284 FIRST FORMS OF VEGETATION. 
to these curious organisms, is their origin. In- 
capable of deriving the elements of growth from 
the crude unorganized crust of the earth, they are 
parasitical upon organic bodies, and are sustained 
by animal and vegetable substances in a state of 
decomposition. That living and often nutritious 
objects should spring from festering masses of 
corruption and decay ; that plants, endowed with 
all the organs and capacities of life, should start 
into existence from the dead tree that crumbles 
into dust at the slightest touch, or draw their nour- 
ishment from dried and exhausted animal excre- 
tions, which have lain for months under the in- 
fluence of drenching rains and scorching sun- 
beams, is indeed a profound mystery of nature. 
No sooner does the majestic oak yield to the uni- 
versal law of death, than several minute existences, 
which had been previously bound up and hid 
within its own, reveal themselves, seize upon the 
body with their tiny fangs, fatten and revel upon 
its decaying tissues, and in a short space of time 
reduce the patriarch and pride of the forest, which 
had braved the storms of a thousand years, into 
a hideous mass of touchwood, or into a heap of 
black dust. How strikingly do these plants illus- 
trate the great fact, that in nature nothing perishes; 
that in the wonderful metamorphoses continually 
going on in the universe there is change, but not 
