In Lord of the Flies, how does the conch represent justice?

The conch shell really represents control and a governing
hand.  However, it also represents justice because whoever holds the conch is to have
the right to speak.  So this "justice" only lasts a few chapters.  After growing tired
of all of the rules, Jack and his group don't care about following the conch any more. 
They speak when they want to--and feel that only those who SHOULD speak will speak.  So
at this point, justice is gone.  There is no equality and only a handful of boys are
following the rules.