MICHIGAN ACADEMY OF SCIENCE. 81 



and bacteria spores, even such fungus liypliae as may have penetrated 

 part way into the seed-coat. From wliat I knew of the ])roi;erties of 

 cleaning fluid, 1 liad no idea tliat any seeds were so resistant to its 

 action. For instance, Lupine immersed in it for five hours and fifteen 

 minutes still gave 52'/f of good seedlings. Up to about two hours im- 

 mersion Lupines gave in i)ractically every case, about 100%, of good 

 seedlings. Peas were also more resistant than was expected. After six 

 minutes exposure, 88% of good seedlings were obtained; and after forty- 

 five minutes immersion, the yield was still 70% . Wheat was found to be 

 rather sensitive to the action of cleaning fluid. After seven minutes 

 exposure it yielded only 28% of good seedlings. Corn was found to be 

 more resistant than Wheat but not so resistant as Lupines or Peas. After 

 seventeen minutes exposure, 88% of good seedlings of Corn were ob- 

 tained; but from there on the percentage of germination fell rapidly. 

 Thus, after twenty minutes exposure, only IGOr of good seedlings were 

 obtained and, after twenty-five minutes exposure only 4%. Mustard 

 was slightly more resistant than Wheat. After a ten minutes exposure, 

 56% of good seedlings were obtained. 



The second disinfectant em})loyed was mercuric chloride. To prevent 

 the adhesion or air-bubbles to the seeds, or a thin layer of air, the seeds 

 were first dipped in 70% alcohol, then thoroughly rinsed in 

 water to remove the alcohol and finally placed in the mercuric 

 chloride. The concentration of mercuric chloride employed varied from 

 one gram of mercuric chloride in one thousand cc. of water to one gram 

 in fifteen cc. of water. When Lupines were immersed in a one to two 

 hundred and fifty solution for fifty minutes, 100% of good seedlings 

 were still obtained. Beyond that concentration and length of immer- 

 sion the percentage steadily decreased, until, at a concentration of one 

 to fifteen for one hour and fifteen minutes it had dropped to 52%. 

 For Peas a one to five hundred solution only was used. The yield of 

 good seedlings, after a thirty minute immersion was SS% ; and after a 

 fifty minute immersion it was 04%. Wheat was found to be much 

 more sensitive to mercuric chloride than either Lupines or Peas. After 

 a thirty-minute immersion in a one to five-hundred solution, only 52% 

 of good seedlings were obtained ; while after an immersion of ten min- 

 utes, the yield was 92% . Corn was found to be more resistant to the 

 action of mercuric chloride than Wheat. After an immersion of thirty 

 minutes in a one to five-hundred solution, the yield of good seedlings 

 was 68% ; but, in a one to two-hundred and fifty solution, after the 

 same length of time, the yield was only 20%. Miistanl, after an im- 

 mersion of ten minutes, in a one to one thousand solution yielded 

 76% of good seedlings. When the concentration was increased to one 

 to five hundred and the time to thirty minutes, the percentage dropped 

 to eight. Before planting in the germinator, the seeds were thoroughly 

 washed in several changes of water for about an hour. 



The third disinfectant employed was potassium dichromate. The con- 

 centrations employed varied from N / 2 to N / 1000 ; and the length of 

 immersion varied from fifteen minutes to an hour. As in the case of the 

 other disinfectants, the yield of Lupine was relatively high, since the 

 yield was still 84% after an immersion of one hour in an N/2 solu- 

 tion. The highest concentration found practicable, in the case of Peas 

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