I'm going to copy and paste them for you because they're far down on the web page but I'll also link to where I found them.
HUM---HUM---HUM---HUM
SOME---SOME---SOME---SOME
DUM---DUM---DUM---DUM
FUN---FUN---FUN---FUN
WELL THE SUM OF THE HUM IN A RUMBLEBUG'S
TUM
IS A BUMPITY RUM-TUM-TUM
AND THERE'S SOME THAT ARE GLUM WHEN THEY
COME TO THE DRUM
OF A RUMBLE-BUG'S RUM-TUM-TUM
BUT IT'S DUMB TO BE GLUM OR BE MUM OR BE
NUMB
IN THE PIT OF YOUR CRANIUM
'CAUSE YOU STRUM ON YOUR THUMB OR YOUR BUM
OR YOUR TUM
TO THE DRUM OF A RUMBLE-BUG'S HUM.
WELL THE SUM OF THE HUM IN A RUMBLEBUG'S
TUM
IS A BUMPITY RUM-TUM-TUM
AND THERE'S SOME THAT ARE GLUM WHEN THEY
COME TO THE DRUM
OF A RUMBLE-BUG'S RUM-TUM-TUM
BUT IT'S DUMB TO BE GLUM OR BE MUM OR BE
NUMB
IN THE PIT OF YOUR CRANIUM
'CAUSE YOU STRUM ON YOUR THUMB OR YOUR BUM
OR YOUR TUM
TO THE DRUM OF A RUMBLE-BUG'S HUM.
http://www.totse.com/en/ego/no_laughing_matter/frag-32.html