VEGETABLE CYTOLOGY 
47 
and zymase of the same plant ferments these forming carbon dioxide 
and alcohol. 
Maltose is found in the germinating grains of barley and other 
cereals as a product of the action of the ferment diastase on starch. 
It reduces Fehling’s solution forming cuprous oxide but one-third 
less with equal weights. 
Trehalose or mycose is found in ergot, Boletus edulis, the Oriental 
Trehala and various other fungi. 
Melibiose is formed with fructose upon hydrolyzing the trisac- 
charose melitose which occurs in the molasses of sugar manufacture 
and in Australian manna. 
Touranose is produced upon hydrolyzing melizitose, a trisaccha- 
rose which occurs in Persian manna, and 
Agavose is found in the cell sap of the American Century Plant, 
Agave americana. 
2 . Starch. — Starch is a carbohydrate having the chemical formula 
of (C 6 Hio 0 5 )„ which is generally found as the first visible product 
of photosynthesis in most green plants. It is found in the chloro- 
plasts and chromatophores of green parts in the form of minute 
granules. This kind of starch is known as Assimilation Starch. 
Assimilation starch is dissolved during darkness within the chloro- 
plasts by the action of ferments and passes into solution as a glucose 
which is conveyed downward to those parts of the plant requiring 
food. In its descent some of it is stored up in medullary ray cells, 
and in various parts of the xylem, phloem, pith and cortex in the 
form of small grains. Considerable, however, is carried down to 
the underground parts such as rhizomes, tubers, corms, bulbs 
or roots where the leucoplasts store it in the form of larger-sized 
grains called Reserve Starch. This type of starch is generally 
characteristic for the plant in which it is found. It constitutes 
stored-up food for the plant during that period of the year when the 
vegetative processes are more or less dormant. 
Structure and Composition of Starch. — Starch grains vary in 
shape from spheroidal to oval to chonchoidal to polygonal. They are 
composed of layers of soluble carbohydrate material and probably 
other substances called u lamellce” separated from each other by a 
colloidal substance resembling a mucilage in its behavior toward 
