Fig. 1.—Definite root-stock of the Iris.* 
THE VEGETABLE WORLD. 
——_ e———— 
ORGANOGRAPHY, OR THE STRUCTURE OF PLANTS. 
Commir a seed to the earth; plant, for example, a Haricot bean 
(Fig. 2) at the depth of two inches in moist vegetable soil, and if 
the temperature is between 15° and 20° R., the seed will not be slow 
to germinate, first swelling, and then bursting its outer skin, and 
* Fig. 1 is an example 0 of Rhizome, or underground stem or root-stock; a, the 
rootlets d consist of thick adventitious fibres; e, young root fibres from e, which 
have just begun to germinate. This kind of root is said to be de 
extent i is limited ; compound, because it pee of separate branches. 
