. CONTENTS. XV 



TAGE 



System of the Protozoa — Ledenf eld's Investigations on a Nervous 

 System in the Porifera — The Nervous System of the Coslenterata : 

 Researches of Kleinenberg, Romanes, Haeokel, Hertvrig, and 

 others ; Experiments of Romanes on the Nervous System of the 

 Medusce; Eimer's Investigations on Gtenoplwra — The Nervous 

 System of the Echinodermata : Researches of Romanes, Bwart, 

 Fredericq, Prouho, and Hamann ; Internal and External Nerve- 

 plexuses of Echinus — Nervous Systems of the Trichoscolices, Anne- 

 lida, Nematoscolices, Ohcetognatha, Prototracheata, and Mi/riapoda — 

 The Nervous Systems of the Insecta : The Cerebral Ganglion or 

 Brain — The Nervous Systems of the Arachnida and Crustacea .- 

 Investigations of Sars, Fredericq, Vandevelde, and Griffiths — The 

 Nervous Systems of the Polyzoa, Bracliiqpoda, Mollusca, and 

 Tunieata, &o. ... ..... 293 



CHAPTER XI. 



The Organs of Special Sense, &c., in the Invertebrata : Tactile Sensi- 

 bility and Sight in the Protozoa and Porifera — The Ccelenterata : 

 Rudimentary Eyes and Olfactory Organs in the Medusce — The 

 Echinodermata : Tactile Sensibility ; Sense of Smell : Experiments 

 of Griffiths; Sense of Hearing ; Eyes: Researches of Romanes 

 and Ewart — The Sense-organs in the Trichoscolices, Annelida, 

 Nematoscolices, Ohcetognatha, and Myriapoda — Seiise-organs in the 

 Insecta : Tactile Organs ; The Senses of Taste, Smell, and Hearing ; 

 Simple and Compound Eyes of Insects, Mosaic Vision; The 

 " Voices " of Insects — Sense-organs in the Crustacea : Blind Cave- 

 crabs, Cirripedia, Crayiishes, &c. — Sense-organs in the Mollusca : 

 Organs of Touch, Taste, Smell, Hearing, and Sight ; The Cepha- 

 lopodEye — Intelligence or Reason in certain Invertebrates, &c. . 345 



CHAPTER XII. 



Movements and Locomotion in the Invertebrata : In the Protozoa : 

 Pseudopodia, Flagella, and Cilia as locomotive organs ; Researches 

 of Dallinger and Drysdale ; The Muscular Fibre in the Peduncle 

 of Vcyrticella — Movements in the Porifera — Locomotion, &c., in the 

 Ccelenterata: Researches of Romanes — Locomotion, &c., in the 

 Trichoscolices, Annelida, Nematoscolices, and Myriapoda; Loco- 



