x REPTILES, AMPHIBIANS AND FISHES 



CHAPTER III 



PAGE 



Distribution and Location 263 



Fresh-water fishes and marine fishes. Physostomous fishes originally 

 belonging to fresh water and Acanthopterygians which have returned 

 thither from the sea. Fresh-water fish-faunae of the great contin- 

 ents. Natural homes and habits in littoral zone. Tropical fishes. 

 Arctic and Antarctic fishes. America and Europe. North Pacific. 

 South Africa. India. New Zealand and Australia. Pelagic fishes. 

 Abyssal fishes. 



CHAPTER IV 

 Conditions of Life and Phenomena of Sex. ..... 291 



Food and feeding. Relations to temperature, light, and salinity. Influences 

 of seasons: migrations, hibernation, and aestivation. Association and 

 commensalism, parasitism. Relations of sexes, sexual dimorphism. 



- CHAPTER V 



Modes of Reproduction 314 



Oviparous and viviparous Elasmobranchs ; eggs of Chimaeroids. Nests 

 of Protopterus and Lepidosiren. Nest-building of Ganoids and 

 primitive fresh-water Teleosteans. Parental instincts in British 

 shore-fishes. Nest of the Sargasso. Fishes which incubate eggs 

 in the mouth. Pouch of the Pipe-fishes. Viviparous fishes. 

 Curious breeding habits of the Bitterling. 



CHAPTER VI 



Life-histories 341 



Life-histories of Teleostomi. Eggs of Clupeidae. Metamorphosis of 

 Angler and Pleuronectidas. Growth and Maturity. Diseases and 

 Parasites. Life-history of Eels. 



CHAPTER VII 

 Variation ........ ..... 359 



Continuous variations, their mathematical investigation and relation to 

 locality. Discontinuous variations or mutations, e.g. in fiat-fishes. 

 Variation under domestication. 



CHAPTER VIII 

 Adaptations 371 



Shape, symmetry, colour. Fiat-fishes. Synodontis. Locomotion. Fly- 

 ing-fishes. Respiration, gills and accessory organs. Air-bladder, 

 respiratory and hydrostatic function. Sense-organs and senses. 

 Hearing, relation of auditory organ to air-bladder. Sense-organs 

 of lateral line. Sight. Divided eyes of Anableps. Blind fishes. 



CHAPTER IX 



Adaptations (continued). Production of Sound, Light and Elec- 

 tricity 405 



Voice of fishes. Stridulating organs. Fishes which possess luminous 

 organs. Microscopic structure of luminous organs. Electric fishes. 

 Structure of electric organs. General remarks on evolution. 



