440 Miss J. White. The Ferments and [Mar. 3, 



fresh seeds in the air dry condition as obtained from the seedsman exhibited 

 no respiratory activity whatever, although they contained quite appreciable 

 quantities of water. Among these non-respiring seeds Ricinus is included, 

 though in another species of Ricinus, Becquerel* states that an active inter- 

 change of gases does occur in the dried seeds, which he asserts to be a purely 

 non-vital chemical action. 



The experiments of Kolkwitzf carried out on barley illustrate the important 

 effects produced on the respiration of seeds by the presence of moisture in the 

 seeds. He found that — 



1 kilogramme barley grains at summer temperature gave off 3'59 m. mg. 

 of CO2 in 24 hours when 19 to 20 per cent, of water was present ; 



1*4 m. mg. with 14 to 15 per cent, of water ; and 



0*35 m. mg. with 10 to 12 per cent, of water. 



Becquerel* also discusses the effect of the presence of moisture in the 

 seeds on the respiratory activity of the seeds in his extensive researches on 

 the latent life of seeds, a short account of which also appears in the 

 'Comptes Eendus,' vol. 143, No. 26, December 24, 1906, p. 1177. 



Summary. 



The resting seeds of cereals such as wheat, maize, barley, oats, and rye all 

 contain diastatic, fibrin-digesting, and ereptic ferments in appreciable 

 amount. These ferments retain their activity without appreciable change in 

 stored dry seeds for 20 or more years, that is long after the power of 

 germination has been lost, which takes place in wheat after 11 to 16 years, 

 barley 8 to 10 years, oats 5 to 9 years, maize and rye over 5 years. The life 

 of the stored seeds is largely dependent upon the climatic conditions, a dry 

 climate favouring longevity. Thus South Australian wheat lasts longer than 

 that stored in Victoria, and still longer than that obtained from New South 

 Wales. The difference is, however, not shown strongly until after the 

 fourth or fifth year, South Australian wheat being still one-third germinable 

 after 9 to 10 years, whereas wheat stored in Victoria had entirely lost its 

 vitality by this time. 



No relation was noted between the vitality of seeds and the persistence of 

 enzymes in them, but since the enzymes persisted longer than the power of 

 germination, the question as to whether germination could take place in the 

 absence of any pre-existent enzymes remains to be answered. In any case 



* ' Comptes Eendus,' vol. 143, 1906, p. 974. 

 t ' Ber. d. Bot. Gesell.,' vol. 19, p. 285, 1901. 

 \ ' Ann. Sci. Nat., Bot.,' ser. 9, vol. 5, 1907. 



