The biggest immediate contrast drawn between the two boys is how Golding portrays Piggy's visible struggle with the elements. As the novel opens, Piggy fights his way through the thick jungle foliage:
"I can't hardly move with all these creeper things" (7).
Piggy is out of breath, scratched up, and has an upset stomach from eating the native fruit from the trees. From Golding's characterization, it almost seems as if the island violently opposes Piggy and rejects his very presence. Piggy does not belong amidst the wilderness of the island setting.
Ralph, however, seems to fit right in:
"The fair boy stopped and jerked his stocking with an automatic gesture that made the jungle seem for a moment like the Home Counties" (7).
At the same time that Piggy has so much difficulty, Ralph already seems as though he is back home in England. He and the island immediately take to each other. Ralph's healthy athleticism allows him to adapt and explore the island with ease, whereas Piggy's over-weight physique and asthma makes traversing the jungle extremely difficult for him.