250 



and no further effort was made to keep the moisture content constant. 

 Water was added in sufficient quantities to keep the corn in good 

 growing condition. 



The method used for securing and maintaining the moisture con- 

 tent of the soil is not absolutely accurate. The limits of error, how- 

 ever, were certainly within 2%, which was sufficiently accurate for 

 the purpose intended. 



7. TKMPRRATURK 



During the periods of germination and initial growth the cultures 

 were kept in a basement room where the temperature varied between 

 23 and 28 degrees C. After the seedlings were well above the surface 

 of the soil the covers of the pans were removed and the cultures taken 

 to the greenhouse, where the corn was allowed to grow until it was 

 from five to six inches tall. It was then taken up and all abnormal 

 seedlings were carefully examined. 



III. Experimentation and Discussion 



1. EFFECTS OF THE PEEIOD OF IMMERSION AND THE 

 MOISTURE CONTENT OF THE SOIL 



As already indicated, the water content of the soil in which the 

 grains, after immersion in kerosene, are planted has a very marked 

 effect on germination. The data that follow in tables i to 4 inclusive 

 show the per cent, of germination and normal growth as affected by 

 the period of immersion in kerosene and the water content of the soil. 



The kerosene used was a product of the Standard Oil Company, 

 on the market under the trade name "Perfection." 



In all tests recorded in the tables, the grains were carefully se- 

 lected before immersing them in the kerosene, but no selection was 

 made after removing them from the oil. 



The time indicated under the heading "kerosene treatment" gives 

 the period during which the grains were immersed in the oil. In the 

 column "after treatment" is indicated the treatment of the grains after 

 removal from the kerosene and before planting. In every case where 

 it is not specifically stated to the contrary, the grains were superficially 

 dried with a towel immediately after removing them from the oil. 

 When this was not done it is indicated in the table by the word "none." 

 The grains in these instances were planted directly from the kerosene. 



A grain was considered germinated if it showed a decided growth 

 (i inch) of radicle or coleoptile. 



