Wrap first letter and first sentence in span via jQuery

$('.myclass p').each(function(){
         // Split text at each period.
         var text = $(this).text().split('.');
         for( var i = 0; i < 1; i++ ) {
             // Wrap first letter in span.
             var first_letter = '<span class="first-letter">' + text[i].substr(0,1) + '</span>';
             // Wrap sentence in span.
             text[i] = '<span class="first-sentence">' + first_letter + text[i].substring(1, text[i].length) + '</span>';
         }
         $(this).html(text.join('.'));
      });