246 



Illinois. This work was not completed, but from the results obtained 

 and from the report published by Professor Forbes, Professor Hottes 

 was led to believe that the physiological aspects of the subject were 

 of sufficient interest to warrant a more thorough investigation, and it 

 was at his suggestion and under his direction that the work herein 

 described was undertaken. It is with pleasure that I acknowledge the 

 helpful advice and constructive criticism offered by Professor Hottes 

 during the progress of the work. 



II. Methods 



In a series of initial experiments an attempt was made to learn 

 something of the conditions which affect the germination of corn after 

 immersion in kerosene, and thus to discover, if possible, the causes of 

 the "perplexing discrepancies"referred to by Professor Forbes. Very 

 early in this work it became apparent that the highest per cent, of 

 germination could be secured only when the oil on the surface of or 

 within the grain had been reduced to the minimum. The effect of the 

 oil became especially marked when the corn was placed under condi- 

 tions for germination with more than the usual amount of water pres- 

 sent. These preliminary experiments further showed that the pres- 

 ence of water in the grain at the time of immersion in kerosene was 

 responsible in no small degree for the wide variation in the per cent, 

 of germination. 



I. ELIMINATIOX OF THE OIE 



The superficial oil was removed from the grains by careful wip- 

 ing with soft, absorptive towels immediately after removing them 

 from the kerosene. The grains were then imbedded in desiccated 

 powdered clay or plaster of Paris to remove as much of the remain- 

 ing oil as possible. The same result was accomplished, and much more 

 simply, by placing the corn on dry filter-paper exposed to the air to 

 allow the kerosene to volatilize. In a few instances when the corn had 

 been immersed for long periods of time the gummy coating formed on 

 the outside of the grain was dissolved off by washing vigorously for 

 a few minutes in chloroform. Acetone was also tried for the same 

 purpose, but it proved to be injurious to control grains and its use was 

 discontinued. Since exposure to dry air at room temperature, 23 to 

 28 degrees C, gave results in no wise inferior to the other methods 

 used for eliminating kerosene, it was used almost exclusively in all 

 cases where the elimination of the oil was called for. 



