C. H. Bailey 433 



formed largely during the early stages of the development of the kernel, 

 and the endosperm structure is rapidly laid down during a comparatively 

 short time preceding maturity. Any condition which interferes with the 

 deposition of material in the endosperm during the later stages of kernel 

 development reduces the quantity of potential flour material without 

 reducing the amount of fibrous seedcoat in like proportions. A plump 

 well-filled kernel accordingly yields more flour than does a shrivelled 

 one. The comjjarison on the basis of kernel volume must be restricted 

 to the same type or variety, since hereditary influences affecting the 

 shape of the kernel, particularly its length, would aft'ect the volume and 

 weight without similarly afiecting the ratio of endosperm to total 

 weight. 



To ascertain the relation between the kernel volume and the actual 

 percentage of endosperm, samples were taken from a field of blue stem 

 wheat at six stages of growth, beginning about ten days after flowering 

 and at intervals of three days thereafter until the grain was nearly ripe 

 enough to harvest. The kernels were at once removed from the heads, 

 and the endosperm material dissected out of 100 kernels. The non- 

 endosperm structures were dried to constant weight and 300 entire 

 kernels were similarly dried. The difl^erence in the weight of the kernels 

 and of the non-endosperm material was regarded as the weight of the 

 endosperm, since the latter was of such a sticky character that a loss 

 was experienced in collecting it. The volume of the dried kernels was 

 then determined by displacement in toluol. Table I shows the percent- 

 age of endosperm to increase fairly regularly from 62-6 per cent, when the 

 kernels occupied a volume of 9-897 c.c. per 1000, to 81-7 per cent, when 

 the kernel volume was 21-372 c.c. per 1000. 



Table I. Relation between the kernel volume and the weight and 

 percentage of endosperm. 



Volume per Endosperm per 



1000 kernels 1000 kernels Endosperm 



c.c. grams Per ct. 



9-897 0-7950 62-6 



12-317 1-1443 66-6 



16114 1-.5682 69-8 



17-871 1-7826 71-2 



19-417 2-1275 76-9 



21-372 2-4.576 81-7 



The volume of the kernel may vary widely in the same type or variety 

 of wheat when grown under different conditions. Thus hard spring 

 Journ. of Agrio. Sci vu 29 



