GERMINATION. 171 



placed on moist sand for determining their germinating 

 power. The experiments were again repeated with 

 eleven other samples, to determine the influence of time 

 upon the heating. The conclusions were, that the 

 germinating power of beet seed submitted for three 

 hours to a temperature of 50 to 60 degrees C. was con- 

 siderably increased; the same seeds, at a temperature 

 of 115 to 120 degrees C. lost their power to germinate, 

 and this loss of vitality increased with increase of tem- 

 perature. A moist heat produces also a beneficial 

 effect, for seed, exposed to moist, hot air for six hours, 

 from 40 to 50 degrees C, had its germinating power 

 .considerably increased. However, changes occur at 

 70 degrees C, and with an increase of temperature the 

 vitality is completely destroyed. Consequently, it is 

 very important to keep in mind that there are certain 

 limits which should not be surpassed. 



Hot water is more destructive to the germinating 

 power of beet seed than is hot, dry or moist air. Seed 

 in hot water at a temperature of 60 degrees C. will no 

 longer germinate, and even at 55 degrees C. only three 

 or four out of 100 will give signs of life; as this limit is 

 not reached in the soil, it need not be dreaded. 



Moisture. 



The moisture of beet seed is an extremely vari- 

 able question, and while certain limits are fixed 

 when seeds are purchased in the market, the idea 

 is mainly to prevent fraud when the sale is by 

 weight, as it always should be. Furthermore, moist- 

 ened seeds lose their keeping powers; consequently, if 

 that system of fraud were allowed, the purchaser would 

 be the loser. Nobbe allows an average of 13.3 per 

 cent, moisture; Maercker admits that 20.5 per cent, is 

 not uncommon, while, at the other extreme, 4.4 per 

 cent, is considered an average, which limit is sim- 

 ply absurd. 



