174 



Bulletin 80 



TABLE XIV («) 

 Squash roots grown in distilled water with CUSO4 



Cu p. p.m. 

 check 

 .01 



Elongation 24 hrs. 

 3.6 mm. 

 2.8 



Cu p.p.m. 

 .05 

 .1 



Elongation 24 hr.s. 

 1.4 mm. 

 2. 



Squash roots grown in distilled water with Cu(0H)2.CuC0; 



Cu p.p.m. Elongation 24 hrs. Cu p.p.m. 



check 3.6 mm. .05 



.01 3.8 .1 



Elongation 24 hrs. 

 3.6 mm. 

 3.8 

 Doubtful stimulation at .01 p.p.m. 



Elongation 24 hrs. 

 1.1 mm. 

 .4 



TABLE XIV (o) 



Com roots grown in distilled water with CUSO4 



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



check 8.7 mm. .05 



.01 10.9 .1 



Elongation 48 hrs. 

 4.7 mm. 

 1.5 



Corn roots grown in distilled water with Cu(0H)2.CuC0 



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



check 8.7 mm. .05 



.01 13.2 ,1 



Elongation 48 hrs. 

 3.3 mm. 

 2. 



These cultures, while somewhat fragmentary, afford excellent 

 indications of stimulating effects upon plant roots. Excluding 

 squash, which is not satisfactory material to work with, corn and 

 beans show consistent stimulations at very high dilutions. Meas- 

 urements in all cases are averages of about ten observations. 



TABLE XV 



SUMMAKY OF STIMULATION EFFECTS 



Character and strength in copper of 

 solution producing stimulation 



