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sions in regard to structure, imbibition, stratification and growth 
are yet theoretical. Our knowledge concerning the chemistry of 
starch is especially imperfect. It would be impossible to attempt 
to give a full summary of the author's investigations and results. 
The following are perhaps the most important conclusions: 
1. The starch-grain consists of amylose, which separates into 
a-amylose and #-amylose, amylodextrin, dextrin, isomaltose, and 
maltose. Of these substances amylose is perhaps the true starch- 
substance ; the others are the result of processes of inversion. 
2. Starch-grains are sphaero-crystals of amylose and amylo- 
dextrin. This is evident from their optical behavior. 
3. Amylose is split up by the starch-ferment diastase as fol- 
lows: with the aid of water, the amylose molecule is converted 
into two or more molecules of amylodextrin; this is converted 
into dextrin and isomaltose ; a further process of splitting up con- 
verts dextrin into maltose, while isomaltose may also revert into 
maltose. 
4. The starch-grain is porous. The pores are scarcely per- 
ceptible with the highest magnifying powers. The author makes 
a special attack upon Biitschli’s « Wabenstructur” theory. Among 
other things he says, ‘Es ist héchst interessant zu sehen wie ein 
So vortrefflicher Beobachter (Biitschli) die Schaum und Waben- 
structur mit welcher er sich eingehend beschaftigt, in die Ob- 
jecte hinsieht,” which, I think, expresses it rightly. 
The following are some of the more important conclusions in 
regard to the biology of the starch-grain. 
1. Starch-grains occur exclusively in the chromatophores. 
They may occur in any kind of chromatophore. The starch-grain 
of angiosperms originates and grows from the beginning until its 
final solution within a chromatophore. 
2. Every starch-grain is entirely enclosed by the substance of 
the chromatophore. The author points out the difficulty of de- 
monstrating the presence of the chromatophore substance. 
3. The form of the starch-grain is more or less dependent 
upon the form of the chromatophore. The chromatophore sub- 
Stance does not always form an even layer over the starch-grain. 
The thickest portion of the chromatophore always lies in contact 
with the thickest stratifications of the starch-grain. 
