NON-PROTOPLASMIC CELL CONTENTS 75 
slide; in this place the section and put on the cover slip. If fructose is present 
cuprous oxide crystals will at once be formed without warming. If grape sugar is 
also present, a gentle warming will produce another crop of reddish-yellow crystals. 
If dextrin be present, continued heating will still further augment the number of 
crystals. Cane sugar and mannite, on the other hand, will respond negatively to 
this test. 
The Drisaccuaroses, having the chemical formula of 
Ci2H22011, include _ sucrose, maltose, trehalose, melibiose, 
touranose and agavose. Of these e SUCROSE i is the most important. 
It is found in the stems of sugar cane, sorghum, corn and Mexican 
grass; in many fleshy roots notably the sugar beet; in the sap of 
the sugar maple and various palms; in various fruits, as apples, 
cherries, figs, etc., in the nectaries of certain flowers; in honey; 
and in a number of seeds. It crystallizes in monoclinic prisms 
or pyramids. 
When sections of plant parts containing cane sugar are placed for a few seconds 
in a saturated solution of copper sulphate, then quickly rinsed in water, transferred 
to a solution of 1 part KOH in 1 part of water, and heated to boiling, the cells 
containing the sugar take on a sky-blue color. 
Invertase, an enzyme of the yeast, reduces cane_sugar to dex- 
trose and levulose and zymase, another enzyme of the same plant, 
ferments these forming carbon dioxide and alcohol. 
MALTOSE_ is found in the germinating grains c of barley and 
other cereals as a product of the action of the ferment diastase on 
starch. Itreduces Fehling’s solution, forming cuprous oxide, but | 
one-third less with equal weights. 
TREHALOSE or mucose is found in ergot, Boletus edulis, the 
Oriental Trehala and various other fungi. 
Meurpiose is formed with fructose upon hydrolyzing the 
trisaccharose melitose which occurs in the molasses of sugar 
manufacture and in Australian manna. 
Touranose is produced upon hydrolyzing melizitose, a 
trisaccharose which occurs in Persian manna. 
Acavose is found in the cell sap of the American Century 
Plant, Agave americana. 
2. Srarcu.—Starch is a carbohydrate having the chemical 
formula of (CoH1005)n_¥ which is generally found as the first 
visible product of ‘photosynthesis in most green plants. 2 
