INDEX.
Abutilon, polymorphic flowers of, pp. [320], [323].
Acanthia lectularia, length of life of, [42].
Acineta, [151].
Acquired characters, meaning of, [169];
on supposed botanical proofs of transmission of, [390], [397].
Acridium migratorium, length of life of, [40].
Actinia mesembryanthemum, length of life of, [54].
Actinosphaerium, [117], [118].
Activity and length of life, [7], [8].
Adansonia, length of life of, [6].
Adler, on the formation of galls, [302].
After-effects, [403].
Aglia tau, deposition of eggs, [18];
length of life of, [18], [59].
Algae, immortality of unicellular, [25].
Amoeba, length of time of fission of, [8];
immortality of, [25];
Amphibia, polar bodies of, [340], [352].
Amphileptus meleagris, fission of, [148].
Amphorina coerulea, polar bodies of, [189].
Ancylus, length of life of, [56].
Andricus, length of life of summer generation, [50].
Anisotropism, [400].
Anlagen, [192].
Anodonta, length of life of, [56], [57].
Ants, duration of life of male and female, [18], [48], [50], [51], [52], [59], [156].
Aphilotrix, length of life of imago of, [50].
Aphis, length of life of, [41];
parthenogenesis of, [228], [289];
polar bodies of, [349].
Apis, see Bees.
fertilization of, [177];
nuclear division in ovum of, [188], [232], [360];
spermatogonia of, [220];
spermatogenesis of, [375].
Ascidians, length of life of, [57].
Atavism, [179].
Atrophy, of organs, [85], [86].
Auerbach, on fertilization, [355].
Bacteria, in dead Cockchafer, [46].
Baer, von, [194];
on the influence of maternal impressions on the offspring, [445].
Balanus, polar bodies of, [218].
Balbiani, on nuclear division, [187];
on pole-cells, [197];
on origin of ova, [222].
Balfour, on impregnation, [175];
on polar bodies, [214], [225], [339], [345], [353].
Bear, length of life of, [13].
Bees, length of larval life of, [15];
length of life of queen of, [18], [52], [156];
of drones, [18], [53]; of workers, [52], [59], [156];
activity of, [48];
death of male, [63], [120], [132];
loss of limbs in development of larva, [89];
nuptial flight of, [93];
development of eggs of, [226], [234], [285], [351].
Begonia, propagation of, [211].
Beneden, van, on fertilization in Ascaris, [177], [188], [355], [360];
on polar bodies, [214], [340], [345], [353];
on Polkörperchen, [216];
on spermatogonia in Ascaris, [220], [375];
on nuclear division, [231];
on sexual reproduction, [282].
Berthold, on male parthenogenesis, [247].
Bessels, on importance of fertilization, [235].
Beyerinck, on the formation of galls, [302].
Biorhiza, length of life of imago of, [50].
Birds, length of life of, [11], [36];
factors in duration of life of, [12].
Blackbird, length of life of, [6], [11], [36].
Blaps, length of life of imago of, [47], [48].
Blastogenic characters, [412].
Blochmann, on polar bodies, [349].
Blow-flies, length of larval life of, [15].
Boar, length of life of, [14].
Bombinator igneus, nature of ovum of, [125].
Bombus, [53].
Bombyces, flight of females impeded by eggs, [17];
habits of, [44].
Bonellia viridis, unequal length of life of male and female, [59].
Bonnet, on rudimentary tails in dogs, [428].
Born, on position of nucleus in ova, [177];
on double impregnation, [382].
Bosmina, parthogenesis of, [325].
Brooks, on heredity, [166], [326].
Brown-Séquard, experiments on guinea-pigs, [81], [310], [313].
Bulimus, length of life of, [55].
Buprestis splendens, length of life of, [47].
Burdach, on the influence of maternal impressions on the offspring, [444].
Bütschli, on polar bodies, [188], [214], [224], [340];
on sexual reproduction, [282];
on processes of fertilization, [355].
Butterflies, climatic varieties of, [99];
death of, [120].
Bythotrephes, spermatozoa of, [176];
summer eggs of, [239];
winter eggs of, [348].
Calberla, on impregnation in Petromyzon, [175].
Canary birds, length of life of, [36];
plumage of, [321].
Carabus auratus, length of life of imago of, [47].
Carnoy, on karyokinesis in ovum of Ascaris, [360], [368];
on spermatogenesis, [375].
