Who accepted the responsibility for tending the fire and what further characteristics of Piggy are revealed in this chapter?

In Chapter 2 “Fire on the Mountain” in Lord of the Flies, Jack claims that his group will be responsible for the fire:  “’Ralph, I’ll split up the choir—my hunters, that is—into groups, and we’ll be responsible for keeping the fire going—‘” 

Throughout this chapter, Piggy reveals that he is a voice of reason among the boys on the island.  He questions Ralph’s leadership and asks why Ralph bends to the will of the other boys.  Piggy tells Ralph and the others that they must remain rational and work towards their survival on the island.  He berates the boys for acting like “a pack of kids” when they go out of control at the mention of starting a fire.  The chapter ends with Piggy noticing that one of the littluns is missing, but he is quickly overshadowed by the boys’ screams over a spark in the fire.