Denniston—Growth and Organization of the Starch Grain. 687 
grain, as substances which we know are not formed of radially 
placed elements show radial cracks when crushed in this way. 
The experiment was next tried of crushing the unstained 
grains and then staining with gentian Violet and orange; it was 
found that much of the inner portion of the grain takes the 
orange stain, only a few layers at the outside taking the violet. 
The natural inference drawn from the result of the above 
experiments is that the orange does not stain the inner parts of 
the intact starch grain because it does not reach them, hut on 
the other hand it must not be supposed that the orange layer 
at the outside of the grain is simply the effect of the washing 
in of the orange. On some of the crushed grains which stain 
orange in the interior there is a peripheral orange layer, and 
on others there is not. It is to he remembered, also-, that the 
width of the orange layer does not vary proportionally to the 
length of time through which the orange is allowed to act on 
the grain. If the grain is stained for five minutes each in 
violet and orange, the orange peripheral layer is differentiat¬ 
ed when present, and there is no essential change in appearance 
though the time of the exposure to orange he doubled. 
The appearance of the orange-staining material in the in¬ 
terior of the grain seems to indicate that this portion of the 
grain is also somewhat different in composition from the periph¬ 
eral violet layers, and it is quite probable that we have in 
the interior of mature starch grains a change taking place 
which results at the same time in a loss of laminated structure. 
The exact nature of this change is difficult to determine ex¬ 
perimentally, but it may well be a change from a less to> a more 
soluble condition; if we can accept Meyer’s conclusion that the 
starch grain is made up of amylose and amylodextrine, it is 
possible that this portion of the grain contains a larger propor¬ 
tion of the more soluble amylodextrine. Fischer (10) has 
found that this portion of the grain is in a semi-fluid condition 
in grains soaked in water. 
In a preparation made from a grain of wheat which has be¬ 
gun to germinate, the starch grains are more or less corroded. 
Often the starch grains will be corroded in such a way that 
they will appear as if cut off on one or more edges (Figs. 40, 
