i^( LIBRARY 



TABLE OF CONTENTS 



CHAPTER PAGE 



I. THE VERTEBRATE EYE 1 



The Bulb 

 Sclera 

 Cornea 

 Uvea 



Choroid and tapetum 

 Ciliary body 

 Iris 

 Lens 



II. THE RETINA 16 



Pigment Epithelium 

 Pars Optica Retinae 



III. THE STRUCTURE OF VISUAL CELLS ... 37 



The duplicity theory 



Structure of rods 



Structure of cones 



The basis for rod and cone classification 



IV. DIFFERENTIATION OF RETINAL ELEMENTS . 48 



Development of human retina 

 Development of amphibian visual cells 

 Development of rat visual cells 



V. RETINAL STRUCTURE AND ANIMAL HABITS . 60 



The double retina 



The retina of diurnal animals 



The retina of nocturnal animals 



VI. PHOTOMECHANICAL RESPONSES IN THE RETINA 74 



Pigment migration in vertebrate eyes 



Movements of rods and cones 



Factors influencing photomechanical movements 



Diurnal rhythms j~- / JT" C" 1/ 



