46 Scientific Proceedings, Royal Duhlin Society. 



be due to a respiratory enzyme being active after the cells have been 

 poisoned by chloroform or toluene, but not after formaldehyde poisoning. 

 This evolution of CO2 was also found in the case of desiccated beans heated 

 to a few degrees above 100°C., when moistened as described. A copious 

 precipitate was observed after six hours, but no experiments were tried 

 over a shorter period. All these oxidation experiments were carried out at 

 about 12°0. 



Sttmmary. 



1. Bean seeds, living or dead, take up the same quantity of water in 

 their initial stages. 



2. The final weight reached, whether living or dead, is independent of 

 the presence of potassium nitrate, except in so far as the salt present alters 

 the density of the water. 



3. The rate at which distilled water is taken up is not greater than the 

 rate at which the salt solution is absorbed, any difference which may exist 

 being masked completely by tlie variations between apparently similar seeds 

 under similar conditions. 



4. Seeds placed in potassium nitrate solution, and then in pure water, 

 lose weight ; their final weight is then what it would have been had they 

 been placed direct in pure water. 



5. Titrations show that bean seeds placed in normal HaSOi, decinormal 

 iodine, and decinormal sodium chloride produce no concentration of these 

 solutions. The chloride remains almost unchanged. The iodine is de- 

 colorized. The H2SO4 is to a small extent diluted ; a very sniall amount is 

 neutialized by extractable alkali, while the tissues of desiccated beans 

 neutralize 1'47 per cent, of their weight of H,S04. 



6. These facts prove that there is no semipermeable membrane in bean 

 seeds till germination begins and the cell-protoplasm acts as sucli, and that 

 there is no difference in absorption between living and dead seeds until 

 after germination. The forces concerned are those of capillarity and 

 imbibition in the initial stages, but of osmosis after germination. 



7. The evolution of OO2 may be detected less than two hours after the 

 air-dried seeds have been first moistened. CO2 may be detected with living 

 seeds, and with those killed by chloroform. 



I wish to thank Dr. H. H. Dixon for his constant advice and for every 

 facility in obtaining apparatus and material. 



