CONTENTS. Xill 



CHAPTER XIX. 



SUB-AQUATIC NESTS. VERTEBRATES. 

 Fishes as Architects. — The Sticklebacks and their general Habits. — The Fresh- 

 water Sticklebacks. — A jealous Proprietor. — Punishment of Trespassers. — 

 Form and Materials of the Nest. — Use of the Nest. — Cannibalistic Propensities. 

 — The Fifteen-spined Stickleback and its Form. — Its curious Nest. — Mr. 

 Couch's description of a Nest in a Rope's End. — Fishes of Guiana. — The Hassar 

 or Hardback, and its place in Zoology. — Nest of the Hassar. — Parental Watch- 

 fulness. — Singular Position of the Nest. — Habits of the Hassar Page 392 



CHAPTER XX. 



SUB-AQUATIC NESTS. INVERTEBRATES. 

 A Pool and its Wonders. — The Water Spider. — Its sub-aquatic Nest. — Convey- 

 ance of Air to the Nest. — The Diving-bell anticipated. — Character of the Air in 

 the Nest. — Mr. Bell's Experiments upon the Spider. — Life of the Water Spider. — 

 The Htdrachna. — The Caddis Flies and their Characteristics. — Sub-aquatic 

 Homes of the Larva. — Singular Varieties of Form and Material. — Life of a Cad- 

 dis. — Description of Nests in my own Collection. — Fixed Cases, and Modification 

 of Larva. — Singular Materials for Nest-building. — Corals and their general His- 

 tory. — The Coral of Commerce. — Development and Extension of the Coral. — 

 How fresh Colonies are founded. — Various Corals and their Growth. — Submarine 

 Tube-makers. — The Serpul.e and their general Habits. — The Operculum of the 

 Serpula. — The Terebell^e and their submarine Houses. — The Caddis Shrimp. 

 — Remarkable Analogy 397 



CHAPTER XXI. 

 SOCIAL HABITATIONS. 

 social mammalia. 

 The Beaver. — Its Form and aquatic Habits. — Need for Water, and Means used to 

 procure it. — Quadrupedal Engineering. — The Dam of the Beaver. — Erroneous 

 ideas of the Dam. — How the Beaver cuts Timber. — The Beaver in the Zoological 

 Gardens. — Theories respecting the Beaver's Dam. — How the Timber is fastened 

 together. — Form of the Dam, and mode of its Enlargement.— Beaver-dams and 

 Coral-reefs. — The House or Lodge of the Beaver. — Its Locality and Structure. — 

 Use of a subterranean Passage.— How Beavers are Hunted.— Curious Supersti- 

 tion. — "Les Paresseux" 431 



CHAPTER XXn. 

 SOCIAL BIRDS. 

 The Sociable Weaver Bird and its Country.— Description of the Bird.— Nest of 

 the Sociable Weaver.— How begun and how carried on.— Materials of the Nest. 

 —The Tree on which the Nest is built, and its Uses. —Dimensions of the Nest and 

 disastrous Consequences.— A Hottentot and a Lion.— Supposed Object of the So- 

 cial Nest.— Average Number of Inhabitants.— Analogy with Dyak Houses.— En- 

 emies of the Sociable Weaver, the Monkey, the Snake, and the Parrakeet 438 



CHAPTER XXIII. 

 SOCIAL INSECTS. 

 Arrangement of Groups.— Nests of Poltbia.— Curious Method of Enlargement.— 

 Structure of the Nests.— How concealed.— Various Modes of Attachment.— A cu- 

 rious Specimen.— The Hive-bee, and its claims to Notice.— General History of 



