored water in the shell and clear water 

 in the bottle. The colored water in the shell will 

 pass through the skin and color the water in the 

 bottle. Sugar or salt may be used in place of the 

 red ink, and their presence after passing through 

 the membrane may be detected by taste. 



CONDITIONS NECESSARY FOR ROOT GROWTH 



We have learned some of the things that the roots 

 do for plants and a little about how the work is done. 

 The next thing to find out is : 



What conditions are necessary for the root to do 

 its work? 



We know that a part of the work of the root is to 

 penetrate the soil and hold the plant firmly in place. 

 Therefore, it needs a firm soil. 



We know that the part of the root which pene- 

 trates the soil is tender and easily injured. There- 

 fore, for rapid growth the root needs a mellow soil. 



We know that part of the work of the root is to 

 take moisture from the soil. Therefore, it needs a 

 moist soil. 



We know that part of the work of the root is to 

 take food from the soil. Therefore, it needs a soil 

 well supplied with plant food. 



We know that roots stop their work in cold 

 weather. Therefore, they need a warm soil. 



Another condition needed by roots we will find 

 out by experiment. 



