vi CONTENTS 



CHAPTER LVIIL SENSE-ORGANS OF BACKBONELESS ANI- 

 MALS (INVERTEBRATA) AND BACKBONED ANIMALS (VERTE- 

 BRATA) 



Page 



The Nature and Uses of Sense-Organs; Organic Sensations; Special Senses- - 24 



TOUCH General Nature: Haptic and Thermal Sensations; Tactile Organs of 

 Zoophytes, Annelids, Arthropods, and Vertebrates. Pacinian Bodies and the 

 Pressure- Sense. Organs of Active Touch - - 25 



TASTE General Nature: Gustatory Organs of Annelids, Insects, Molluscs, and 



Vertebrates; Taste-Buds -.- 29 



SMELL General Nature: Distance-Senses (Telaesthetic Senses); Olfactory Organs 



of Arthropods, Molluscs, and Vertebrates 30 



BALANCE AND HEARING General Nature 32 



Balancing Organs of Jelly-Fishes (Hydrozoa] Otocysts and Tentaculo- 



cysts and their Uses 33 



Balancing Organs in Segmented Worms (Annelida] Earth-Worms, Oto- 

 cysts of Lug- Worms (Arenicold) 34 



Balancing Organs in Molluscs (Mollusca) Otocysts of Bivalves (Lamelli- 

 branchia), Snails and Slugs (Gastropoda), and Head-footed Molluscs 

 (Cephalopoda) - 34 



Organs of Balance and Hearing in Crustaceans (Crustacea) Otocysts of 

 Lobsters, Prawns, Shrimps, and Crabs ; Otocysts in Tail of Opossum 

 Shrimp (My sis] ; Sound-producing Crustaceans Rock- Lobster (Pali- 

 nurus\ Musical Strand- Crab (Ocypoda macrocera), Squeaker Crab 

 (Psopheticus stridulans] 35 



Organs of Balance and Hearing in Insects (Insectd] Chordotonal Organs : 



Musical Organs of Grasshoppers, Green Grasshoppers, and Crickets - 37 



Organs of Balance and Hearing in Backboned Animals (Vertebratd) 

 Otocyst in the Brain of Larval Ascidiane (Urochorda}\ Structure 

 and Uses of the Auditory Organs of Aquatic- and Land- Vertebrates - 38 



SIGHT Skin-Seeing (Dermatoptic Vision) of Earth-Worms and Bivalve Molluscs - 39 



Direction-Eyes Euglena, Jelly-Fishes (Hydrozod), Star-Fishes and Sea- 

 Urchins (Echinodermata\ Segmented Worms (Annelida), Arrow- 

 Worms (Chcetognatha), and Limpet (Patella) 40 



Picture-Eyes Compound Eyes of Crustaceans and Insects. Camera 

 Eyes of Annelids, Arthropods, and Molluscs. Camera Eyes of Verte- 

 bratesStructure and Development; Visual Organs of the Double- 

 Eyes (Anableps] ; Pineal Eyes of certain Reptiles 43 



ANIMAL INSTINCT AND INTELLIGENCE 



CHAPTER LIX. GENERAL PRINCIPLES-INSTINCT AND IN- 

 TELLIGENCE IN HIGHER BACKBONELESS ANIMALS 

 (INVERTEBRATA) AND BACKBONED ANIMALS (VERTEBRATA) 



GENERAL PRINCIPLES Reflex Action, Instinct, Intelligence, Reason - - - 49 



