What does jack as about the conch?

In chapter 9: A View to a Death Jack holds a feast on the beach and invites boys to join his tribe. When Ralph tells him that he is still the chief and he has the conch Jack says, and I quote... "You haven't got it with you, "said Jack, sneering. "You left it behind. See, clever? And the conch doesn't count at this end of the island---"