1 8 THE WHEAT PLANT 



" White " wheats show a range of tint from an opaque creamy- white 

 to a translucent amber or yellowish shade ; the former, of which beautiful 

 examples are seen in Australian and some Asiatic wheats, possess " mealy " 

 endosperm, while grains of the amber tint have yellowish " flinty " 

 endosperm which is visible through the thin pericarp. 



Among " red " wheats the colour passes by fine gradation from the 

 palest tint to a dark brick-red or brown. 



The colour is most readily distinguished in grains with " mealy " 

 endosperm, for the latter provides an opaque chalk-like background, 

 against which the colour of the testa and pericarp are clearly seen. 



In many Squarehead forms of wheat with opaque chalky endosperm 

 the grains are an orange tint, a pale red testa being modified by the 

 yellowish-white pericarp : others, especially certain Chinese and Japanese 

 forms with a highly coloured testa and " mealy " endosperm, have rich 

 brick-red grains. 



Red grains with " flinty " endosperm are always darker than mealy 

 grains of the same variety. 



Where the grain is shrivelled or the pericarp discoloured by exposure 

 to rain or the attack of fungi, its true tint cannot be determined with 

 certainty. There is, however, usually little difficulty in assigning clean, 

 well-grown samples of wheat to their respective " white " or " red " 

 classes, except in certain forms of T. durum with translucent flinty endo- 

 sperm : among the latter wheats, pale " red " grains and amber-tinted 

 examples belonging to the " white " class can only be separated by the 

 most careful examination in a favourable light on a dark background. 



" HARD " " FLINTY " AND " SOFT " " MEALY " GRAINS. The endo- 

 sperm of certain grains of wheat, when cut transversely, is found to be 

 dense and translucent, resembling horn or flint in colour and transparency ; 

 to such the terms " flinty," " glassy," " horny," and " steely " have been 

 applied. Flinty grains are comparatively hard, with a somewhat vitreous 

 fracture, breaking into angular fragments, and market samples largely 

 composed of such grains are often designated " hard " wheats. 



So-called " soft " wheats have " mealy " or " starchy " grains, possess- 

 ing a very white, chalky endosperm ; the grains are opaque and com- 

 paratively soft, yielding a loose mass of floury meal when crushed. 



Sometimes the endosperm of a single grain is mealy in one part and 

 flinty in another : in such semi-flinty grains the apical portion is always 

 flinty, the white opaque part being found especially on the dorsal side 

 near the embryo, the mealiness being most conspicuous about the upper 

 edge and back of the scutellum, and extending inwards across the endo- 

 sperm to the furrow. 



In many instances the grains of an ear are either all flinty or all mealy, 

 but not infrequently some ears contain both forms ; in the latter cases 



