Pores giving off water vapour, 31 Pores in stems, 96 Potassium iodide, 11 Potassium nitrate, 15 Potato, starch in, 11 Potato, underground stem of, 61, ~47~ Primrose flower, 80, ~72~, 84, ~79~, 120, ~120~ Prothallium, 135, ~129~, 139 R Receptacle of flower, 82, ~76~, ~78~ Reeds, 162, ~144~ Rhizome, 61, ~46~, 161, ~143~ Rice, starch in, 11 Roots, adventitious, 56, ~40~, 57, ~41~ Roots, entrance of water into, 33, ~21~, ~22~ Roots, forms of, 54 Root-hairs, 13, ~8~, 15, ~9~ Root pressure, 34 Roots of seedlings, 9 Roots, stilt-, 57, ~42~ Roots, storage in, 55, ~38~, 56, ~39~ Roots, uses of, 53 Rose, flowers of, 79, ~70~, ~71~, 118, ~116~ Rose-leaf, 65, ~51~ Rose-seedling, 66, ~54~ Runners of strawberries, 63 Rushes, 162, ~144~ S Salts, 14, 17, 27 Sandgrass (~see~ Marram), 102, ~100~, 165, ~145~ Sea, 174 Sea holly, 168, ~147~ Seaweeds, 143, ~134~, ~135~, 173 Seaweeds, colour in, 176 Section of pond, 192, ~154~ Section of stems, 93, ~92~ Seedlings, bean, 10, ~6~, 40, ~28~, ~29~ Seedlings, grass, 35, ~23~ Seedlings, maize, 10, ~5~, 13, ~8~ Seedlings, pine, 129, ~126~ Seedlings, rose, 66, ~54~ Seeds, 86, 125 Seeds, bean, 8, ~3~, 9, ~4~, 10, ~6~, 91, ~89~ Seeds, dodder, 111 Seeds, larch, 128, ~124~ Seeds, maize, 9, ~5~, 91, ~90~ Seeds, mistletoe, 112 Seeds, pine, 129, ~125~ Sensitive Plant, 47, ~33~, ~34~, ~35~ Sepals, 78, ~69~ Shore, 165, ~Pl. VI.~, 176, ~150~ Skin of leaf, 95 Skin of seed, 9, ~3~ Sleep of plants, 46, ~32~ Sodium chloride, 15 Solomon’s Seal, 61, ~46~ Speedwell, 80, ~73~ Spines of cactus, 62, 99, ~97~ Spines of gorse, 102, ~99~ Spores, 135, 139, 140, 142 Stamens, 80, ~72~, ~73~, 81, ~74~ Starch, 11, 12, 21, 23 Starch formed in leaves by sunlight, 24 Starch stained by iodine, 11 Starch stored underground, 26 Stellaria, 59, ~45~ Stems, 58 Stems bending again to earth, 63, ~49~ Stems, branching of, 59 Stems, breathing pores in, 94, 96, ~96~ Stems, fleshy, 62, ~48~ Stems, sections of, 93, ~92~ Stems, twining, 106, ~102~, 110, ~106~ Stems, underground, 61, ~46~, ~47~ Stigma, 83 Stipules, 64, ~50~, ~51~ Stone-crop, 102, ~98~ Strawberry fruit, 90, ~88~ Strawberry runners, 63 Sundew, 114, ~110~, 115, ~111~ Sunflower, 1, 2 Sunflower stem, 94, ~93~, ~94~ Sunlight, oxygen given off in, 21, ~13~ Sunlight helps to form starch in leaves, 25 Sweet pea flower, 86, ~80~ Sweet pea fruit, 87, ~81~ Sweet pea leaf and tendrils, 45, ~31~, 70, ~61~ Sweet pea seed, 87, ~81~ Sycamore, buds of, 75, ~66~ T Tendrils, movement of, 45, ~31~ Tendrils part of leaf, 70, 71 Tendrils assist climbing, 107, ~104~, 108, ~105~ Tissues, 93 Toadflax, 148, ~136~ Toadstool, 142, ~133~ Transpiration, 31 Traveller’s Joy, 147 Tree ferns, 133, ~Pl. III.~ Tubers, 61, ~47~