Island Life

CHAPTER I. Introductory

INTRODUCTORY

Remarkable Contrasts in the Distribution of Animals--Britain and Japan--Australia and New Zealand--Bali and Lombok--Florida and Bahama Islands--Brazil and Africa--Borneo, Madagascar, and Celebes--Problems in Distribution to be found in every Country--Can be Solved only by the Combination of many distinct lines of inquiry, Biological and Physical--Islands offer the best Subjects for the Study of Distribution--Outline of the Subjects to be discussed in the Present Volume.

Pages 3-11

CHAPTER II. The Elementary Facts of Distribution.

THE ELEMENTARY FACTS OF DISTRIBUTION.

Importance of Locality as an Essential Character of Species--Areas of Distribution--Extent and Limitations of Specific Areas--Specific Range of Birds--Generic Areas--Separate and Overlapping Areas--The Species of Tits as illustrating Areas of Distribution--The Distribution of the Species of Jays--Discontinuous Generic Areas--Peculiarities of Generic and Family Distribution--General Features of Overlapping and Discontinuous Areas--Restricted Areas of Families--The Distribution of Orders

Pages 12-30

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CHAPTER III. Classification of the Facts of Distribution.--Zoological Regions

CLASSIFICATION OF THE FACTS OF DISTRIBUTION.--ZOOLOGICAL REGIONS

The Geographical Divisions of the Globe do not Correspond to Zoological Divisions--The Range of British Mammals as Indicating a Zoological Region--Range of East Asian and North African Mammals--The Range of British Birds--Range of East Asian Birds--The Limits of the Palaearctic Region--Characteristic Features of the Palaearctic Region--Definition and Characteristic Groups of the Ethiopian Region--Of the Oriental Region--Of the Australian Region--Of the Nearctic Region--Of the Neotropical Region--Comparison of Zoological Regions with the Geographical Divisions of the Globe

Pages 31-54

CHAPTER IV. Evolution As the Key to Distribution

EVOLUTION AS THE KEY TO DISTRIBUTION

Importance of the Doctrine of Evolution--The Origin of New Species--Variation in Animals--The amount of Variation in North American Birds--How New Species Arise from a Variable Species--Definition and Origin of Genera--Cause of the Extinction of Species--The Rise and Decay of Species and Genera--Discontinuous Specific Areas, why Rare--Discontinuity of the Area of Parus Palustris--Discontinuity of Emberiza Schoeniclus--The European and Japanese Jays--Supposed examples of Discontinuity among North American Birds--Distribution and Antiquity of Families--Discontinuity a Proof of Antiquity--Concluding remarks

Pages 55-71

CHAPTER V. The Powers of Dispersal of Animals and Plants

THE POWERS OF DISPERSAL OF ANIMALS AND PLANTS

Statement of the General Question of Dispersal--The Ocean as a Barrier to the Dispersal of Mammals--The Dispersal of Birds--The Dispersal of Reptiles--The Dispersal of Insects--The Dispersal of Land Mollusca--Great Antiquity of Land-shells--Causes Favouring the Abundance of Land-shells--The Dispersal of Plants--Special Adaptability of Seeds for Dispersal--Birds as Agents in the Dispersal of Seeds--Ocean Currents as Agents in Plant Dispersal--Dispersal along Mountain Chains--Antiquity of Plants as Effecting their Distribution

Pages 72-82

CHAPTER VI. Geographical and Geological Changes: the Permanence of Continents

GEOGRAPHICAL AND GEOLOGICAL CHANGES: THE PERMANENCE OF CONTINENTS

Changes of Land and Sea, their Nature and Extent--Shore-Deposits and Stratified Rocks--The Movements of Continents--Supposed Oceanic {xiii} Formations; the Origin of Chalk--Fresh-water and Shore-deposits as Proving the Permanence of Continents--Oceanic Islands as Indications of the Permanence of Continents and Oceans--General Stability of Continents with Constant Change of Form--Effect of Continental Changes on the Distribution of Animals--Changed Distribution Proved by the Extinct Animals of Different Epochs--Summary of Evidence for the General Permanence of Continents and Oceans.

