PREFACE. TEII v S o lume represents the accuml latede xperience of a decade in the p-esentation of experimental physiology to medical students. The scope of the book has naturally heen determined by the needs of meclical students who are preparing for the practice of clinical medicine and surgery. The preliminary lessons in Cytolor y are presented ss a feature of the volume. This introductory course has proven to be a most valuable accompaniment to the beginning X-ork in histology, as well as a most substantial foundation to general physiology. The arrangement of the chapters has been determined by two considerations l the degree of difficulty of the technique, and 2 the correlation of other work of the medical course, Cytology - the first chapter-involves the simplest microscopic technique, and the of cell life make the foundation of modern medicine and surgery. Electro-physiology involves a technique not too rlifficult for the esrIier moriths of medical study, and, at the same time, it forms a most valuable basis for the experimental work that follows. The order of the chapters on Circulation, Respiration, Hmna tology, and Digestion may easily be changed to suit the curriculum of the institution where the course is given. The esercises have for years been furnished my students in the forin of type-written syllibi, undergoing almost annual revision. They represent, therefore, a gradual evolution. At no time during this development of a practical course in experimental phgsiology has the author lost sight of the fact that his pupils were preparing for clinical practice. The experiments v vi PREFACE are carefully chosen and arranged to involve a considerable. amount of surgical work and to present to the student those fundamental facts and principles of physiology which form the basis of Internal Medicine. The author takes this opportunity to acknowledge the valuable assistance of his associate, Dr. C. J. Kurtz, who prepared the chapter on Normal Haematology, and of Professor Charles H. Miller, of the Department of Pharmacology, for his assistance in the preparation of the lessons on the physiological action of drugs. W. S. H. CONTENTS. PART I. EXPERIMENTAL GENERAL PHYSIOLOGY. CHAPTER I. I. Algae or Green Plants of Low Order . . . . . . . . 21 11. The Yeast Plant . . . . . . . . . . . . . . 26 111. Protozoa or One-celled Animals . . . . . . . . . . 28 IV. Normal Ciliary Motion . . . . . . . . . . . . 31 V. Ciliary Motion Modified by the Influence of CO, and An sthetics 33 VI. To Determine the Amount of Work Done by Cilia . . . . . 35 CHAPTER 11. VII. Electric Apparatus and Units of Measurement . . . . . VIII. Batteries . . . . . . . . . . . . . . . . IX. Methods of Varying the Strength of Current . . . . . . X. Muscle-nerve Preparation . . . . . . , . . . . . XI. Electric Stimulation and the Myogram . . . . . . . . XII...