320 CONTENTS. 



Of the Elephant, its sagacity, docility, utility, &c 253260 



Of the Dog, Horse, Oxen of the Hottentots 260265 



Articulation of words by some birds 265266 



Musical and imitative faculties of singing birds 266 



Effects of Domestication upon different animals, in size, shape, color, &c. 266268 

 Of Albinoes 268-269 



CHAPTER XIII. 



OP THE COVERING, MIGRATION, AND TORPIDITY OP ANIMALS. 



Man capable of inhabiting in every climate 269 



Constitutions of other animals not so accommodating 269 270 



Means by which they are protected against climate and seasons 270 



1. Changes in the color and quantity of hair, fur, feathers, <fec., in 



different climates and seasons 271 



How these changes operate to maintain the proper animal tem- 



pemture 271 



2. Migrations of Birds. Swallows, question as to their torpidity or 



migration 272273 



British species of Swallows ; their times of appearance and disap- 

 pearance 273 274 



Different opinions concerning the periodical appearance and dis- 

 appearance of Swallows 274 279 



Of Summer and Winter Birds of Passage ; their residence in dif- 

 ferent seasons 279 



Of the Wild Goose, Solan Geese or Gannets in the Frith of Forth, 



and at St. Kilda 279280 



Of partial migrations. Circumstances attending migrations 280289 



The great rapidity of the flight of Birds removes one objection to 



their migration 28228? 



Migration not peculiar to Birds. Migrations of the human species 283 281 



Migrations of Quadrupeds and of Reptiles 284285 



Migrations of Fishes ; Salmon, Herring, Mackerel, &c., and of the 



Land-crab 285 28i. 



Migrations of Insects. Migration to a certain extent a universal 



principle 289 29f 



3. Torpidity. Quadrupeds which become torpid 290291 



Temperature diminished in the torpid state 29k 



Diminution in the force and rapidity of the circulation 291 



Causes of torpidity, and some phenomena attending it 291 



Of the torpidity of Birds, Reptiles, &c 



CHAPTER XIV. 



OP THE LONGEVITY AND DISSOLUTION OF ORGANIZED 

 BODIES. 



Dissolution of organized bodies a general law of nature ..... S93 



of the life of Man 893 1 



