CONTENTS 



HALF-VOL. VII 



NERVOUS SYSTEM AND SENSE-ORGANS 



CHAPTER LVII. GENERAL PRINCIPLES NERVOUS SYSTEMS 

 OF BACKBONELESS ANIMALS (INVERTEBRATA) AND BACK- 

 BONED ANIMALS (VERTEBRATA) 



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GENERAL PRINCIPLES Properties of Protoplasm : Sensitiveness and Spontaneity. 



Stimuli : Reaction of Protozoa to Stimuli - I 



NERVOUS SYSTEMS OF BACKBONELESS ANIMALS 

 (INVERTEBRATA) 



Division of Labour in Cell-Communities 5 



NERVOUS SYSTEMS OF ZOOPHYTES (CCELENTERATA) Ectoderm and Endoderm : 



Nerve-Cells and Nerve-Fibres, Neurons ; Sea-Anemones ; Jelly-Fishes 5 



NERVOUS SYSTEMS OF SEGMENTED WORMS (ANNELIDA) Nerve-Ring and 

 Nerve-Cord in Earth-Worm, &c.; Head and Brain; Reflex Action; Visceral 

 Nervous System ; Comparison with Nemertine Worms (Nemerted) - - - 7 



NERVOUS SYSTEMS OF JOINTED-LIMBED INVERTEBRATES (ARTHROPODA) 



Comparison with Annelids - - - 10 



Nervous Systems of Crustaceans (Crustacea) Apus, Crayfish, and Crab - 12 



Nervous Systems of Air-breathing Arthropods (Tracheatd) Peripatus, 



Centipedes and Millipedes, Scorpions and Spiders, Insects 14 



NERVOUS SYSTEMS OF MOLLUSCS (MOLLUSCA) Mail-Shells (Chiton), Snails and 

 Slugs (Gastropoda), Bivalves (Lamellibranchia}^ Tusk-Shells (Scaphopoda)^ 

 Head-footed Molluscs (Cephalopoda) 16 



NERVOUS SYSTEMS OF BACKBONED ANIMALS (VERTEBRATA) 



Brain, Spinal Cord, Sympathetic Nervous System, Spinal Nerves, Cranial Nerves ; 



Development of Nervous System - - - - - - - - -19 



THE BRAIN OF VERTEBRATES Development and Structure; Increase of Com- 

 plexity in ascending the Scale 20 



