422 



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



produce a slight lowering of the percentage germination by preventing the 

 germination of feebly germinable seeds. 



The effect of pricking the seeds is apparently injurious, for, as a general 

 rule, less of the pricked seeds developed than of the unpricked ones. In 

 addition, samples of all these seeds were tested for the presence of diastase 

 while in the resting condition, 5 to 20 grammes being used for extraction 

 according to Darwin and Acton's method. The precipitate was allowed to 

 act on starch solution for one hour, and then tested for reducing sugar. 



Considering the case of the wheat first, as set out in the following tables, it 

 will be observed that while age materially affects the germinating power of 

 the seeds, it does not apparently materially influence the quantity of diastase 

 enzyme present in the seed, nor its activity, at any rate up to an age of 

 20 years.* 



In every instance, strong reduction was produced by Fehling's test, and the 

 variations in the degree of reduction noted in the tables were extremely 

 slight, and might be due to differences between the samples when originally 

 harvested. 



The different samples of barley gave closely similar results, and the same 

 applies to the oats, rye, and maize. 



The oats exhibited the greatest amount of variation, and though in all 

 cases a distinct reduction was obtained on testing for diastase, the amount 

 present in some of the resting seeds was small. Slight differences in the 

 amount of reduction are in part produced by extraneous factors, such as the 

 strength and quantity of the solutions used, the fineness to which the seeds 

 are ground, and the detailed treatment during extraction. These results do- 

 not coincide with those obtained by Acton,f who found that an extract from 

 wheat grains which had been stacked for 28 years exercised no diastatic 

 action on thin starch solution. He offers the suggestion that the diastase 

 present in the freshly stored grains had been destroyed by oxidation, or by 

 the influence of micro-organisms. Thus reference to the two first cases of 

 oats cited in the tables shows that 10 grammes of fresh oats, with a 

 germination capacity of 100 per cent., produced exactly the same reduction 

 on testing as was produced by 10 grammes of oats from 8 to 10 years old, 

 with a germination capacity of nil, under as precisely similar conditions as- 

 possible. 



The least reduction was produced by maize, the strength of reduction in 



* Brocq-Kousseau and Gain (' Compt. Rend. Acad. Sci. Paris,' vol. 146, 1908, p. 545) 

 state that peroxidase enzymes appear in seeds up to 20 years of age and may persist in 

 some cases for 100 to 200 years. 



t ' Annals of Botany,' vol. 7, No. 27, September, 1893. 



