executed on the items 
 (for instance, if the index query is followed by computing a spatial predicate 
 between the query geometry and tree items, 
 the envelope intersection check is performed automatically.
 <p>
 This implementation does not require specifying the extent of the inserted
 items beforehand.  It will automatically expand to accomodate any extent
 of dataset.
 <p>
 This data structure is also known as an <i>MX-CIF quadtree</i>
 following the terminology of Samet and others.
<P>

<P>
<DL>