CELL-CONTEXTS STARCH. 



343 



consist of two layers, an upper and a lower one \ and the 

 collapsed vesicular bodies of an extremely fine but strong 

 and elastic membrane." Mr. Busk believes the hilum 

 to be a central opening into the interior of the ovate 

 vesicle. 



1, Nucleated Cells. 2, Stinging-nettle Hairs, Urtica Dioica. 3, Ciliated spores 

 of Conferva;. 4, Starch grains, broken by the application of heat. 5, Starch 

 from Tous-les-mois. 6. Starch from Rice. 7, Starch from Sago. 8, Imita- 

 tion Sago-starch. 9, Wheat-starch. 10, Rhubarb-starch, in isolated 

 cells. 11, Maize-starch. 12, Oat-starch. 13, Barley-starch. 14, Potato- 

 starch. 15, Section of Strawberry, cells ovoid, containing granular matter. 

 16, Section of Potato, with starch destroyed by fungoid disease. 17, Potato, 

 with nearly all starch-grains absent. 18, Section of Potato, cells filled with 

 healthy starch. (These starches are grouped for comparison.) 19, Mushroom 

 spawn, elongated cells. 



Nitric acid communicates to wheat-starch a fine orange- 

 yellow colour; and recently-prepared tincture of guaiacum 

 gives a blue colour to the starch of good wheat-flour. 



