Blood

[Seafood]

A teacher was giving a lesson on the circulation of the blood.

Trying to make the matter clearer, she said,

'Now, class, if I stood on my head, the blood, as you know,

would run into it, and I would turn red in the face.'

'Yes,' the class said.

'Then why is it that while I am standing upright in the ordinary

position the blood doesn't run into my feet?'

Little Johnny shouted, 'Cause your feet ain't empty.'