PLATE 21 
A. —Relation between percentage of seed-coat injury and degree of injury from a 
5-minute exposure to a i-pound to 4-gallon solution of copper sulphate: i, harvester- 
thrashed seed, with 30 per cent of seed coats broken, germination 86 per cent; 2, 
harvester-thrashed seed, with 95 per cent of seed coats broken, germination 42 per 
cent; 3, hand-thrashed seed, seed coats unbroken, germination 98 per cent. 
B. —Susceptibility of wheat and barley to long exposure to a saturated copper- 
sulphate solution: 1, Early Baart wheat exposed 6 hours, germination 80 per cent, 
2, Early Baart wheat exposed 10 hours, germination 80 per cent; 3, Early Baart wheat, 
control, untreated, germination 95 per cent; 4, Turkestan barley, control, untreated, 
germination 100 per cent; 5, Turkestan barley, kernels stripped from rachis, exposed 
6 hours, no germination; 6, Turkestan barley, kernels left attached to piece of rachis 
during treatment, exposed 6 hours, germination 90 per cent; 7, Turkestan barley, 
kernels stripped from rachis, exposed 10 hours, no germination; 8, Turkestan barley, 
kernels left attached to piece of rachis during treatment, exposed 10 hours, germina¬ 
tion 90 per cent. 
