76 THE VITALITY AND GERMINATION OF SEEDS. 



in a tube, respired quite freely. After the lapse of two years an 

 analysis of the confined air gave the following results: 



Per cent, 



Oxygen 14. 44 



Nitrogen 81. 74 



Carbon dioxid 3. 82 



These same seeds germinated 45 per cent and had increased T | 7 of 

 their original weight. 



In the experiments of the writer it was found that 40.1150 grams of 

 air-dried beans liberated 7.7 cc. of carbon dioxid in 370 days. The 

 concentration of the carbon dioxid in the flask at the time the gas was 

 drawn for analysis was 1.54 per cent. This sample of seed germinated 

 97 per cent, and there was only a very slight retardation in germina- 

 tion, which indicated that the vitality had not been materially reduced. 

 During this time there was a slight decrease in the weight of the seed 

 0.19 per cent. At the same time two check bottles were set up, one 

 containing 40.1184 grams of beans known to be dead, and the other 

 bottle containing nothing except air. Analyses of the air from these 

 two bottles gave the same results as samples of air drawn from the 

 laboratory. These preparations were kept in subdued light through- 

 out the experiment. 



That respiration may take place in the dark, that it is very intense 

 if much moisture be present, and that intensive respiration is accom- 

 panied by a rapid loss in vitality is shown by the following experi- 

 ments. On April 3, 1900, samples of beans, cabbage, carrot, lettuce, 

 and onion were sealed, each in bottles of 250 cc. capacity, and were 

 stored in a dark room which was maintained at a temperature of from 

 20 to 25 C. These samples were first carefully weighed and then 

 placed in a damp chamber for 175 hours, so that an additional quantity 

 of moisture could be absorbed. 



Control samples of air-dried seeds were also kept in sealed bottles 

 and subjected to the same subsequent treatment. After the lapse of 

 one year analyses of the confined gases and germination tests of the 

 seeds were made, the results of which are given with the general 

 details. 



Beans. Of beans, 24.9994 grams absorbed 4.70 per cent of water 

 while in the damp chamber. The respiration during the year was 

 equivalent to 2.5 cc. of carbon dioxid. The loss in weight was only 

 0.05 per cent, but the vitality had fallen from 100 to 86 per cent, as 

 shown by the control. 



Cabbage. Of cabbage seed, 10 grams, with an additional 9.79 per 

 cent of water, were used for this test. During the year this sample 

 of cabbage seed had given off 24 cc. of carbon dioxid, an equivalent of 

 2.4 cc. of carbon dioxid per gram of seed per year. The control 

 sample germinated 89 per cent, but this seed was dead. 



