Contents. 
IX 
Page 
Variation 53 
The five phases of Variation in birds, 53 — 1. Individual variation: its universality, 53 
— Eange of individual variation, 54 — Psychological differences of individuals, 54 — 
Monstrosities, 55 — Albinism, melanism, etc., 55 — Dichromatism, 55 — Modifications due 
to foreign violence, food, etc., 56 — 2. Geographical variation: New species arising 
under geographical isolation, 57 — Increase of size in the Sangi and Talaut Islands, 58, 59 
~ Decrease in Snla, 60 — Similar geographical variations of coloration, 61 — 3. Seasonal 
changes: almost unknown in the tropics, 62 — The moult, 63 • — Change of coloration 
without a moult, 63 — 4. Sexual differences: classification thereof, 64 — The psycho- 
logical differences of the sexes, 65 — Theories in explanation of the development of secondary 
sexual characters, 66—69 — 5. Changes depending upon Age: classification thereof, 70 
— Ancestral characters, 71 — their value in questions of descent and of geographical distri- 
bution, 72 — Phylogenetic value of the tips of feathers, 73 — Hereditary effects of shelter 
and exposure: the tail-feathers of Pt-ionitunis, 73 — of Merops, 76 — other cases, 77 — 
Effects of light, 78 — 79. 
Geographical Distribution 80 
The contrast between the Oriental and Australasian faunas and floras, 80 — Status of geolo- 
gical knowledge of the East Indian Archipelago, 80 — Wallace’s line: Wallace’s opinions 
thereon, 81 — Blyth, 82 — Pijnappel, 82 — v. Pelzeln, 82 - — Veth, 82 — Allen on the 
mammals 82 — Semper, 83 — Krummel on the sea-depths, 83 — Martin, 85, 85 — 
Wichmann, 84 — Drude, 84 — Heilprin, 84 — Marshall, 84 — Kan, 84 — Eeichenow, 84 
— Schuiling, 84 — Jentink on the mammals, 84 — • Eeclus, 85 — v. Martens on the 
land-shells, 85, 87, 88 — Warburg, 85 — Trouessart, 85 — P. L. Sclater, 85 — Flower and 
Lydekker, 86 — van der Lith, 86 — Haeckel, 86 — Haacke, 86 — Newton, 86 — Sharpe, 88 
— Guillemard, 86 — Weber on the fresh-water fishes, 87 — Beddard, 87 — Lydekker, 87 
— Hedley on land-shells, 87 — Supan, 88 — Kiikenthal, 88 — W. L. Sclater on the 
mammals 88, — Niermeyer, 88 — The conflict of opinions, 88 — Table of the Geogra- 
phical Distribution of the Birds of the Celebesian Area, 90 — 111 — Peculiar 
genera and species of Celebes, 112 — Table showing the estimated value of the affinities of 
the peculiar species of Celebes, 115 — 117 — Summary of the various components of the avifauna 
of Celebes, 118 — List of the Birds of the Sangi Islands, 120 — of the Talaut Islands, 121 
— Affinities of the peculiar species of Sangi and Talaut, 122 — List of the Birds of the 
Peling Group, 123 — of the Sula Islands, 124 — Evidences of the former union of Peling 
and Sula, 125 — List of the Birds of Saleyer Island, 125 — of the Djampea Group, 126 
— Affinities of the peculiar species of Saleyer and Djampea, 126 — List of the Birds of 
Togian Island, 126 — Peculiar species and subspecies of Celebes (Mainland], 127 — Differences 
of the birds of the North and South Peninsulas, 128 — Eesults, 130. 
Meyer & Wigleswortli Birds of Celebes (May 20 * 1 *^ 1898). 
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