When this cartoon first ran, a couple of readers wrote to inform me it's a misconception that a frog will boil to death, unaware, in water that is slowly heated. I'm not surprised; frogs can't be that stupid. In my defense, I did say, "the proverbial frog." Besides, they were missing the larger point of the cartoon, which remains one of my favorites.
 
 

 
"Click on the cartoon"