CELLS.— STARCH. 
29 
rupture of the granules and the liberation of starch, 
gum or dextrine. For this reason the starch granules 
FIG. 19 . 
a, Granules of Wheat-starch ; b , Sag o -meal ; c, Rice-starch ; d, Potato- 
starch ; e, Tons les mois ; f bursting of starch grains on the application of 
heat ; g, isolated cells of the Rhubarb containing starch granules. 
almost wholly disappear in boiled potatoes. When 
examined microscopically, starch is found to consist of 
more or less oval granules of various sizes, having 
definite and peculiar characters in different plants ; thus 
in the Tons les mois , Fig. 19, e, they are of very large 
size; in the Potato , Fig. 19, d, they are much smaller; 
and in the Rice , Fig. 19, c, are so very minute as to 
require a power of two hundred and fifty diameters to 
discover them. 
