Where is the theme man vs. nature illustrated in Lord of the Flies?quotes please !

Here at last
was the imagined but never fully realized place leaping into
life.

What Ralph in Chapter
One originally perceives to be an island paradise free from the confines of adults and
rules becomes a force against which the boys are in constant conflict.  For, from the
beginning, they must clamber through the creepers whenever they wish to explore the
island, negotiating the pink granite rock--"that token of preposterous time"--they
suffer from the relentless sun, plagued by the consumption of too many berries and no
meat; and they struggle to build and maintain
shelters. 

Certainly,the wild pigs become an element of
conflict as the boys initially try to kill them for food. But, later, the pigs become
the catalyst for Jack and the hunters' descent into savagery with the head of one pig
becoming the symbolic representation of Beelzebub and the evil that is inherent in the
heart of man.

In fact, as the narrative moves to its
conclusion, Nature becomes the dangerous foe of Ralph, Piggy and Simon.  For instance,
Simon is mistaken as a pig and bludgeoned to death in the hunters' frenetic ritual; the
sadistic Roger launches a pink granite rock upon Piggy, splitting his head and hurling
him into the omniverous sea.  And,of course, the fire, that formidable force of nature
that symbolizes power, becomes the penultimate foe when it is stolen by Jack and the
hunters who use it for their evil intent of flushing out Ralph by setting
fires:

Acres
of black and yellow rolled steadily toward the sea...The flames, as though they were a
kind of wild life, crept as a jaguar creeps on its belly toward a line of
birch....Beneath the capering oys a quarter of a mile square of forest was savage with
smoke and flame.

Only the
deus ex machina of the naval officer rescues the boys from the
devastation that the fire of nature threatens.  And, while the adversary of nature is
stalled with the rescue of an adult, the intrinisic adversary, the evil in man, yet
looms as "the trim cruiser in the distance" symbolizes the war in which adults are
engaged.