Final answer:
Roger doesn't hit Henry with rocks because he still fears societal consequences, which implies a loss of civility among the boys and foreshadows future violence.
Step-by-step explanation:
The reason Roger does not throw the rocks to hit Henry is because Roger fears the consequences of his actions. This is evident in the book 'Lord of the Flies' by William Golding, where it is implied that the unseen but powerful societal rules and norms are holding Roger back, despite the absence of adults. This behavior is suggestive of the boys' loss of civility as they become more savage on the island, and it foreshadows escalating violence among them as the plot develops.