xvi CONTENTS 



^ PAOB 



Smooth Muscle Fiber 128 



Heart M iwclc Filwr 128 



Attachment of Muscles 129 



Joint Motions 129 



Muscle-Form in Relation to Muscle Duty 131 



Strength of Muscles 131 



Lonie M uscles 132 



Classes of Movements 133 



CHAPTER XIV 



Animal Sense Organs 



Adjustment.s in Lower Animals 135 



Receptors or Sense Organs 136 



Cla.sses of Sense Organs 136 



Internal Sense Organs 136 



Hunger 137 



Thirst 137 



Pain 138 



M uscle Sense 138 



Equilibrium 139 



The Contact Senses 139 



Touch 139 



The Temperature Sense 140 



The Chemical Senses 140 



Taste 141 



The Distance Receptors 142 



Smell 142 



The Organ of Hearing is the Ear 143 



Sight ^ 144 



The Perception of Form .". 144 



Image Formation 144 



Accessory Eye Strurtures 145 



The Perception of ( 'olor 146 



The Perception of Distance 146 



The Relation of Sight to Touch 147 



CHAPTER XV 



Nervous Correlation 



Origin of the Nervous System 148 



Correlation in Protozoa 148 



Correlation in Primitive Metazoa 149 



Correlation in Higher Forms 151 



The Structure of the Nervous System 152 



Simple Reflex Action ." 153 



Nervous Organization in Jointed Animals 154 



Complex Reflex Action 156 



Importance of the Front End of the Body 156 



The Advantage of the Distance Receptors 157 



Machinery for Using Paat Experience 158 



