Glowworms, 1, 10, 43, 77 _Gnathophausia_, 72 Goss, B. C., 143 Greene, C. W., 70 Guinchant, 37 H-ion concentration and luminescence, 92, 138, 155 Heat production and luminescence, 93 ff Heliotropism by animal light, 66. Heller, J. F., 1, 2, 16 _Heterocarpus_, 72 _Heteroteuthis_, 72 Hooke, R., 91 Hulme, N., 1 Hyde, Forsyth and Cady, 57, 63 Hydrogenase, 131 Hydroils, 10, 72 "Ignis fatuus," 15 Immune bodies, 104 Infection, with luminous bacteria, 13 Infra red rays in animal light, 48 ff Intensity of animal light, 63 Intracellular Luminescence, 68, 71 Interference colors, 14 Issatschenko, B., 66 Ives, H. E., 28, 44, 51 ff, 59, 61 Kemp, C., 78 Langley and Very, 43, 50 ff, 64 Lankester, E. R., 42 Lavoisier, 91 Lenard and Wolf, 37 _Ligia_, 13 _Limulus_, 129 Linnemann, E., 36 Lode, A., 65 Luciferase, 103 ff. Chap VI (properties); of _Pholas_, 114; of _Cypridina_, 123 ff Luciferesceine, 31, 110 Luciferin, 103 ff. Chap. VI (properties); of _Pholas_, 114; of _Cypridina_, 116 ff _Luciola_, 103, 125. Luminescence, 23 ff Luminosity, distribution in plant and animal kingdom, 3 to 12 Luminosity, false, 12 ff Luminous animals, habitat, 10 Luminous animals, uses of to man, 17 ff Luminous granules, 73, 75 Lyman rays, 21 Lyoluminescence, 35 MacCartney, J., 2, 3 Macfayden, A., 157 Macrozymases, 73 Man, luminosity of, 16 Mangold, E., 11, 72 Massart, J., 71 Mast, S. O., 69 Mayow, 91 McDermott, F. A., 31, 37, 45, 53 McKenney, R. B., 100 Medusæ or jelly fish, 2, 10, 72, 82 Methane, 15. Michaelis, G. A., 1 "Minimum radiation visually perceptible," 65, 144 Molisch, H., 45, 53, 61, 66, 102 Molluscs, 10, 72 _Monocentris_, 69, 104 Moore, B., 71 Muraoka, H., 61 Myriapods, 10, 35, 72 _Mytilus_, 116 Nadson, G., 66 _Nematocelis_, 72 _Noctiluca_, 2, 10, 71, 73, 82, 83, 89, 104 Noctilucin, 101 Nutting, P. G., 57, 59 _Nyctiphanes_, 72, 80 _Odontosyllis_, 83 _Orchestia_, 13 _Orya_, 35 Osborne and Wakeman, 121 _Ostræa_, 116 Otto, M., 37 Oxygen and luminescence, 1, 67, 85 ff, 147 ff Oxyluciferine, 108 ff, 127 ff, 158 Oxyluminescence, 36 ff, 111 ff Paint, luminous, 28, 29 Panceri, P., 45, 74 Pasteur, 42 Penetrating radiation in animal light, 61 ff _Pennatula_, 74, 103 Pennatulids or sea pens, 10, 72, 74, 82, 83, 89, 101, 103 _Peridineæ_, 10 Periodicity of luminescence, 71 Peron, F., 45 Peroxidases, 11, 126, 148 Peters, A. W., 11, 71 Pflüger, E., 1, 102 _Phengodes_, 41, 42 Phillips, A. H., 125 _Philoscia_, 13 Phipson, T. L., 101, 109, 110 _Pholas_, 10, 11, 72, 73, 74, 89, 101, 103, 105 ff, 114 ff, 131 Phosphine, 15 Phosphorescence, 24, 25 ff, 138, 143 Phosphoroscope, 26 Phosphor-photographic method, 52 Phosphorus and luminescence, 38, 39, 147 ff