292 FIRST FORMS OF VEGETATION. 
absolutely dependent upon light for their very 
existence. Roses, tulips, sun-flowers, wait upon 
the beams of the sun, and live only in his smiles. 
They may be supplied with the requisite condi- 
\tions of heat, air, and moisture, but without light 
they will wither and die; or, if they do seem to 
grow, it is only a false, unnatural, and sickly 
growth, losing their substance instead of increas- 
ing it, and weighing less when dried than.the dry 
seed from which this amorphous growth proceeded. 
Light is not required for the germination of seeds ; 
but if the plant be suffered to grow up in darkness, 
it merely uses up the store of food contained in 
the seed, and when‘ that is exhausted its further 
growth is stopped. But to the influence of light 
the fungi are to a great extent insensible. They 
do not disturb themselves or deign to turn to- 
wards the light at all; they continue to shoot out 
perpendicularly, horizontally, or even reversed, 
just as the surface from whence they spring hap- 
pens to be directed. The Geranium growing in 
the cottage window, yearningly stretches out its 
tender leaves and blossoms to the smiling sun- 
shine without ; and the pea or potato sprouting in 
a cellar, which has but one north window, half- 
closed, spreads its cadaverous, blanched, and 
brittle shoots in the direction of that feeble flicker 
of light ; but the fungus points its stalk and its 
