'In my youth,' Father William replied to his son,
    'I feared it might injure the brain;
   But, now that I'm perfectly sure I have none,
    Why, I do it again and again.'

   'You are old,' said the youth, 'as I mentioned before,
    And have grown most uncommonly fat;
   Yet you turned a back-somersault in at the door--
    Pray, what is the reason of that?'