Nematophycus, [166]. Neuropteris, leaf impression, [6], [13]. — foliage of Medullosa, [122]. — with seed attached, [122], [85]. Nipa, [85]. Nodules, [15], [16], [9]. Nucleus, [47], [17].
Oliver, [187]. Osmunda, [125]. Ovule, word unsuitable for palaeozoic “seeds”, [77].
Palisade cells, [55], [25]. — tissue in leaves, [58]. — — — fossil leaf, [59], [34]. Palms, [85]. Parenchyma, [55], [24]. Petrifaction of cells, [4]. Petrifactions, [17]. — of forest débris, [18]. — treatment of specimens of, [184]. Phyllotheca, [173]. Plant, parts of, the same in living and fossil, [59]. — world, main families in, [44]. Platanus, [83]. Polypodiaceæ, [124]. Polystelic anatomy, [63], [72]. Populus, [83], [85]. Poroxyleæ, [88]. — description of group of, [96]. Poroxylon, anatomy of, [97], [116]. Primitive plants, [46]. Primofilices, [132]. Protococcoideæ, [47], [17]. Protodammara, [89]. Protoplasm, [47]. Protostele, [62], [70]. Protoxylem, [57], [31]. Psaronius, [129], [130]. — stem anatomy of, [131], [91]. Pteridophytes, development of secondary wood in fossil forms of, [72]. Pteridosperms, [44], [104], [114], [131]. — description of group, [114] et seq. — general distribution of in time, [177]. — summary of characters of, [123]. Pteris aurita, [62].
Quarries, [7], [1]. Quercus, [83], [85].
Race senility, [180]. Ranales, [103]. Renault, [2], [156], [187]. Reproductive organs, likeness between those of living and fossil plants, [67], [45], [46]. — — peculiar characters of some from the Palæozoic, [74]. — — simplicity of essential cells of, [52]. Rocks, persistence of mineral constituents, [36]. — fossils varying in according to the geological age, [37] et seq. Roof of coal seam, [24], [13], [25], [14]. Roots, likeness of structure in living and fossil, [60], [35].
Salix, [83]. Sambucus, [84]. Schizoneura, [173]. Sclerenchyma, [56], [26], [59], [34]. Scott, [2], [160], [187]. Secondary wood, development of in fossil members of families now lacking it, [72]. Seeds, series of types from spores to seeds, [75], [76], [52]-[58]. — position on the plant, [77], [78]. — Tertiary impressions of, [80], [81], [60]. Selaginella, [75], [133], [134]. — with four spores in a sporangium, [75], [53]. Sequoia, [86]. Seward, [187]. “Shade leaves”, [171]. Shale, [7], [1], [11], [24], [25], [36]. Sieve tubes, [57], [32]. Sigillaria, [142], [145]. Sigillaria, cast of leaf bases, [9], [2], [144], [102]. — description of, [144]. Silica, [17]. Silicified wood, [17], [80], [87]. Solms Laubach, [2], [187]. Specimens, treatment of, [184]. Sphenophyllales, [44], [153]. — description of, [153]. — general distribution in time, [177]. Sphenophyllum, [44], [153], [154], [160]. — cone of, [157], [116]. — fertile, [158]. — impression of foliage, [154], [112]. — plurifoliatum, [153]. — sporangia of, [158], [117]. — stem anatomy, [155], [113], [156], [114]. — stem in coal ball, [20]. — wood of, [156], [114], [115]. Sphenopteris, leaf impression, [11], [5]. — foliage of Pteridosperms, [115], [77]. Sporangium of ferns, [67], [45]. — of lycopods, [67], [46]. — of pteridophytes, [75], [52], [53], [54]. Spores, germinating, in fossil sporangia, [68], [47]. — peculiar structures among palæozoic examples of, [74]. — series of types from “spores” to “seeds”, [75], [76], [52]-[58]. — tetrads of, [75], [52], [53], [54]. Sporophyll, [75], [52], [53], [54]. Stangeria, [110]. Stele, modifications of, [62], [36]-[42]. Stems, external similarity in living and fossil, [60]. Sternbergia, cast of, [10], [4]. — pith cast of Cordaites, [93]. Stigmaria, [69], [142], [143], [144], [145]. — rootlet of, [143], [101]. Stomates, [54], [23]. — in fossil epidermis, [14], [8]. Stoneworts, [163]. Synclines, [23].
Taxeæ, [88], [90]. — comparison of fructification with that of Cordaiteæ, [95]. — description of, [92]. Taxeæ, fleshy seeds of, [89]. Taxodium, [86]. Taxus, [82]. Time, divisions of geological time, [34]. Tracheides for water storage, [56], [30]. Tree-ferns, [130]. Trigonocarpus, [11], [76], [82], [122], [84]. — once supposed to be a Monocotyledon, [82]. — probably the seed of Medullosa, [121]. Tubicaulis, [127], [89].
Unexplored world, [3]. Unicellular plants, [47], [17]. — — division of cells in, [47], [48], [18].
“Vascular bundles”, relation of to steles, [65], [42]. — tissue, [57], [31], [32], [33], [59]. — — continued growth of, [65], [43]. — — importance in plant anatomy, [61] et seq. Viburnum, [84], [85].
Watts, [187]. Westphalia, [19]. Wieland, [2], [102], [187]. Williamson, [2], [187]. Williamsonia, [104]. Wood, cells composing, [57], [31]. — centrifugal development of, [97], [65]. — centripetal development of, [97], [65]. — parenchyma, [57], [31]. — silicified, [17], [80], [87]. — solid rings of formed by cambium, [66], [44]. — vessels of Angiosperms, [58].