White underwear, upon the laundry line.* 
Polka dot pajamas, oh my gosh they're mine! 
Oh don't you wish that you could have some too! 
That will happen only when your seat wears through. 

Four part round break (*) 

(Here's how I learned it as a scout in Ohio:) 

Orange striped socks, upon an outstretched line, 
Polka dot pajamas, oh my gosh they're mine! 
Oh don't you wish that you could wear them too! 
Sorry little friend they don't belong to you! 

(comment: pronounce "striped" in two syllables..."stri-ped")