THE GLUTEN OF BREAD 



Protoplasm the Physical Basis of Life — Distributed in Form of a Network 

 Can Be Visualized by Study of Gluten in a Grain of Wheat 



PROTOPLASM is much talked 

 about and called the physical 

 basis of life, but when the layman 

 speaks of it, he often has no 

 definite picture in his mind. He knows 

 that it is said to be like an emulsion, 

 that it contains carbon, hydrogen, 

 oxygen, nitrogen, sulphur, and various 

 salts, that it is so complex as to baffle 

 any exhaustive analysis; and he thinks 

 of it as a mysterious substance known 

 to men of science, but quite outside his 

 own world of experience. 



This is not wholly correct. Most 

 peo])k', at least if they live in the 

 country, have at some time chewed a 

 few grains of wheat, spitting out the 

 bran and swallowing the dissolved 

 starch, until finally there was left on 

 the tongue a little pellet of tough, 

 elastic gluten. This gluten is one form 

 of ])rotoplasm. 



livery living cell must contain proto- 

 plasm — otherwise there can be no life 

 in it — and this ])rotoplasm is arranged 

 in the form of a network, as can 

 be conveniently seen by study of a 

 grain of wheat. The wheat kernel is 

 not a single cell: it consists of the 

 germ, or embryonic plant, and ten 

 or twenty thousand minute flour-cells 

 whose function is to supply nourish- 

 ment to the embryo while it is sjjrout- 

 ing. Flourcells and embryo are all 

 enclosed in a fiVjrous protective cover- 

 ing, which, when removed by the miller, 

 is bran. 



By careful handling, a single one of 

 these flour-cells can be taken out and 

 placed under the microscope. At first 

 sight it ajjpears to consist merelv of 

 starch granules. The starch is soluble 

 in water, and can be washed out l)y 

 boiling. It then a])ijears that the cell 

 has a complicated structure; that it con- 

 sists of a network of tough gluten, in the 

 interstices of which the granules of 

 starch were lodged. This structure is 

 beautifully illustrated in a drawing 

 350 



from a preparation made bv X. A. 

 Cobb (Fig. 8.) 



"Every flour-cell has all the common 

 constituents of the living cell, and all 

 are in a living state — each in its proper 

 position, and reacting as li\-ing matter. 



A 1 LO Lit -CELL 



A grain of wheat consists of the germ or 

 embryonic plant and ten or twenty 

 thousand flour-cells like the above, 

 which arc intended to sui)ply nourish- 

 ment to the embryo as it grows. The 

 fiour-ccll ajipears at first to be merely a 

 mass of starch granules of different 

 sizes, but when these are washed out, a 

 definite structure is revealed. Photo- 

 micrograph by All)crt Mann, about 200 

 times actual size. (Fig. 7.) 



There is the protoplasm with all its 

 comi)lexities, the nucleus with all its 

 directive possibilities; there is the starch 

 and the soluble portion together with 



