The lines on the cave ceilings remind me very much of what a large pot of finger paint looks like after children extract what they want to draw with. I could easily see my children (especially when younger) drawing on their own faces and bodies all kinds of designs using the colored clay.

Dan Woitulewicz
Detroit, Mich.

I appreciated conjectures by John Shea regarding manufacture of ancient stone tools by children rather than adults. As a modern-day flint knapper of 20 years, I have long suspected that many artifacts from ancient sites were made by beginners. Many of them look like the same junk I made my first 2 years of knapping.

Michael Williams
Columbia, Mo.