56 BOTANICAL GAZETTE. | March, 
starch is the only organic matter formed by the chlorophyll 
cells; in fact, it is known that oil is often the product of this 
Sugars are as likely to be formed in the leaf of the plant as 
starch.? en we remember how easily starch is detected 
in most minute quantities and how easily sugar is missed 
even when present in much larger quantities, we do not Wons | 
der that vegetable physiologists have supposed that starch 1s 
the first carbohydrate formed in the leaf and that all the others 
are derived therefrom. The explanation which is made of 
the translation of the starch from the point of its formation to 
the localities where it is stored is as follows: 
Take, for instance, the formation of starch in the germ ofce- 
reals. We are taught that the starch first formed in the leaves 
is changed into sugar and in this soluble state carried through 
the plant until it reaches the seed. This sugar, reaching the 
point where the seed is forming, is changed to starch again 
by the amy loplast. 
Let us subject this theory of the translation of starch to a 
brief examination, There are two onl 
which starch can be converted into sugar, véz.: first. by the 
place at the ordinary temperature in the leaf of a plant and 
the extremely dilute weak vegeta- 
ble acids which the leaf contains. In the same way it must 
© Opportunity for the action of a ferment 
in the leaf is extremely limited.? Such action requires time 
and much more favorable conditions than can be found in the 
living leaf. In any case if sugar be formed from starch in 
either of the Ways indicated it could not be sucrose. 
In fact the reducing sugar which is found in plants is sel- 
dom starch sugar, 7. ¢. maltose or dextrose. This a pear 
to be a fact which the vegetable physiologists have entirely 
ignored. The Sugars of plants which reduce an alkaline 
copper solution are either derived from sucrose by inversion 
e 
c., and calls especial atten 
not be the original substance formed. 
“The ferment which acts on the starch has been studied by Brasse and Schimper (Bied. 
ase. 
T 
Centralbiatt, vol. 14, p. 169, yol, 15, pp. 310 and 473). It is‘callea amyl 
