0)1 the Vitality of Farm Seeds. 169 



growth of the emliryo plant. A machine, the principal part of 

 which was a cylinder lined with sharp steel points, was made ; 

 in action the cylinder was rotated rapidly, and the seeds in 

 l^assing through were pelted against these points with a force 

 which rasped the surface of the hard seeds and did no hiirt to 

 the others. A similar machine was made in England, at my 

 suggestion, with the result that clover seeds may be purchased 

 with a guaranteed germination of 1'<S or 100 per cent. This 

 gain was clearly established by these experiments, and the 

 "dressed" seeds were discontinued after the eighth year. 



These discontinued samples being deducted, there remain 

 thirty- five different kinds which have been tested year after 

 year till, one after another, they lost their vitality. In this 

 present year — 1911 — the Black Oat, which had outlived all the 

 others, has failed to show any signs of life, though over 300 

 grains were tested. 



The samples have been kept during the sixteen years in the 

 original paper bags, and have occupied two close-fitting drawers 

 in a cabinet placed against an inner wall of my laboratory. 

 Each year they have been regularly tested in the germinating 

 case, kept at a temperature of 70" to 80" Fahr., on plates of 

 porous porcelain, or between blotting paper, and the germinating 

 seeds have been removed day after day, and their number 

 recorded. A diagram showing the progress of the experiments 

 was prepared some years ago and exhibited at the Society's 

 Annual Shows, being brought up to date each year. 



The final results are shown in detail in the tables and 

 diagrams inserted in this paper. It should be noted that the 

 germination of seeds in the eighth year is in many cases below 

 that of the same sample in the ninth year ; this is evidently due to 

 some unrecognised unfavourable condition vitiating the experi- 

 ments in that year. The only two seeds which showed complete 

 loss of vitality in that year were the two smaller fescues. 



I. Cereals. — In the case of barley and Avheat the germination 

 is but little affected during the first five years, but thereafter 

 a rapid loss of vitality occurs and proceeds at an increasing rate 

 till, in the tenth year, no live seeds remain. The curve shown 

 by the oats is quite different : not until after the ninth year do 

 they show any serious loss of vitality, and in another five yeai'S 

 the white oats had no living seeds left, though the black oats 

 germinated for two years longer. This group of cereals gives 

 us the key to the results of the whole experiments. The 

 difference between wheat and barley on the one hand, and 

 oats on the other, is the greater protection afforded to the 

 ^^mbryo of the oats by the fact that in its case the glumes, 

 which fall off as chaff in the wheat and bai'ley, remain attached 

 to the seed. It will be seen in the experiments that the retention 



