This circumstance occurs in chapter 1, shortly after all of the boys meet each other. Ralph seems to search his brain for a few moments until he comes to an adequate deduction. He commissions Jack to lead a special group of boys to hunt for their food. Ralph had desired to offer Jack something after noticing that Jack already had effective leadership skill and was actually embarrassed at not being chosen for their leader. Ralph's initial offer just had to do with leading the choir, but as the discussion continued, Ralph allowed Jack to make the decision as to their role, and this is what he chose: the role of providing food through hunting. It is almost as if Ralph feels sorry for Jack, or realizes the importance of being unified in the upcoming future.