CH. I.] SOWING. 9 



Stead of passing into saccharine matter, is converted 

 into acetic acid. 



As it is imperative that eveiy seed should have 

 nearly attained to ripeness before it acquii'es the power 

 of germinating, and that the more perfect the ripeness 

 the more perfect and the more healthy that germina- 

 tion, so is it equally ceitain, that the length of time it 

 retains the power of germination differs in almost every 

 plant. The seed of the coffee shrub loses all vege- 

 tative power, unless sown within a few weeks after it 

 has been gathered, whilst that of the melon improves 

 by being stored for one or two years, and celery re- 

 mains capable of germinating for five times the last- 

 named period ^. These and all other instances within 

 my knowledge demonstrate, that the more starchy 

 and other matters into which nitrogen^ does not enter 

 as a constituent, which a seed contains, the longer v61\ 

 it retain vitality ; and two familiar instances are com- 

 mon rice and the kidney bean. Eice contains 85 per 

 cent, of starch, and will retain its vegetative powers 

 for many years ; whilst kidney beans, which contain 



* Melon seeds^ by keeping, improve only in the sense in which 

 gardeners consider the plant improved, viz. less of stem is produced, 

 and the fruit is matured earlier. Whatever checks the develop- 

 ment of the early organs, the radicle and plumule, produces this 

 effect, and this is effected by age in the melon seed ; its starchy 

 component diminishes in quantity, being gradually converted into 

 albumen. This is less easily transmuted to the soluble matters 

 necessary for the nourishment of the parts first developed. 



^ Nitrogen, a gas present in most animal matters. 



