266 
Marsh Marigold, 160 
Mastodon, 94 
Mayweed, Scentless, 233 
Megalosaurus, 86 
Megatherium, 93 
Melicerta, 222 
Mesozoic Era, 46, 50, 51 
Mica, 23 
Micro-photography, 252 
Microscope, 248 
Milkmaid, 160 
Miller, Hugh, 66, 79 
Miocene Period, 52 
Misty Law, 26 
Mole, 203 
Mollusca, 70 
Molluscoidea, 69 
** Monkey-puzzles,”’ 102 
Monocotyledons, 133 
sub-classes of, 140 
Moonwort Fern, 177 
Moorhen, 159 
Moschatel, 198 
Mosses, 133, 178 
Mud, 15, 28 
Mud-fish, Australian, 83 
Mylodon, 93 
Myriapoda, 66 
Nature, co-operation in, 173 
Nature-study, how to begin, 8 
particular lines of, 11 
value of, 2 
Nautilus, Paper, 72 
Pearly, 72 
Nesting-boxes for birds, 240 
Nettle, Stinging, 151, 152 
Newts, 84, 158, 242 
Oak-apples, 179 
Oak, fossil remains of, 102 
Observation, practical, 11 
Oldhamia, 97 . 
Oligocene Period, 52 
Orchis, Butterfly, 192 
Coryanthes speciosa, 190 
Early Purple, 188 
Fragrant, 191 — 
Frog, 192 
Marsh, 191 
pollination of, 189 
Spotted, 191 
THE OPEN BOOK OF NATURE 
Ordovician Period, 48, 49 
Orthoceras, 76, '77 
Otter, 233 
Outcrop, 36, 169 
Oxen, fossil remains of, 92 
Ox-eye Daisy, 7 
Oyster Plant, 232 
Paleontology, 78 
Paleotherium, 92 
Paleozoic Era, 46, 48, 49 
Palms, fossil, 102 
Pansies, Wild, 187 
Pariasaurus, 51 
Parsley, Wild Beaked, 161 
Peat, 32, 33 
Penny Cress, 232 
Pennywort, Marsh, 199 
Perch, 83, 157 
Permian Period, 48, 49 
Persicaria, Pale-flowered, 144 
Spotted, 144 
Photographic cameras, 243 
Photography, micro-, 252 
Nature, 107, 116, 243-247 
Pike, 157 
Pimpernel, Bog, 209 
Scarlet, 209 
Yellow, 209 
Pines, fossil remains of, 102 
Pitch-stone, 25 
Plane, fossil remains of, 102 
Plant freaks, 213 
histories, 111 
pets, 112 
superstitions, 230 
Plants, carboniferous, 99 
collecting, 117 
drying, 117 
flowerless, 133 
fossil, 96 
cone-bearing, 102 
Latin names of, 146 
specific names of, 184 
Pleistocene Period, 52 
Plesiosaurus, 88 
Pliocene Period, 52 
Pluto, 24 
Pocket-lens, 248 
Polytrichum commune, 179 
“Poor Man’s Weather’ Glass,’’ 
209 
