Zoology Collected works 24 Animals 17 Physiology 17 Science 17 protoplasm 17 Mammals 14 enzymes 14 morphology 12 Botany 10 Ecology 10 India 10 Invertebrates 10 Vertebrates 10 Ornithology 9 Embryology 8 Insect 8 Morphology 8 Birds 7 Evolution 7 Insects 7 Metabolism 7 Biology 6 Entomology 6 Insecta 6 Protozoa 6 Animal behavior 5 Chemistry 5 Encyclopedias 5 Fishes 5