Carp, length of life of, [6].
Cat, length of life of, [6].
Catallacta, [123].
Caterpillars, length of life of phytophagous, [15].
Cells, renewal of, [21];
nourishment of, [29];
death of, [59].
Cephalopods, length of life of, [56].
Cerambyx heros, length of life of imago of, [47].
Cetochilus, polar bodies of, [218].
Chermes, parthogenesis of, [294];
galls of, [401].
Cherry-tree, in Ceylon, [406].
Chrysomela varians, ovoviviparous development of, [48], [49].
Chydorus, parthenogenesis of, [325].
Cicada, length of life of, [41], [42].
Cienkowsky, on conjugation, [286].
Cionea intestinalis, length of life of, [57].
Circumcision, [434].
Cirrhipedes, complementary males of, [58].
Clausilia, length of life of, [55].
Cockchafer, length of larval life of, [16];
length of imaginal life of, [46].
Coleoptera, length of life of, [46].
Colpoda cucullus, fission of, [148].
Continuity of germ-plasm, [104].
Copepods, unequal length of life in the two sexes of parasitic, [58].
Coryne, origin of sexual bud, [205].
Cossus ligniperda, length of larval life of, [15].
Crayfish, length of life of, [6].
Cuckoo, length of life of, [11], [36].
Cyclas, length of life of, [56].
Cynipidae, length of life of, [49];
number of eggs of agamic, [50];
deposition of eggs of, [93];
number of males of, [293].
Cynips, amount of nuclear matter in egg of, [229];
parthenogenesis of, [274], [290], [293].
Cypris, [294].
Cytoplasm, [184].
Daphnidae, segmentation of the egg of, [73], [199];
loss of jaws in development of, [89];
winter eggs of, [121];
parthenogenesis of, [228], [325];
summer eggs of, [236], [239], [240];
polar bodies in parthenogenetic eggs of, [249], [345], [350].
Darwin, on constancy of number of individuals in successive generations, [12];
on atrophy of organs, [85], [90];
on cross fertilization, [309];
on effect of external influences, [391], [423].
Daucus, structure of root altered by cultivation, [414].
Death, origin of, [20], [21], [143];
relation to reproduction, [21], [120], [132], [154];
necessity of, [23], [24], [134], [159];
utility of, [24], [112], [135], [153];
an adaptation produced by natural selection, [24], [28], [60];
not universal, [25], [27], [111], [119];
by sudden shock, [63];
meaning of, [113];
definition of, [114];
of the soma, [154].
Degeneration of organs, see Atrophy.
Detmer, on transmission of acquired characters in plants, [390].
Development amongst Protozoa, [149].
Diatomaceae, fission of, [65].
Diptera, length of life of, [42];
pole cells of, [197], [206], [210], [216];
as fertilizers of flowers, [309].
Döderlein, on tailless cats, [390], [428], [430].
Dragon-flies, length of larval life of, [15];
length of life of imago, [17], [40].
Dryophanta, length of life of summer generation of, [49];
of winter generation, [50].
du Bois Reymond, on the transmission of acquired characters, [82], [390], [422].
Duration of life governed by needs of species, [9].
Düsing, on origin of sex, [239], [241].
Eagles, length of life of, [11], [37];
weight of, [14].
Echinodermata, origin of germ-cells, [202].
Echinus, polar bodies of, [351].
Ectocarpus, male parthenogenesis in, [247].
Eggs, number laid by various birds, [12], [37];
of insects, [17].
Eider-ducks, length of life of, [11].
Eimer, on the inheritance of mutilations, [426].
Eleodes grandis, and dentiper, length of life of imago of, [47].
Elephants, length of life of, [6];
gestation of, [7].
Encystment, relation to death of, [112], [115], [116], [120], [158];
of Rhizopoda, [121].
Entoniscidae, unequal length of life in male and female, [58].
Ephemeridae, length of life of imago of, [40], [156].
Epigenesis, theory of, [316].
Eristalis tenax, length of life of, [43].
Estheridae, [228].
Euglypha, identity of products of fission of, [26], [64], [65].
Eupithecia, length of life of, [45].
Falcons, length of life of, [11], [37].
Fiedler, on polar bodies in sponges, [217].
Flemming, on nuclear division, [187], [231], [359], [361].
Flourens, on length of life, [7].
