56 Notes from the Physiological Laboratory 



constituents will remain in situ, and entirely unal- 

 tered. The same result may be obtained from a 

 somewhat more prolonged digestion of the unboiled 

 section. A section of wheat-grain thus treated will 

 exhibit throughout its entire central portion close- 

 meshed gluten net-works, which become slightly 

 denser toward the cortex of the grain. The pro- 

 teid character of these reticuli is here, as in the first 

 method, susceptible of micro-chemical demonstration. 

 Upon the application of Millon's reagent to such a 

 section, a relatively very faint coloration, indicating 

 the presence of albuminoids, is noticeable in the 

 "gluten-cells," while the gradual condensation of 

 the gluten of the endosperm, as the fourth layer is 

 approached, is evident even to the unaided eye. 



The fact that the gluten net-works become denser 

 toward the periphery of the endosperm, together 

 with the presence of non-albuminoid nitrogenous 

 compounds in the perisperm, explains the notable 

 percentage of nitrogen found in bran as ordinarily 

 roughly removed. 



The small proportion of albuminoids present in 

 the cells of the fourth layer as evidenced by their 

 feeble response to the proteid tests, together with 

 the very considerable quantity of gluten which we 

 have shown to exist in the central four-fifths of the 



