Paul Ehrlich

In his travels among those who had been relatively isolated from the culture of the European settlers he was struck by the difference in facial structure and bearing of the Native Americans compared to the people of European background he had grown up with

Image 12. Illustrations from Catlin’s Shut Your Mouth and Save Your Life contrasting natural sleep (left) and unnatural sleep (right)

And the most abominable, disgusting, and dangerous habit belonging to the human race . . . of sleeping with the mouth open