464 



C. Kraus^ made his observations on barley and describes the effect of 

 hail storms on the grain. He found many heads greatly bent backward and 

 turned, since, after the buds had been hit by hailstones, they were so bruised 

 that only the furtherest developed could free their tips from the outermost 

 leaf sheathing. Heads which had been hit directly were retarded in their 

 whole development; the kernels were lighter, not uniform and often tipped 

 with black. The weight of the heads was about 38 per cent, of the normal, 

 that of the grains about 43 per cent. Kraus found similar conditions in 

 two unbearded wheats, in which, however, because of the absence of beards, 

 the heads had worked their way more easily out of the uppermost leaf sheath. 

 Accordingly the weight of heads of wheat struck by hail was only about 



Fig-, rtl. The effect of hail on a blade of rye. (Orig.) 



£■ healthy Rreeii tissue, z tissue injured by a hail-stone, u adjoining healthy tissue, v completely 



destroyed hark of the blade with ruptured outer membrane («), h parenchyma of the blade, b 



vascular buadle. p ropes of cells resembling bast fibres. 



24 and 15 per cent, and the weight of the grains about 2-] and 17 per cent, 

 less than normal. 



When the hail storm occurs early in the year, i. e., perhaps in May, 

 many shorter green glades bent at the base are found later between the 

 ripening, ujtright ones covered with hail spots. The hailstone had probably 

 bent the plant and the blade required more time to straighten and this had 

 delayed ripening. 



WHieat seems to be the most robust. I observed after a hail storm in 

 June, 1905, that rye blades showed the injuries represented in Fig. 91, while 

 in the corresponding cell groups of the wheat, the inner tissue was split by 



1 Kraus, C, Wirkung von Hagelschltigen. Deutsche Landwirtschaftl.Presse 

 1899, Nos. 14-15. 



