Grabbing first child <span> from the parent element using jQuery

What jQuery function would I use to grab the closest to the top of 开发者_开发技巧a div <span> and also the very last in the list as well?

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The HTML

<div id="spans">
    <span></span>
    <span></span>
    <span></span>
    <span></span>
    <span></span>
</div>

the jQuery:

$('#spans span:first,#spans span:last');

Your question requires more explanation but this is a punt at what your looking for.