140 



ETON NATURE-STUDY 



cork loosely into top of the tube, place a known weight upon the 

 top and see how much the seedling will lift. 



Other seedlings may be grown so that the roots hang freely in the 

 centre of a tube kept moist by a semi-cylinder of wet blotting-paper. 

 Lines drawn upon the root at equal intervals (with Indian ink) will 

 show very soon what parts of the root are lengthening. 



From photograph by Wilfred Mark Webb. 



FIGURE 133. A Seedling showing 

 growth when air is admittec 

 to the tube containing it. 



FIGURE 134. A Seedling kept in a 

 closely corked tube. No growth 

 to speak of has taken place. 