Fol, on fusion of nuclei, [174], [189];
on origin of ova, [222];
on multiple impregnation, [236], [238], [382];
on polar bodies, [340], [351];
on process of fertilization, [355].
Formica sanguinea and fusca, length of life of, [51].
Fox, length of life of, [14].
Galton, on transfusion in Rabbits, [166];
on heredity, [172];
on twins, [380].
Gannets, numbers collected each year, [37].
Geotropism, [398].
Germ, meaning of, [148].
Germ-cells, [73];
predisposition of the, [84], [102];
fluctuations in, [102];
not continuous, [173].
Germ-plasm, [80], [191], [266], [341], [357], [371], [403];
continuity of, [104], [168], [173], [184];
definition of, [174].
Goliathus cacicus, length of life of imago of, [47].
Goose, length of life of the wild, [37].
Götte, on necessity of death, [112];
on rejuvenescence, [115], [124];
on death of Metazoa, [125].
Gregarines, [148], [149], [202].
Grobben, on polar bodies of Cetochilus, [218].
Gruber, on regeneration amongst Infusoria, [185].
Gryllotalpa, duration of life of, [39].
Gryllus campestris, duration of life of, [39].
Häckel, on reproduction, [72];
on Perigenesis of the Plastidule, [165];
on amphigonic reproduction, [272].
Hare, length of life of, [14].
Hartlaub, on origin of germ-cells in Obelia, [208].
Hawk-moths, length of life of imago, [17].
Helicidae, length of life of, [55], [56], [57].
Heliotropism, [399].
Hemiptera, length of life of, [41].
Hens, length of life of, [36].
Hensen, on sexual reproduction, [282], [286];
on difference between germ-plasm and histogenetic nucleoplasm, [343];
on heredity, [369].
defined, [72];
dependent on continuity of germ-plasm, [104], [168];
dependent on coalescence of nuclei, [178].
Hertwig, O., on fusion of nuclei, [174];
on the influence of gravity in segmentation, [177], [189];
on polar bodies, [340], [351];
on process of fertilization, [355].
Hesperornis, rudimentary wing of, [88].
Heterogeny, [325].
Heterogynis, [44].
Heteroplastides, [130], [131], [134], [139], [146], [153], [204].
Hildebrandt, on duration of life in plants, [32], [65];
on cross-fertilization, [309].
His, on heredity, [166], [390], [412];
on the transmission of mutilations, [423].
Hoek, on polar bodies in Balanus, [218].
Hoffman, on transmission of acquired characters, [407].
Homoplastides, [122], [139], [146], [202].
Horse, length of life of, [6], [7];
in the Falkland Islands, [99].
Humboldt’s Atur Parrot, [12].
Hunter, John, experiments in Anabiosis, [25].
Hyalineae, length of life of, [56].
Hybrids, [330].
Hydroids, origin of germ-cells of, [199], [206], [207], [211].
Hymenoptera, length of life of, [49].
Hypermetropia, [89].
Ichneumons, length of larval life of, [15];
length of life of imago of, [49].
Ichthyophthirius multifiliis, fission of, [148], [149].
Idioplasm, [174], [184], [192], [341];
not identical with nucleoplasm, [180];
relation to chromatin, [217];
two kinds of, [245];
various combinations of, [276].
Imago, length of life of, [16].
Immortality, injurious to species, [24];
of unicellular organisms, [25], [27], [33].
Infusoria, immortality of, [25], [72];
regeneration of lost parts in, [27], [185];
fission of, [64]; encystment of, [117].
Insects, duration of life amongst, [15];
duration of larval life of, [15];
normal death of, [22];
duration of imaginal life of, [38];
segmentation of egg of, [73];
deposition of eggs, [93];
origin of germ-cells of, [202];
polar bodies of, [218].
Instinct, [83];
used but once in a lifetime, [93].
Isotropism, of the ovum, [176].
Ivy, climbing shoots of, [393], [399].
Jäger, on heredity, [172], [206].
Jordan, on varieties, [269].
Julin, on spermatogenesis in Ascaris, [375].
Kallima, mimicry of, [280], [306].
Kant, on the transmission of mutilations, [423].
Keim, see Germ.
Kirchner, on development of Volvox, [204].
Kölliker, on nature of spermatozoa, [175];
on embryonic cells, [196].
Lagynus, fission of, [148].
Lamarck, on use and disuse, [83], [84], [303], [387], [391], [421].
