How can I get the last descendant element using jQuery?
<p>OK, this should be super low hanging fruit.</p>

<p>I'm aware of <a href="http://api.jquery.com/last/" rel="nofollow">.last()</a> and yet for some reason my copy of jquery-min (version 1.4.2) is returning a <code>.last is not a function()</code> error when I call <code>$('form#demo td').last()</code> on the following markup:</p>

<pre><code>&lt;form id="demo"&gt;
  &lt;tr&gt;
    &lt;td&gt;1&lt;/td&gt;
    &lt;td&gt;2&lt;/td&gt;
    &lt;td class="action"&gt;3&lt;/td&gt;
  &lt;/tr&gt;
&lt;/form&gt;
</code></pre>

<p>even though a call to $('form#demo td') returns </p>

<pre><code>[td, td, td.action]
</code></pre>

<p>at the firebug console in Firefox 3.5.5.</p>

<p>What am I missing?</p>
