Identification Birds 108 Trees 83 Pictorial works 78 Classification 69 Fishes 49 Plants 38 more ... Insects 37 Fungi 36 Botany 35 Orchids 27 Timber 27 Wood 27 Bacteria 23 Handbooks, manuals, etc 20 Marine fishes 20 Diseases and pests 19 Weeds 19 Geographical distribution 18 Wild flowers 18 Grasses 17 Microbiology 16 Butterflies 15 Mammals 15 Mushrooms 15 Atlases 14 Diagnosis 14 Anatomy 13 Sharks 13 Technique 13 less ...