title: Retrieving members from clusters (leafs)
body: <p>Once you build up clusters using <code>hclust</code>, then <code>cutree</code> to specify the down-clusters;
  how can you retrieve the members forming the different clusters? Suppose you created a simple hierarchical cluster, what command can retrieve the elements "separately" figuring in leafs of the group of clusters?</p>
  
  <p>I tried with <code>table()</code> but no way...</p>