1887. | BOTANICAL GAZETTE. 59 
the formation of other bodies or for working it into living tis- 
sues is by thus getting it into protoplasm.) On the other hand 
the content of sucrose in sorghum is sensibly the same in all 
parts of the cane, being just as great at the top near the place 
of most rapid starch storage, as it is near the base. It is not 
strange, therefore, if it be true that the production of sucrose 
is only the expression of the exuberant vitality of the leaf of 
the sorghum, that the greatest variations should be met with 
the content of sucrose. These variations are not confined to 
different varieties or to different fields but are found in the 
same variety in different canes growing in the same hill, and 
which, therefore, have been subjected to precisely the same 
conditions of culture and weather. 
n ten successive analyses of sugar beets made two years 
ago, I found no greater variation than one per cent. in sucrose. 
he same was true of ten successive analyses of sugar-canes 
I made last month, November, 1886. On the other hand, 
any ten successive analyses of sorghum canes, made last 
October, will show a variation of six per cent. 
_ I have not the time here to cite all the instances I have 
noticed which illustrate the principles set forth above. They 
number hundreds. Without a record of these analyses, how- 
ever, the fact clearly appears that the chief cause of variation 
is found in the accidental or adventitious nature of the form- 
ation of the sucrose—in other words, its independence of the 
life history of the plant. When, however, the sucrose has 
once been formed, as ina mature cane, it is subject to sudden 
variations. Sudden changes in the weather, severe frosts, 
followed by warm weather, or simply standing dead ripe, 
often cause a rapid disappearance of the sucrose. It is first 
converted into invert sugar and this quickly disappears by 
fermentation. 
hen the canes have been cut also, if they be expressed at 
a temperature of a warm September day, the sucrose is rap- 
idly inverted. This inversion is not due to the action of the 
acids which the sap contains, but is produced by a special 
ferment, probably czvertin, or some similar substance.‘ oe 
ese variations in the content of sucrose, are, as I inti- 
mated at the beginning, the chief obstacles now in the way 
of the successful introduction of a sorghum sugar industry 
into this country. The last one is easily avoided by promptly 
working the cane as soon as it is cut. The first one can 
*Ducloux, Compt. rend, 103, p. 881, has shown that sunlight is capable of inverting & 
Solution of sucrose, 
