UNORGANIZED CELL-CONTENTS. 
21 
( b ) CRYSTALLINE OR NON-COLLOIDAL. 
1. SUGARS. 
The sugars constitute a group of non-colloidal or 
crystalline principles of wide distribution. They occur 
in the cell sap, from which by evaporation or on treat- 
ment with alcohol they may be crystallized out. Quite 
a large number of distinct principles belonging to this 
class has been recognized, of which the following may 
be mentioned : 
Dextrose (grape-sugar or dextro-glucose) is found in 
sweet fruits, the nectaries of the flowers and stems and 
leaves of various plants. It crystallizes in needles and 
varies in amount from 1 to 2 per cent, (in peaches), to 30 
per cent, in certain varieties of grapes. It also occurs 
in combination with other principles, forming the 
glucosides. 
LsBVulose (fructose, fruit-sugar or laevo-glucose) is 
associated with dextrose, occuring in some instances 
even in larger quantities than the latter. 
Sucrose (saccharose or cane-sugar) is found rather 
widely distributed, as in the stems of corn, sorghum and 
the sugar-cane ; in roots, as the sugar-beet ; in the sap 
of certain trees, as sugar-maple and some of the palms ; 
in the nectaries and sap of certain flowers as fuchsia, 
caryophylllus and some of the cactacese ; in seeds, as 
almond and chestnut, and in various fruits, as figs, 
melons, apples, cherries. In some plants, as in sugar- 
cane, the yield is as high as 20 per cent. It crystal- 
lizes in monoclinic prisms or pyramids and forms 
insoluble compounds with calcium and strontium. 
Maltose is found in germinating cereals ; it forms 
colorless needle-shaped crystals resembling those of 
dextrose, and forms compounds with calcium, stron- 
tium, barium and acetic acid. 
Trehalose occurs in some fungi, as ergot and Agari- 
