1902-3.] The Chemistry of Wheat Gluten, 515 



Both gliadin and glutenin invariably give the reactions for organic 

 iron and phosphorus, but are not nucleo-proteids. Under the micro- 

 scope the gluten matrix in thin sections of wheat does not show any 

 indication of iron or phosphorus, and it must, therefore, be concluded 

 that the organic iron and phosphorus found in gluten are due to nucleins 

 or nucleic acid derived from the nuclei of the large endosperm cells. 

 Probably part is derived from nuclei of the aleuron cells, or of the 

 embryo cells, or from the nucleins present in the cytoplasm of the 

 embryo cells. 



Gliadin exists as such in the wheat grain, and the theory of its 

 formation by means of ferment action is not justifiable. Strong alcohol 

 mixed with flour and then diluted with water to a 70 per cent, solution 

 extracts gliadin from it ; boiling alcohol also extracts gliadin from flour 

 or bran. 



Glutenin exists as such in the wheat grain ; any manipulation that 

 will destroy the hypothetical ferment will coagulate glutenin, thus mak- 

 ing gluten formation impossible. 



Gluten formation is not merely a mechanical mixture of gliadin 

 with glutenin, but a definite physical state of the two mixing substances 

 is necessary. Coagulated glutenin with gliadin does not form gluten. 



There are probably several nucleins or nucleo-proteids in wheat, as 

 shown in the various ways phosphorus is distributed in the different 

 types of embryo cells. Organic iron is found only in the nuclei of the 

 endosperm, aleuron, and embryo cells, and in the cytoplasm of the 

 absorption layer, plumule and radicle cells. The proteid between the 

 aleuron grains shows the presence of organic phosphorus only. 



