THE STORAGE OF RESERVE MATERIALS 239 
mentioned, in solution in the cell-sap, but it can readily be 
made to crystallise out or to be precipitated in an amor- 
phous condition by the application of alcohol (fig. 113). 
We find many instances of the occurrence of various 
sugars as reserve materials. Cane-sugar is present in large 
quantities in the succulent parenchyma of the roots of the 
Beet and the Mangel-wurzel, and of the stems of the Sugar- 
cane; grape-sugar is found in the leaves of the bulbs of 
the Onion and allied plants; small quantities of raffinose 
are met with in the grains of barley and other cereals. 
\ 
INS 
Fig. 113.—SeuH@ro-orystats oF INULIN FROM THE ARTICHOKE. 
4, small crystals in the interior of cells treated with alcohol; x, large crystals 
extending through many cells. 
These are all present in solution in the cell-sap, as has 
previously been mentioned. — 
In many cases carbohydrate reserve materials are found 
to take the form of considerable thickening of the cell- 
walls. That these are really deposited in seeds with a 
view to subsequent utilisation is evident from a study of 
the endosperm of many palms, the cells of which consist of 
little else; the walls are so thick that the cavities are 
almost obliterated, and the small space that is left between 
the thickened walls contains apparently nothing but a 
small amount of protoplasm with which some amorphous 
protein matter is mixed. Even the unthickened cell-walls 
of most seeds must be looked upon as reserve food material, 