Pages 83-105

CHAPTER VII

CHANGES OF CLIMATE WHICH HAVE INFLUENCED THE DISPERSAL OF ORGANISMS: THE GLACIAL EPOCH

Proofs of the Recent Occurrence of a Glacial Epoch--Moraines--Travelled Blocks--Glacial Deposits of Scotland: the "Till"--Inferences from the Glacial Phenomena of Scotland--Glacial Phenomena of North America--Effects of the Glacial Epoch on Animal Life--Warm and Cold Periods--Palaeontological Evidence of Alternate Cold and Warm Periods--Evidence of Interglacial Warm Periods on the Continent and in North America--Migrations and Extinctions of Organisms Caused by the Glacial Epoch

Pages 106-124

CHAPTER VIII. The Causes of Glacial Epochs

THE CAUSES OF GLACIAL EPOCHS

Various Suggested Causes--Astronomical Causes of Changes of Climate--Difference of Temperature Caused by Varying Distances of the Sun--Properties of Air and Water, Snow and Ice, in Relation to Climate--Effects of Snow on Climate--High Land and Great Moisture Essential to the Initiation of a Glacial Epoch--Perpetual Snow nowhere Exists on Lowlands--Conditions Determining the Presence or Absence of Perpetual Snow--Efficiency of Astronomical causes in Producing Glaciation--Action of Meteorological Causes in Intensifying Glaciation--Summary of Causes of Glaciation--Effect of Clouds and Fog in Cutting off the Sun's Heat--South Temperate America as Illustrating the Influence of Astronomical Causes on Climate--Geographical Changes how far a Cause of Glaciation--Land Acting as a Barrier to Ocean-currents--The Theory of Interglacial Periods and their Probable Character--Probable Effect of Winter in aphelion on the Climate of Britain--The Essential Principle of Climatal Change Restated--Probable Date of the Last Glacial Epoch--Changes of the Sea-level Dependent on Glaciation--The Planet Mars as Bearing on the Theory of Excentricity as a Cause of Glacial Epochs

Pages 125-168

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CHAPTER IX. Ancient Glacial Epochs, and Mild Climates in the Arctic Regions

ANCIENT GLACIAL EPOCHS, AND MILD CLIMATES IN THE ARCTIC REGIONS

Mr. Croll's Views on Ancient Glacial Epochs--Effects of Denudation in Destroying the Evidence of Remote Glacial Epochs--Rise of Sea-level Connected with Glacial Epochs a Cause of Further Denudation--What Evidence of Early Glacial Epochs may be Expected--Evidences of Ice-action During the Tertiary Period--The Weight of the Negative Evidence--Temperate Climates in the Arctic Regions--The Miocene Arctic Flora--Mild Arctic Climates of the Cretaceous Period--Stratigraphical Evidence of Long-continued Mild Arctic Conditions--The Causes of Mild Arctic Climates--Geographical Conditions Favouring Mild Northern Climates in Tertiary Times--The Indian Ocean as a Source of Heat in Tertiary Times--Condition of North America During the Tertiary Period--Effect of High Excentricity on Warm Polar Climates--Evidences as to Climate in the Secondary and Palaeozoic Epochs--Warm Arctic Climates in Early Secondary and Palaeozoic Times--Conclusions as to the Climates of Secondary and Tertiary Periods--General View of Geological Climates as Dependent on the Physical Features of the Earth's Surface--Estimate of the Comparative Effects of Geographical and Physical Causes in Producing Changes of Climate.

Pages 169-209

CHAPTER X

THE EARTH'S AGE, AND THE RATE OF DEVELOPMENT OF ANIMALS AND PLANTS

Various Estimates of Geological Time--Denudation and Deposition of Strata as a Measure of Time--How to Estimate the Thickness of the Sedimentary Rocks--How to Estimate the Average Rate of Deposition of the Sedimentary Rocks--The Rate of Geological Change Probably Greater in very Remote Times--Value of the Preceding Estimate of Geological Time--Organic Modification Dependent on Change of Conditions--Geographical Mutations as a Motive Power in Bringing about Organic Changes--Climatal Revolutions as an Agent in Producing Organic Changes--Present Condition of the Earth One of Exceptional Stability as Regards Climate--Date of Last Glacial Epoch and its Bearing on the Measurement of Geological Time--Concluding Remarks

Pages 210-237

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PART II. Insular Faunas and Floras

INSULAR FAUNAS AND FLORAS

CHAPTER XI

THE CLASSIFICATION OF ISLANDS

Importance of Islands in the Study of the Distribution of Organisms--Classification of Islands with Reference to Distribution--Continental Islands--Oceanic Islands

Pages 241-245

CHAPTER XII. Oceanic Islands:--the Azores and Bermuda

OCEANIC ISLANDS:--THE AZORES AND BERMUDA

The Azores, or Western Islands

Position and Physical Features--Chief Zoological Features of the Azores--Birds--Origin of the Azorean Bird-fauna--Insects of the Azores--Land-shells of the Azores--The Flora of the Azores--The Dispersal of Seeds--Birds as seed-carriers--Facilities for Dispersal of Azorean Plants--Important Deduction from the Peculiarities of the Azorean Fauna and Flora

Pages 246-262

Bermuda

Position and Physical Features--The Red Clay of Bermuda--Zoology of Bermuda--Birds of Bermuda--Comparison of the Bird-faunas of Bermuda and the Azores--Insects of Bermuda--Land Mollusca--Flora of Bermuda--Concluding Remarks on the Azores and Bermuda

