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4. DEY MEMBRANES 



It is evident that the kerosene did not act uniformly on the grains 

 of corn which were subjected to the treatment. Some were killed, 

 some injured, while others showed no injurious effects whatsoever. 

 These conditions prevailed regardless of the period of immersion. No 

 length of treatment was found which directly killed or even injured 

 all the grains. This fact becomes significant when it is noted that the 

 kerosene treatment was varied from a mere dipping to continuous im- 

 mersion for a period of eight years. 



Rather early in my work it was suspected that the oil penetrated 

 the membranes of some grains more readily than those of others. 

 Some embryos had an oil-soaked appearance after the kerosene treat- 

 ment while others seemed free from the oil. 



To obtain further evidence of the permeability of the coats to 

 the oil, 200 grains of Champion White Pearl were placed in kerosene 

 colored with Sudan III. After 50 days' immersion the corn was re- 

 moved and superficially dried with a towel. One hundred of these 

 grains, taken at random, were cut transversely through the middle of 

 the embryos and carefully examined for the presence of colored oil. 

 Seventy-eight showed no trace of oil or color in the embryos; five 

 were slightly stained ; the remaining seventeen were deeply stained 

 and showed the presence of oil in considerable quantities. In no case 

 was there any evidence of oil in the endosperm. The remaining 100 

 grains treated with Sudan III kerosene, as above indicated, were left 

 exposed to the air for twelve hours and then planted in a 30% satu- 

 rated soil. In cutting through the 100 grains taken at random from 

 the 200 treated, it very soon became apparent that in most cases a 

 selection from external appearances alone could be made. This was 

 attempted before planting the remaining 100 of the treated grains. 

 From external examination these 100 grains were divided into three 

 groups : first, those seeming to be free from the colored oil ; second, 

 those showing slight traces of it ; and third, those in which the em- 

 bryos were deeply stained. The grains of these groups were planted 

 in separate rows in the culture pans and were kept under identical con- 

 ditions. Of the 76 grains of group one, all germinated and produced 

 normal seedlings. Nine out of 14 of the second group, germinated 

 but produced seedlings showing greater or less injury. One grain 

 from group three germinated, the seedling being decidedly weak. 



It has already been stated that the grains were carefully selected 

 before they were immersed in the oil. Any having visible defects 

 were rejected, but no selection was made after removing the corn from 

 the oil, with the following exception : April 20, a quantity of the 



