IOWA ACADEMY OF SCIP^NCES. 



77 



THK RELATION OF FROST TO CERTAIN PLANTS. 



BY i,. 11. I'AMMEL. 



Most persons are familiar with the fact that some plants are much more easily 

 affected by frost than others. The slightest frost will affect plants like Pussly, 

 young corn, beans, twitch grrass. tomatoes, squashes, pumpkin, etc. I have 

 watched many plants for 80mn years, but the opportunity oF recording temperature 

 in close proximity to the plants have not heretofore been made here, though 

 doubtless some observers have recorded facts, but the references are not at hand. 

 Up to November 4 the following observations were made. In these tables dates 

 and temperatures are recorded only at 32 degrees and below. 



THEKMOMETEB FIVE FEET FROM THE GROUND. 



