Science 525 Mathematics 225 Animals 211 Juvenile literature 157 Experiments 147 Plants 107 Dinosaurs 102 Comic books, strips, etc 101 Arithmetic 98 Astronomy 82 Miscellanea 82 Insects 72 Birds 71 Biology 56 Chemistry 54 History 51 Physics 51 Marine animals 50 Cosmology 49 Weather 49 Earth 48 Water 46 Natural history 41 Counting 38 SPM 38 Study and teaching (Elementary) 38 Endangered species 34 Light 34 Pictorial works 34 Study and teaching 34