2 
THE VEGETATIVE ORGANS OF PLANTS. 251 
cut off just above the ground, underwent great and con- 
tinual variation from hour to hour (during rainy weather) 
when the soil was saturated with water and when the 
thermometer indicated a constant temperature. Hofmeister 
states that the formation of new roots and buds on the 
stump is accompanied by a sinking of the water in the 
pressure-gauge. 
Absorption of Nutriment from the Soil.—The food of 
the plant, so far as it is derived from the soil, enters it in 
a state of solution, and is absorbed with the water which is 
taken up by the force acting in the rootlets. The absorp- 
tion of the matters dissolved in water is in some degree 
independent of the absorption of the water itself, the plant 
having, to a certain extent, a selective power. 
3. The Root as a Magazine.—In fleshy roots, like 
those of the carrot, beet, and turnip, the absorption of 
nutriment from the soil takes place principally, if not en- 
tirely, by means of the slender rootlets which proceed 
abundantly from all parts of the main or tap-root, and es- 
pecially from its lower extremity ; while the fleshy portion 
serves as a2 magazine in which large quantities of pectose, 
sugar, etc., are stored up during the first year’s growth 
ot these, (in our latitude,) biennial plants, to supply the 
wants of the flowers and seed which are developed the 
second year. When one of these roots is put in the 
ground for a second year and produces seed, it is found to 
be quite exhausted of the nutritive matters which it pre- 
viously contained in so large quantity. 
In cultivation, the farmer not only greatly increases the 
size of these roots and the stores of organic nutritive ma- 
terials they contain, but by removing them from the 
ground in autumn, he employs to feed himself and his cat- 
tle the substances that nature primarily designed to nour- 
ish the grewth of flowers and seeds during another sum- 
mer. 
