Ecology, 1, 2, 18, 19, 20, 60 and economic problems, 114 and geology, 22 art of, 33 associational, 24 fish of Walnut Lake, 147 history, 133, 138 point of view, 8 relation to economic entomology, 21 relation to geology and paleontology, 10 relation to man, 10, 11 relation to physiology, 8 relation to sociology, 10 relation to teaching, 13, 14 research methods, 88 Economic entomology, 29, 71, 74, 75 bibliography, 74, 75 bibliography of American, 71, 75 relation to ecology, 21 Economic problems and ecology, 114 Economic value, of birds, 126 of _Pecten irradians_, 108 Economic zoölogist, 29 Economic zoölogy, 29 Educational value of ecological ideas, 146 Effects, similar, of diverse stimuli, 98 Egg-laying crawfish, 108 Egg-laying sites, Orthoptera, 137 Eggs, collecting birds’, 58 of birds of North America, 109 Elbe River, fauna of lower, 138 Emergency surgery, 65 Emotion in pigeons, 110 Enchytræidæ, 58 Encroachments of civilization, 26 Enemies, protection of animals from, 125 English in science, better, 67 English sparrow, 28, 117 psychology, 117 Entomological Commission, of U. S., report on cotton and boll worm, 77 of U. S., report on Rocky Mountain locust, 76 of U. S., report on western cricket, 77 Entomological ecology of Indian corn plant, 132 Entomological work of Townend Glover, 73 Entomological writings of A. S. Packard, 74 Entomologists’ reports, Illinois, index, 74 Missouri, 77 New York, 74 Entomology, bibliography of American economic, 71, 75 catalogue of publications on, 71 economic, _see_ Economic entomology Entomophilous flora, ecological relations to anthophilous insect fauna, 142 Environment, 5 and the animal, adjustment between, 122 describing, 45 development, 45, 46 effect on development of mollusks, 100 effect on insects, 96, 97 effect on limpet, 101 effect on snails, 100 fish, 64, 118 fitness, 85 great changes, 26 gross evolution, 86 making to order, 33 natural, and behavior, 110 natural or normal, 34 orderly sequence, 79 original conditions, 25, 26 parasites, 126 sequence of changes, 104 _Epeira_, habits, instincts, 117 Ephemeridæ, 76 _Epinomia triangulifera_ Vachal, bee community, 139 Equilibrium, relative, 30, 31 Ethological maladjustments of ants, 126 Ethological observations on an ant, 120 Ethological study, comparative, of spiders, 138 Ethology, 18, 19, 21, 59 and mutation theory, 22 ants, comparative, 149 diagram of subdivisions, 133 history, 133 subdivisions, in diagrams, 133 Europe, cave fauna, 144 plant galls, 143 Evaporating power of air, vegetational control of, relative, 90