486 
AMERICAN JOURNAL OF BOTANY 
[Vol. 55 
the results obtained, and it seemed from this that any other carbohydrate 
in which there was uniform atomic arrangement would also give lines due 
to reinforcement of the reflected waves. If, however, the atoms were not 
uniformly arranged, lines should not appear, and in order to demonstrate 
this, another carbohydrate, dextrin, which is generally considered amor- 
phous, was photographed along with the cane sugar. An exposure of 1 8 
hours was given. The lower half of figure 5 shows the picture obtained 
from this amorphous substance, in which the rays are merely scattered, 
not reinforced at any single place. The atoms in air give the same sort of 
Fig. 6. Air. 
scattering, but much less intense, as shown in figure 6, with an exposure 
of 18 hours. 
Reflections from Starch Grains 
After these preliminaries, in which it was shown that the apparatus 
would produce lines with a crystalline, and none with an amorphous, sub- 
stance; that the principal lines were a lines; and that the exposure for 
Fig. 7. Above, potato starch; middle, cassava starch; below, corn starch. 