Lamellibranchiata, length of life of, [55].
Larvae, length of life of, [15].
Lasius flavus, length of life of, [50];
L. niger, [51].
Lepidoptera, length of life of imagos of, [43], [156];
parthenogenesis among, [226], [352];
spermatogenesis in, [375].
Lepisma saccharina, length of life of, [40].
Leuckart, on relation of absorbing surface to size of animal, [7];
on development of Bees, [235];
on the influence of maternal impressions on the offspring, [445].
Limnadia Hermanni, [152].
Limnaeus, length of life of, [56].
Lion, length of life of, [13].
Lister, on chromatophores of blind Frogs, [301].
Locusta, length of life of imago of, [39].
Lotze, on activity in connection with longevity, [7].
Lucanus cervus, length of life of imago of, [47].
Lycaena violacea, length of life of imago of, [44].
Lynceinae, spermatazoa of, [176].
Macroglossa stellatarum, length of life of female of, [45].
Magosphaera planula, [75], [120], [122], [126], [147], [152];
figure of, [123].
Magpies, length of life of, [36].
Mammals, duration of life of, [38].
Maternal impressions, supposed influence on offspring, [444].
May-flies, length of larval life of, [15];
length of life of imago of, [16];
habitat of larvae of, [17];
shortening of life of, [19];
death of, [120].
Meldola, [395].
Melolontha vulgaris, see Cockchafer.
Mesozoa, [128].
Metazoa, [27], [28], [111], [145];
old age of, [157].
Metschnikoff, on pole-cells, [197].
Mimosa, ‘after effects’ in, [404].
Minot, on cyclical development, [199];
on polar bodies, [214], [225], [340], [345], [353].
Moina, winter eggs of, [118], [240];
segmentation of, [199];
polar bodies of, [218].
Molluscs, length of life of, [55];
determined by markings on shell, [14];
enemies of, [58].
Monoplastides, [115], [122], [125], [146], [159];
definition of, [120];
reproduction of, [149].
Mouse, length of life of, [6]; gestation of, [7].
Müller, F., on heredity of acquired characters, [320], [322].
Müller, H., on colours of flowers, [259];
on nectaries, [307].
Multicellular organisms, division of labour in, [27].
Musca domestica, length of life of, [43].
Musca vomitoria, polar bodies of, [353].
Myopia, [89].
on idioplasm, [174], [182], [190], [201], [340], [414];
on inherent tendency to vary, [256], [298];
on Alpine plants, [269];
on adaptation, [300];
on medium of heredity, [318], [355].
Najadae, length of life of, [56].
Natica heros, length of life of, [56].
Nautilus, persistence of, [300].
Nematodes, polar bodies of, [188];
nuclear division of ovum of, [234], [368].
Neuroptera, length of life of, [40].
Neuroterus, length of life of summer generation, [49];
of winter generation, [50].
Nigella, production of double flowers of, [408].
Nightingale, length of life of, [11], [36].
Nothnagel, on the cause of epilepsy, [314].
Nuclear plate, [187].
Nuclei, behaviour during fission, [118], [188];
connection of heredity with fusion of, [178];
influence of, [184];
influence in regeneration, [185];
nutrition of, [187].
Nucleoplasm, [179], [185], [191], [227];
histogenetic, [213];
ovogenetic, [213], [230], [243];
Nussbaum, on heredity, [172], [195], [206];
on regeneration amongst Infusoria, [185], [200].
Obelia, origin of germ-cells of, [208].
Obersteiner, on inheritance of epilepsy in guinea pigs, [311], [313].
Ophiostomum, karyokinesis in ovum of, [368].
Orgyia, [44].
Orth, on the transmission of acquired characters, [411].
figure of, [127];
degeneracy of, [130], [131], [141], [152].
Orthoptera, duration of life of, [39].
Ostracodes, parthenogenesis of, [294], [325];
polar bodies of, [350].
Otostoma Carteri, fission of, [148].
Palingenia, sub-imago stage of, [19], [40].
Paludinidae, length of life of, [56].
figure of, [203].
Pangenesis, theory of, [77], [165], [166], [193], [316], [327].
Panmixia, principle of, [90], [140], [291], [430].
Papaver, production of double flowers of, [408].
Paranucleus, [376];
of the sperm-cell, [221].
Parrots, length of life of, [36].
