600 IOWA ACADEMY OF SCIENCE 



The author concludes that the strongest solution is decidedly 

 injurious, either when seeded immediately or after covering 

 12 hours, as in either case the formalin was kept in contact 

 with the seed much longer as compared with the other treat- 

 ments. "While it is apparent that the solution (one ounce to 

 one gallon) had no apparent affect field tests have demonstrated 

 that at times even this solution may cause a decreased stand. 



The variability in results might be attributed to other causes, 

 which raised the following questions: 



Do different varieties of oats offer different degrees of resist- 

 ance to formalin ? What percentage of the seed is killed by for- 

 malin of the strengths usually employed? Does formalin have 

 any stimulating affect upon germination? Are the seeds of in- 

 ferior quality more susceptible than those of medium or excel- 

 lent quality? Does the fatality increase with the increase of 

 the time of application? "While many tests have been made 

 bearing upon these points, they have usually been made with 

 only one or two factors in mind, and the results are neither 

 concordant nor conclusive. In order to determine some of these 

 factors a series of crucial experiments were planned with the 

 hope of gaining conclusive answers. 



In all cases 1,000 seeds of average quality were taken and 

 treated for twelve hours. They were treated with formalin of 

 the strength indicated and one cc. of the solution was employed 

 to 9.3 cc. of seeds, this being equivalent to the usual practice of 

 using one gallon of liquid to one bushel of seed. The seeds, 

 after being thoroughly wetted by the solution, were placed in 

 glass capsules, of suitable size, to prevent loss of formalin by 

 evaporation. Great care was taken to have the lots exactly 

 alike, except as regards the factor under observation. After 

 treatment the seeds were planted in flats in clean sifted sand 

 in rows one-half inch apart, with the seeds evenly distributed 

 in the rows. In this manner, it was possible to account for 

 every seed. The final record of germination was taken two 

 weeks after planting, since experience showed that all available 

 seeds germinated in that time. 



All seeds designated as average quality were secured by dis- 

 carding from a clean commercial sample of considerable size, 

 all foreign seeds and empty chaff, but retaining all actual oat 

 seeds, each of which, in case of any possible doubt, was inspected 



