370 



IOWA ACADEMY OF SCIENCE Vol. XXVI, 1919 



From an examination of the data and of the graph, figure 96, it 

 is apparent that the absorption by wheat placed in a formaHn solu- 

 tion and in water does not vary materially during a period of thirty 

 minutes. At the end of ten minutes greater absorption is present in 

 the seed placed in the formaldehyde but a revisal is present at the 

 end of fifteen minutes as seed in distilled water increases in weight 

 to a greater extent. However, after fifteen minutes imbibition is 

 approximately the same. 



The second part of this series of investigations was confined to 

 a study of the time of exposure to formaldehyde necessary to cause 

 a fall in the percentage of germination. The general plan then is 

 the same as has been previously set forth. The seeds were retained 

 in the glass stoppered containers after the formalin solution had 

 been poured off for varying periods from one to thirty-six hours, 

 when they were weighed. The data are given in table II. 



TABLE 11. 



DATA GIVING PERCENTAGE OF ABSORPTION AND GERMI- 

 NATION FOR WHEAT SUBJECTED TO FORMALDEHYDE FOR VARY- 

 ING PERIODS FROM ONE TO THIRTY-SIX HOURS. 