Parthenogenesis, the origin of, [225], [290], [323], [339];
not ancestral, [228];
of bees, [235];
partial, [238];
explanation of, [243];
male, [247];
of Cynips, [273];
Pasimachus, length of life of, [48].
Pemphigus terebinthi, length of life of, [41].
Petromyzon, impregnation of, [175], [247];
polar bodies of, [218].
Pfeffer, on chemical attraction of oosphere, [247].
Pfitzner, on nuclear division, [187].
Pflüger, on heredity, [70], [175], [355];
on the inheritance of acquired characters, [81], [390], [422];
on isotropism of the ovum, [176].
Phanerogams, fertilization of, [178], [247];
development of pollen grains of, [222].
Pheasant, the length of life of the golden, [36].
Philodina, polar bodies of, [350].
Phryganea grandis, [41].
Phylloxera vastatrix, length of life of, [41];
unequal length of life in two sexes of, [58];
parthenogenesis of, [294].
Pieris napi, length of life of, [44].
Pig, length of life of, [6].
Pigeon, length of life of, [36];
cross-breeding of, [332].
Pike, length of life of, [6].
Pisidium, length of life of, [56].
Planorbis, length of life of, [56].
Plants, duration of life of, [32], [65].
Polar bodies, [188], [218], [245];
the significance of, [212], [225], [339];
of Sponges, [217];
in parthenogenetic eggs, [249], [345], [383];
of Rabbit, [339];
number of, [346];
significance of second, [353], [362];
in plants, [377].
Pole-cells, of Diptera, [197].
Polistes gallica, ‘workers’ of, [53];
length of life of males and females, [54].
Pollen-grains, [222].
Polyphemus, spermatozoa of, [176];
summer eggs of, [239];
polar bodies of, [345].
Polyplastides, definition of, [120], [122], [125], [159];
development of, [152].
Polyzoa, length of life of, [57].
Poulton, on colours of caterpillars, [394];
on cats with supernumerary toes, [426].
Proteus, [87].
Protomyxa aurantiaca, [149].
Protozoa, development amongst, [150];
conjugation of, [287].
Psorosperms, [150].
Psychidae, length of life of, [16], [44], [45], [157];
deposition of eggs of, [18];
parthenogenesis of, [293].
Pulex irritans, length of life of, [42].
Pupa, length of life of, [55].
Rabbit, polar bodies of, [339].
Rauber, on heredity, [172].
Ravens, length of life of, [36].
Regeneration of lost parts, [65];
in Infusoria, [185].
Rejuvenescence, [112], [116], [124], [132], [153], [283].
Reproduction, original form of, [122];
effect of monogonic, [273], [275];
amphigonic, [279], [281], [287].
Reproductive cells, [27], [28], [111].
Rhodites rosae, parthenogenesis of, [325].
Richter, on inheritance of acquired characters, [438].
Robin, on pole-cells of Diptera, [197].
Rolph, on conjugation, [286].
Romanes, on correlation, [389].
Roth, on heredity, [166], [169].
Rotifera, unequal length of life in two sexes of, [58];
polar bodies of, [350].
Roule, on origin of ova, [222].
Roux, on the struggle of the parts in the organism, [87], [100];
on development in altered conditions, [177];
on forces controlling nuclear division, [231], [361];
on karyokinesis, [359].
Rudimentary organs, [88];
disappearance of, [291];
not found in parthenogenetic forms, [293].
Rumia Crataegata, [394].
Sachs, on reproduction in Mosses, [212];
on shoots of climbing Ivy, [393], [399].
Sagitta, segmentation of egg of, [74], [199].
Saperda carcharias, length of life of imago of, [47].
Sarcophaga carnaria, length of life of, [42].
Saturnia pyri, length of life of, [45];
S. carpini, cocoon of; [94].
Saturnidae, habits of, [44].
Saw-flies, ancestors of bees and wasps, [19];
length of life of imago of, [49], [59].
Schmidt, on malformations of the ear, [440].
Schneider, on instincts of perception, [92], [94].
Schultze, on polar bodies of Amphibia, [340], [352].
Scytosiphon, male parthenogenesis in, [247].
Sea-gulls’ eggs, [38].
Senility, [20], [21], [32], [157].
Sexes, unequal length of life in the two, [58].
Sheep, length of life of, [14].
Sida, spermatozoa of, [176];
absorption of ova in, [239].
Siebold, von, on development of Bees, [235].
