28 HOW PLANTS GROW YEAR AFTER YEAR. 
they must have, in order to bear leaves; for leaves do not grow on roots. But 
what stem they make is so very short-jointed that it rises hardly any; so that 
the leaves seem to spring from the top of the root, 
and all spread out in a cluster close to the ground. 
As the plant grows, it merely sends out more and 
more branches of the root into the soil beneath, and 
adds more leaves to the cluster just above, close to the 
surface of the warm ground, and well exposed to the 
light and heat of the sun. Thus consisting of its two 
working organs only, — root and leaves, — the young 
biennial sets vigorously to work. The moisture and 
air which the leaves take in from the atmosphere, 
and all that the roots take from the soil, are digested ‘ 
or changed into vegetable matter by the foliage while 
exposed to sunshine; and all that is not wanted by 
the leaves themselves is generally carried down into 
the body of the root and stored up there for next 
year’s use. So the biennial root becomes large and 
heavy, being a storehouse of nourishing matter, which 
man and animals are glad to use for food. In it, in 
the form of starch, sugar, mucilage, and in other nourishing and savory products, 
the plant (expending nothing in flowers or in show) has laid up the avails of its 
whole summer’s work. For what purpose? This plainly appears when the next 
season’s growth begins. Then, fed by this great stock of nourishment, a stem 
shoots forth rapidly and strongly, divides into branches, bears flowers abundantly, 
and ripens seeds, almost wholly at the expense of the nourishment accumulated in 
the root, which is now light, empty, and dead; and so is the whole plant by the time 
the seeds are ripe. : 
71. By stopping the flowering, biennials can sometimes be made to live another 
year, or for many ‘years, or annuals may be made into bienhials. So a sort of 
biennial is made of wheat by sowing it in autumn, or even in the spring and keep- 
ing it fed down in summer. But here the nourishment is stored up in the leaves 
rather than in the roots. oe 
72. The Cabbage is a familiar and more striking example of a biennial in which 
the store of nourishment, instead of being deposited in the root, is kept in the 
57 
Radish. 
