This Primer is an attempt to explain in the most simple manner possible some of the most important and most general facts of Physiology, and may be looked upon as an introduction to the Elementary Lessons of Professor Huxley. In my descriptions and explanations I have supposed the reader to be willing to handle and examine such things as a dead rabbit and a sheep’s heart; and written accordingly, I have done this purposely, from an increasing conviction that actual observation of structures is as necessary for the sound learning of even elementary physiology, as are actual experiments for chemistry. At the same time I have tried to make my text intelligible to those who think reading verbal descriptions less tiresome than observing things for themselves. It seemed more desirable in so elementary a work to insist, even with repetition, on some few fundamental truths, than to attempt to skim over the whole wide field of Physiology. I have therefore omitted all that relates to the Senses and to the functions of the Nervous System, merely just referring to them in the concluding article. These the reader must study in the “Elementary Lessons.” M. FOSTER. TABLE OF CONTENTS. ART. SECT. I. INTRODUCTION. PAGE 1. “ What Physiology is 1 2. “ Animals move of their own accord 1 3. “ Animals are warm 3 4. “ Why animals are warm and move about--they burn 4 5. “ The need of Oxygen 5 6. “ The waste matters 5 II. THE PARTS OF WHICH THE BODY IS MADE UP. 7. “ The Tissues 7 8. “ The cavities of the Thorax and Abdomen 9 9. “ The Vertebral Column 12 10. “ Head and Neck 15 11. “ Nerves 18 12. “ General arrangement of all these parts 19 III. WHAT TAKES PLACE WHEN WE MOVE. 13. “ The Bones of the Arm 21 14. “ The structure of the Elbow Joint 23 15. “ Other joints in the body 25 16. “ The arm is bent by the contraction of the Biceps Muscle 26 17. “ How the will makes the Biceps Muscle contract 32 18. “ The power of a muscle to contract depends on its being supplied with blood 35 19. “ It is the food in the blood which gives the muscle strength 37 20. “ The continual need of food 38 IV. THE NATURE OF BLOOD.