226 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



the radicle and especially the tip are deeply penetrated 

 by the HgCl 2 . This is evidently due to the micropyle 

 being open and readily allowing the alcohol to pass in 

 and penetrate the tissue of the radicle, the apex of the 

 radicle being permeated soonest, because the alcohol comes 

 first into contact with it. 



Using the same method of experimentation it can 

 readily be shewn that Haricots are much more permeable 

 by alcohol than Peas are. Hence it is that one to two 

 days immersion in alcohol is sufficient to kill Haricots, 

 whereas Peas resist for a much longer period. The 

 rapidity with which the alcohol penetrated the Haricots 

 experimented with and destroyed their vitality was due 

 partly to the fact that they contained a larger percentage 

 of uncombined water, than did the Peas. 



In one experiment a number of Peas were placed in a 

 quantity of 50 p. c. alcohol which little more than covered 

 them. In a fortnight a little more than half of the Peas 

 were soaked through and had become soft and slightly 

 swollen. These Peas absorbed much more water from 

 the mixture than alcohol, the consequence being that 

 the percentage of alcohol was now much higher. All of 

 the soaked Peas were on being planted found to be incap- 

 able of germination. The unsoaked remainder were 

 found to be only very gradually affected by the alcohol in 

 which they remained. Thus after 3 weeks 60 p.c. and 

 after 6 weeks, 40 p.c. were still capable of germination. 

 These numbers are high because all weakly seeds and 

 those with more permeable coats had been previously 

 weeded out, the percentages remain high even after pro- 

 longed immersion because the increased strength of the 

 diluted alcohol is favourable to the preservation of the 

 vitality of the seeds. Peas can withstand immersion in 

 a mixture of 10 of alcohol to 1 of water for much longer 



