Giuseppe Castellano talks to author, critic, and children’s book historian, Leonard Marcus about his book, Pictured Worlds: Masterpieces of Children’s Book Art by 101 Essential Illustrators from Around the World; why Puffin’s tampering of Roald Dahl’s text opens the doors for publishers to rewrite—and re-illustrate—anything; why we should look to illustration’s history to understand its future; and more.