CO^TEI^TS. 



CHAPTER I. PAGE 

 INTRODUCTION 1 



CHAPTER II. 

 MOTION , . 9 



Experiments with the Muscles in our own Bodies. Muscle and 

 Nerve. The Action of Muscle. Structure of Muscle. Impor- 

 tance of Muscles. Laws of Muscle Action. Symmetrical Devel- 

 opment of Muscles. Relation of the Muscles and the Bones. 

 Levers. Study of one of the Long Bones. Joints. Locomotion. 



CHAPTER III. 



THE GENERAL, FUNCTIONS OF THE NERVOUS SYSTEM. SENSA- 

 TION AND MOTION 29 



The Brain and Spinal Cord of the Cat or Rabbit. Structure 

 of Nerves and Nerve Fibers. Cross-section of the Spinal Cord. 

 Reflex Action of the Spinal Cord of the Frog. Nerve Roots and 

 their Functions. Functions of the Spinal Cord. Voluntary In- 

 terference with Reflex Actions. The Nature of a Nervous Im- 

 pulse. Harmony in Muscle Action. Dependence of Nerves and 

 Muscles. 



CHAPTER IV. 

 CIRCULATION OF THE BLOOD 48 



The Blood and its Work. The Heart-beat and the Pulse. 

 A Drop of Frog's Blood. The Circulation of Blood in the Web of 

 a Frog's Foot. Heart and Lungs of a Pig, Sheep, or Calf. Dem- 

 onstration of the Action of the Heart. Reason for Injecting the 

 Arteries. The Distribution of the Arteries and Veins in a Cat 

 or Rabbit. The Action of the Frog's Heart. The Rate of the 

 Heart-beat. The Action of the Heart. The Beat of the Heart. 

 The Sounds of the Heart. Action of the Large Arteries. Ac- 



xvii x 



