GRASSES OF IOWA. 



119 



thirty-eight hours, but Otto* makes the statement that with 

 oxalic acid he succeeds in causing se^ds to germinate which 

 were between 20 and 40 years old. Bailey, f who treated a 

 large number of chemicals with substances as permanganate 

 of potash, chlorate of potash, etc., demonstrated that these 

 retarded rather than hastened germination. In a paper by 

 Pammel and Stewart| on the subject of corn and different 

 fungicides it was shown quite conclusively that the treatment 

 in every case was injurious. 



Pammel § had previously shown that corn roots, when treated 

 with a mixture containing copper salt, were injuriously affected, 

 the total amount of germination being retarded. These experi- 



Fig. 68. Copper compounds and the germination of maize. Strong ammonlacal 

 carbonate of copper. 



ments were conducted in the greenhouse. Dr. Walter H. 

 Evans, || in a compilation of the treatment of seeds with cop- 

 per sulphate, to prevent the attack of fungi, comments on this 

 experiment as well as others. Evans seems to question the 



•Balfour; Class book of botany. 3: 628. 

 tAnn. Rep. Mich. Agrl. Exp. 8ta. 1: 110. 1886. 



*The Influence of fungicides upon the germination of seeds. Agrl. Scl. 8: No. 5. 1894. 

 §Are copper salts Injurious? Bull. Iowa Agrl. Exp Sta. 16: 331. 

 OGopper Sulphate and germination. Bull. Div. Veg. Phy. and Path. U. S. Dept. 

 Agrl. 10: 14. 



