Toxicity of Copper to Plant Roots 173 



TABLE XIV (70 

 Corn roots grown iu distilled water with Cu(0H)o.CuC03 

 Cu p p m. Elongation 48 hrs. Cu p.p.m. Elongation 48 hrs. 



Check 27.6 mm. .05 5.7 mm. 



.01 1.8 -1 ^-^ 



No stimulatiou; eccentric results. 



TABLE XIV (i) 

 Beau roots grown in well water with Cu(OH)2.CuC03 

 Cu p p m Elongation 48 hrs. Cu p.p.m. Elongation 48 hrs. 



u 1 '7 ,i,,i, 1 6. mm. 



check -2. nim. ->• 



.05 6. -5 -8 



Showing stimulation at .05 to .1 p.p.m. 



TABLE XIV (,;■) 

 Bean roots grown in distilled water with Cu(0H)o.CuC03 

 Cu p p m Elongation 48 hrs. Cu p.p.m. Elongation 48 hrs. 



che'^k 3. mm. .1 3.1mm. 



.01 3. .3 1-6 



.05 3.7 



Showing no stimulation. 



TABLE XIV (Ic) 

 Squash roots grown in well water with Cu(0H)o.CuC03 

 Cu p p m. Elongation 48 hrs. Cu p.p.m. Elongation 48 hrs. 



Check 2.4 mm. .1 5.7 mm. 



.05 4.9 .5 -4 



Showing stimulation at .05 to .1 p.p.m. 



TABLE XIV (0 

 Squash roots grown in distilled water with Cu(0H)..CuC03 

 Cu p p m. Elongation 48 hrs. ' Cu p.p.m. Elongation 48 hrs. 



eheck 3.3 mm. .05 3.1mm. 



.01 3.3 .1 2.1 



Showing no stimulation. 



TABLE XIV (m) 

 Bean roots grown in distilled water with CuSO^ 



Cu p p.m. Elongation 48 hrs. Height of tops 



1 2.9 mm. 87 mm. 



'.3 1.2 91 



.5 .6 85 



Bean roots grown in distilled water with Cu(0H),.CuC03 



Cu p p.m. Elongation 48 hrs. Height of tops 



1 2.9 mm. 98 mm. 



".3 1. 88 



.5 .6 84 



Showing same behavior with CuSOi and Cu(0H)o.CuC03. 



