157 



therefore, indiscriminately classed as " poor wheat." When this poor 

 wheat was used for seed it sometimes yielded good croi)s and some- 

 times failed to produce any crop. In many cases this difference in re- 

 sults was thought to he purely accidental, or, in case differences in the 

 seed used were observed, poor returns were attributed to a lack of vi- 

 tality in the injured grain or to the slow growth of grain from "frozen'^ 

 seed. But the fact generally lost sight of was that the causes which 

 produce "poor wheat" are different in different cases, so that really 

 there are more or less distinct classes of such wheat, which, if used for 

 seed, will give diverse results. The author of this article has attempted 

 a classification of the varieties of " poor wheat," according to the cause 

 of the injury to the grain, into bleached, rusted, blistered, and frozen , 

 wheat. 



Bleached wheat is defined as wheat which after harvest has been ex- 

 posed to rains and the heat of the sun until the outer envelope of the 

 grain is opaque and brittle. Ordinarily this does not affect the useful- 

 ness of the wheat for seed. Busted or blighted loheat is more or less 

 shrunken in appearance, and is usually of a deeper amber color than is 

 normal. The proportions of its chemical constituents are somewhat 

 changed, though their properties remain the same. The rusted wheat 

 of 1888, as far as examined, contains more than the normal amount of 

 gluten and protein and less of starch. " It is a poor wheat for milling 

 because of the bad condition of the hull," but if not too much injured 

 may be used for seed, as is indicated by the results of the experiments 

 here reported. Blistered wheat retains its normal amber color, but has 

 a brittle hull, and in many cases contains more gluten and protein and 

 less starch than sound wheat. "As blisters may be caused by other 

 means than frost, and even after the wheat is cut, it is not correct to 

 call all such wheat frosted.-^ Except in extreme cases, it may be safely 

 used for seed if well cleaned. Cured wheat is not affected by the lowest 

 temperature which occurs in Minnesota, but a temperature only a few 

 degrees below freezing affects immature and uncured wheat. " Wheat 

 well into the ' dough ' stage, if subjected to a temperature below freez- 

 ing, may be blistered (frosted), but when 'in the milk' the same tem- 

 perature produces /V'02;e» wheat." Frozen wheat "is badly shrunken, 

 has lost the normal translucent amber color, is of an opaque, bronzed 

 appearance, and has had the com])osition of its chemical constituents 

 changed, as well as the internal structure of its cellS destroyed." The 

 grain contains less gluten, and the quality of the gluten is seemingly 

 injured. It would seem that the albuminoid which gives tenacity to 

 the flour is altered. Such wheat deteriorates greatly after being har- 

 vested. When used for seed the crop is deficient in iirotein and in 

 gluten, and its gluten is of poor quality. Fermentation may set in later 

 on and the chemical constituents be further changed, as was the case 

 in jMinnesota during the winter of 1888-89, so that the frozen wheat 

 when planted in the spring was in a much worse condition than whea 



