FIG. 12. 



To show where growth in length of the root takes place. 

 Forty hours before the photograph was taken the tip of the 

 root was l /\ inch from the lowest thread. The glass cover 

 was taken from this in order to get a good picture of the root. 



FIG. 13. 



Radish seeds sprouted on dark cloth. 



To show root hairs. 



