78 HOW CROPS GROW. 
Other sugars.—Other sugars or saccharoid bodies occurring in common 
or cultivated plants, but requiring no extended notice here, are the fo! 
lowing :— 
Mannite, Cy Hy, Oo, is abundant in the so-called manna of the apothe- 
cary, which exudes from the bark of several species of ash that grow in 
the Eastern Hemisphere, (Fraxinus ornus and rotundifolia.) It like- 
wise exists in the sap of our fruit trees, in edible mushrooms, and some- 
times is formed in the fermentation of sugar, (viscous fermentation.) 
It appears in minute colorless crystals, and has a sweetish taste. 
Quer'cile, Cy Hio Os, is the sweet principle of the acorn, from which it 
may be procured in colorless crystals, 
Pinite, Cs Hy Os, exudes from wounds in the bark of a Californian and 
Australian pine, (Pinus Lambertiana.) Separated from the resin that 
usually accompanies it, it forms a white crystalline mass of a very sweet 
taste. 
Mycose, Cyz Hoo On, is 2 sugar found in ergot of rye. It may be ob- 
tained in crystals, and is very sweet. 
Sugar of Milk, Lactose, Cy, Ho O1, + H,O, is the sweet principle of the 
milk of animals. It is largely prepared for commerce, in Switzerland, 
by evaporating whey, (milk from which casein and fat have been sepa- 
rated for makiny cheese.) Ina state of purity, it forms transparent, col- 
orless crystals, which crackle under the tecth, and are but slightly sweet 
to the taste. When dissolved to saturation in water, it forms a sweet 
but thin syrup. 
Mutual transformations of the members of the Cellulose 
Group.—One of the most remarkable facts in the history 
of this group of bodies is the facility with which its mem- 
bers undergo mutual conversion. Some of these changes 
have been already noticed, but we may appropriately re- 
view them here. 
a Transformations in the plant.—The machinery of the 
vegetable organism has the power to transform most, if 
not all, of these bodies into every other one, and we find 
nearly all of them in every individual of the higher order 
of plants in some one or other stage of its growth. 
In germination, the starch which is largely contained in 
seeds is converted into dextrin and glucose. It thereby 
acquires solubility,-and passes into the embryo to feed the 
young plant. Here it is again solidified as cellulose, starch, 
or other organic principle, yielding, in fact, the chief part 
of the materials for the structure of the seedling. 
