Li 



>ttL 



I 



CONTENTS OF THE SECOND VOLUME. 



xiu 



4« 



• *X 



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H 



<U(u^ 





The Qn^ 



' " ' Origiij of ,C: 

 *« Flora of Ad, 



I^^TIOX THWEDii 



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ious and X.i. 



some r . 



ag-Iofri Clurae;c:i: 



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articular Pan^ of ^ 



Jtered-ilaue-Ca^ 

 5c;..?-0bedieDce:. 



- a Xatural h^ 

 in their Capac? 



Original ^^ 



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of spec 



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1 AfiJ 



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y- 



Corr*"' 



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 i SP^^'.J of * 



ret^iDg 



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.tif' 







CHAP TEE XXXVIII. 



ON THE GEOGRAPHICAL DISTRIBUTION OF SPECIES. 



Geographical Distribution of Animals — BuiFon on Specific Distinctness of Quad- 

 rupeds of the Old and New. Worlds — Doctrine of * Natural Barriers ' — Australian 

 Marsupials — Geographical Kelation of Extinct Fossil Forms to their nearest 

 allied Living Genera and Species — Geographical Provinces of Birds according to 

 Dr. Selater — Their Applicability to Animals and Plants generally — Neotropical 

 Eegion — Nearctic— Palcearctic — Ethiopian — Indian — Australian — Wallace on 

 the Limits of the Lidian and Australian Eegions in the Malay Archi- 



F 



pelago . 



PAGE 329 



CHAPTER XXXIX. 



ON THE MIGRATION AND DIFFUSION OF TERRESTRIAL ANIMALS. 



Migration of 'Quadrupeds — Migratory Instincts — -Drifting of Animals on Ice-Floes 

 Migration of Birds — Migration of Eeptiles — Involuntary Agency of Man in 



354 



the Dispersion of Animals 



CHAPTER XL. 



ON THE GEOGRAPHICAL DISTRIBUTION AND MIGRATION OF SPECIES 



continued. 



Geographical Distribution and Migration of Fish — Of Testacea — Of Insects — Moths 

 seen flying 300 Miles from Land — Botanical Geography — Dispersion of Plants 

 — Agency of Rivers and Currents — Marine Plants — Sargassum or Gulf-weed 

 Agency of Animals in the Distribution of Plants — Agency of Man, both volun- 

 tary and involuntary, in the Dispersion of Plants 3G9 



CHAPTER XLI. 



■ J 



INSULAR FLORAS AND FAUNAS CONSIDERED "WITH REFERENCE TO THE 



ORIGIN OF SPECIES. 



■ 



Volcanic Origin and Miocene Age of the Atlantic Islands — Islands once formed 

 have not been since submerged, nor united with other Islands — Arguments 

 against Continental Extension— Map showing the great Depth of the Ocean 

 between the Volcanic Archipelagos of the Western Atlantic and the Mainland 

 Submarine Volcanic Eruptions of the present Century — General Inferences to 

 be deduced from the Endemic and other Species of Animals and Plants in the 

 Atlantic Islands— From Mammalia— From Birds— From Insects— From Plants 

 —From Landshells— Small Number of Species of Landshells common to Madeira 

 and Porto Santo— Proportion of Species common to Madeira and the Dezertas 

 Contrast of the Testaceous Fauna of the British Isles and that of the Atlantic 

 Islands— Mode in which an Oceanic Island might become peopled with Land- 

 shells— Variability of Species not greater in Islands than on Continents . 402 



CHAPTER XLII. 



EXTINCTION OF SPECIES. 



Conditions which enable each Species of Plant to maintain its Ground against 

 others — Eq^uilibrium in the Number of Species how preserved — Agency of 



