Denniston—Growth and Organization of the Starch Grain. 675 
layers of starch, in the body of the grain are violet in color and 
fairly uniform in shade. 
In the parenchyma cells of the fleshy rootstocks of Dief- 
fenhachia seguina, large starch, grains are present. They are 
elongated in form, with the hilnm close to one end. In many 
of these grains, the effect of a change in position of the plastid 
is shown. In these grains the laminae are in two series which 
are often at nearly right angles to each other (Tig. 32). When 
stained with the triple stain, an orange layer is differentiated 
at the periphery and the interior layers are stained violet. 
The starch grains in the parenchyma of the false bnlb of 
Pliajus grandiflorus are large, and the hilum is situated near 
one end, often in a small projecting tip. The leucoplast in 
these grains is often distended by a linear crystal of calcium 
oxalate. A peripheral orange layer is differentiated by the 
triple stain. 
The starch grains of wheat, barley and rye are lenticular 
in form with a central hilnm. Both in material which has 
been fixed and in fresh material, an orange-staining peripheral 
layer may be demonstrated by the use of the triple stain. 
The starch grains from Zea mays are polygonal or rounded 
in form, with a distinct central hilum and concentric layers. 
The leucoplast is demonstrated with difficulty, but an orange- 
staining peripheral layer is present on many of the grains. 
In the endosperm of the seeds of Coix lacryma fobi, the 
starch grains have a polygonal form. The hilum is central, 
and the grains with but few exceptions show a broad orange- 
staining peripheral layer. In the germinating seeds of this 
plant, the cellulose cell walls are stained orange with the trip¬ 
le stain. It is probable that the cellulose of the cell wall 
is modified in some way to make it available for the use of the 
growing plant in germination. A similar orange-staining sub¬ 
stance is produced in the formation of the cell walls, as shown 
by Timberlake. 
Of seven different commercial starches prepared as chemi¬ 
cally pure starch by Eli Lilly & Co., two showed the peripheral 
layer in nearly all the grains; these were potato and tapioca 
starch. In wheat, bean, corn and oat starches, peripheral lay- 