Pages 263-274

CHAPTER XIII. The Galapagos Islands

THE GALAPAGOS ISLANDS

Position and Physical Features--Absence of Indigenous Mammalia and Amphibia--Reptiles--Birds--Insects and Land-shells--The Keeling Islands as Illustrating the Manner in which Oceanic Islands are Peopled--Flora of the Galapagos--Origin of the Flora of the Galapagos--Concluding remarks

Pages 273-291

CHAPTER XIV. St. Helena

ST. HELENA

Position and Physical Features of St. Helena--Change Effected by European Occupation--The Insects of St. Helena--Coleoptera--Peculiarities and Origin of the Coleoptera of St. Helena--Land-shells of St. Helena--Absence of Fresh-water Organisms--Native Vegetation of St. Helena--The Relations of the St. Helena Compositae--Concluding Remarks on St. Helena

Pages 292-309

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CHAPTER XV. The Sandwich Islands

THE SANDWICH ISLANDS

Position and Physical Features--Zoology of the Sandwich Islands--Birds--Reptiles--Land-shells--Insects--Vegetation of the Sandwich Islands--Peculiar Features of the Hawaiian Flora--Antiquity of the Hawaiian Fauna and Flora--Concluding Observations on the Fauna and Flora of the Sandwich Islands--General Remarks on Oceanic Islands

Pages 310-330

CHAPTER XVI. Continental Islands of Recent Origin: Great Britain

CONTINENTAL ISLANDS OF RECENT ORIGIN: GREAT BRITAIN

Characteristic Features of Recent Continental Islands--Recent Physical Changes of the British Isles--Proofs of Former Elevation--Submerged Forests--Buried River Channels--Time of Last Union with the Continent--Why Britain is Poor in Species--Peculiar British Birds---Fresh-water Fishes--Cause of Great Speciality in Fishes--Peculiar British Insects--Lepidoptera Confined to the British Isles--Peculiarities of the Isle of Man Lepidoptera--Coleoptera Confined to the British Isles--Trichoptera Peculiar to the British Isles--Land and Fresh-water Shells--Peculiarities of the British Flora--Peculiarities of the Irish Flora--Peculiar British Mosses and Hepaticae--Concluding Remarks on the Peculiarities of the British Fauna and Flora

Pages 331-372

CHAPTER XVII. Borneo and Java

BORNEO AND JAVA

Position and Physical Features of Borneo--Zoological Features of Borneo: Mammalia--Birds--The Affinities of the Borneo Fauna--Java, its Position and Physical Features--General Character of the Fauna of Java--Differences Between the Fauna of Java and that of the other Malay Islands--Special Relations of the Javan Fauna to that of the Asiatic Continent--Past Geographical Changes of Java and Borneo--The Philippine Islands--Concluding Remarks on the Malay Islands

Pages 373-390

CHAPTER XVIII. Japan and Formosa

JAPAN AND FORMOSA

Japan, its Position and Physical Features--Zoological Features of Japan--Mammalia--Birds--Birds Common to Great Britain and Japan--Birds Peculiar to Japan--Japan Birds Recurring in Distant Areas--Formosa--Physical Features of Formosa--Animal Life of Formosa--Mammalia--Land Birds Peculiar to Formosa--Formosan Birds Recurring in India or Malaya--Comparison of Faunas of Hainan, Formosa, and Japan--General Remarks on Recent Continental Islands

Pages 391-410

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CHAPTER XIX. Ancient Continental Islands: the Madagascar Group

ANCIENT CONTINENTAL ISLANDS: THE MADAGASCAR GROUP

Remarks on Ancient Continental Islands--Physical Features of Madagascar--Biological Features of Madagascar--Mammalia--Reptiles--Relation of Madagascar to Africa--Early History of Africa and Madagascar--Anomalies of Distribution and how to Explain Them--The Birds of Madagascar as Indicating a Supposed Lemurian Continent--Submerged Islands Between Madagascar and India--Concluding Remarks on "Lemuria"--The Mascarene Islands--The Comoro Islands--The Seychelles Archipelago--Birds of the Seychelles--Reptiles and Amphibia--Fresh-water Fishes--Land Shells--Mauritius, Bourbon, and Rodriguez--Birds--Extinct Birds and their Probable Origin--Reptiles--Flora of Madagascar and the Mascarene Islands--Curious Relations of Mascarene Plants--Endemic Genera of Mauritius and Seychelles--Fragmentary Character of the Mascarene Flora--Flora of Madagascar Allied to that of South Africa--Preponderance of Ferns in the Mascarene Flora--Concluding Remarks on the Madagascar Group

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