Educators say children need more familiar images Like many of his third-grade classmates, Mario Cortez-Pacheco likes reading the “Magic Tree House” series, about a brother and a sister who take adventurous trips back in time. He also loves the popular “Diary of a Wimpy Kid” graphic novels. At Bayard Taylor Elementary in Philadelphia, three-quarters of the students are Hispanic. But Mario, 8, has noticed something about these and many of the other books he encounters in his classroom at Bayard Taylor Elementary here: most of the main characters are white. “I see a lot of people that don’t have a lot of color,” he said. Hispanic students now make up nearly a quarter of the nation’s public school enrollment, according to an analysis of census data by the Pew Hispanic Center, and are the fastest-growing segment of the school population. Yet nonwhite Latino children seldom see themselves in books written …