Siphonophora, origin of germ-cells of, [202].
Sirenia, [261].
Sirex, length of larval life of, [15].
Smerinthus tiliae, length of life of imago of, [45];
ocellatus, [395].
Solenobia triquetrella, length of life of female of, [45];
death of parthenogenetic forms of, [64], [293].
Solidago, time of flowering changed, [415].
Soma, [122], [125], [130], [140], [144], [154], [155].
Somatic cells, [27], [28], [75], [111], [145], [158].
Somatogenic characters, [412].
Spathegaster, [49].
Spencer, Herbert, on relation of absorbing surface to size of animal, [7];
on influence of diminished nutrition, [241];
on correlation, [389].
Spirogyra, on cell-division in, [216].
Sponges, polar bodies of, [217].
Spontaneous generation, [34].
Sprengel, on colours in flowers, [308].
Squirrel, length of life of, [14].
Stahl, on protective structures in plants, [260].
Strasburger, on fertilization of Phanerogams, [178], [340], [355];
on cyto-idioplasm, [181];
on influence of nuclei, [184];
on identity of daughter nuclei, [187];
on nuclei of sexual-cells, [200], [215], [246];
on transmission of germ-plasm, [209];
on cell-division in Spirogyra, [216];
on development of pollen-grains, [222];
on parthenogenesis, [237];
on direction of growth of pollen-tube, [247];
on heredity, [354], [369], [369];
on polar bodies in plants, [377].
Strepsiptera, length of life of, [41];
unequal length of life in two sexes, [58], [59].
Succineae, length of life of, [55].
Swans, length of life of, [37].
Tagetes, production of double flowers of, [408].
Talents, transmission of, [95]; nature of, [96].
Termites, duration of life of, [18], [40].
Terns’ eggs, [38].
Thuja, dorso-ventral structure of shoots of, [391], [396].
Toad, length of life of, [6].
Transmission of acquired characters, [73], [80], [169], [267], [407], [411];
want of evidence of the, [81];
unnecessary for the theory of evolution, [83];
amongst Protozoa, [278];
supposed botanical proofs of, [387].
Trematodes, parasitic in Mollusca, [57], [131], [133].
Trichodinidae, conjugation of, [287].
Trichoplax adhaerens, [141].
Tridacna gigas, length of life of, [56].
Trinchese, on polar bodies, [189], [224].
Tropaeolum, two kinds of leaves of, [396].
Turkey, the length of life of, [36].
Twins, [380].
Unicellular organisms, immortality of, [25], [27].
Unio, length of life of, [56], [57].
Valaoritis, on origin of germ-cells, [195];
on physiological value of, [246].
Vanessa cardui, length of life of, [43];
V. prorsa, [44];
V. urticae, [44];
V. levana, deposition of eggs of, [94].
Variations, always present, [101].
Ventral canal cell, [223].
Vertebrata, late origin of reproductive cells in, [74].
Vespa, [53].
Viola calcarata, fertilization of, [310];
tricolor, [414].
Vitrinae, length of life of, [55].
Vorticellidae, conjugation of buds of, [287].
Vultures, length of life of, [11], [37].
Wallace, on constancy of number of individuals in successive generations, [12];
on production of death by natural selection, [23].
Wasps, duration of life of male and female, [18], [53];
loss of embryonic limbs in development of larva of, [89].
Westphal, on epilepsy in guinea-pigs, [314].
Whales, length of life of, [6]; adaptation in, [261].
White mice, experiments in the transmission of mutilations on, [431].
Will, on origin of ova, [222].
Wolff, on theory of epigenesis, [316].
Zacharias, on the inheritance of mutilations, [426].
THE END.
Transcriber's notes:
Footnotes were collected at the end of each essay and of the appendices for each essay.
On page [198] the formula (1/p) should probably be (1/pn).
Obvious typographical errors have been corrected. Any inconsistencies in spelling have been left.
“Notes” as used in this volume often means the same as footnotes. The Appendix to Essay I contains the "Notes" as used in that essay. In the footnotes to the Appendix to Essay I, one note refers to a note on another page which has been collected with all the other notes. The note referred to is indicated by a local note in braces.
In the footnotes for Essay VII this
“See ‘Nature,’ vol. 36, pp. 491-407.—E. B. P.”
was changed to
“See ‘Nature,’ vol. 36, pp. 491-507.—E. B. P.”
on supposition of a typo.