ROOT FORMATION 



205 



Fig. 57. Rooting of lemon cuttings. Upper row, 8 hours in tap water; lower 

 row, 8 hours in indole-3-acetic acid (highest non-toxic concentration, 500 mg. 

 per liter). Photographed 17 days after treatment. (From Cooper, Plant 

 Physiol. 10: 789-794, 1935.) 



