BIOLOGY - PREFACE - THE present work is based chiefly upon the Introduction to the authors Manual of Zoology, much of which is given here in an unaltered form. A considerable portion, however, of the Introduction has been here recast, whilst fully two-thirds of the work consists of new matter. Illustrations also have been introduced wherever such appeared to be necessary. Many important subjects have, of course, been necessarily treated very superficially, or altogether omitted, as unsuitable for a merely elementary work. It is hoped, however, that most of those subjects are touched upon, a knowledge of which would be useful to the student of living or extinct forms of life, or to the general reader. -- C O N T E N T S -- CHAPTER I. PAGE Definition of Biology-Differences between dead and living bodies - Nature and conditions of life-Physical basis of life-Protoplasm-Connection between life and the matter of life-Organisation - Light - Air - Temperature - Death - Use of the term c vital force, . . . . 1-18 CHAPTER 11. Differences between animals and plants-Regnum Protisticum of Hzeckel-Higher plants distinguished from higher animals-Comparison of the lower animals with the lower plaats-Form-Internal structure-Chemical composition-Power of locomotion-Nature of the food, . . . . . 19-25 CHAPTER 111. Differences between different organisms-Morphology-Physiology - Specialisation of functions-Morphological type-Synopsis of the main divisions of the animal and vegetable kingdoms, 26-43 CHAPTER IV. Analogy - Homology-Serial Homology - Lateral Homology-Homogeny and Homoplasy - Homomorphism - Mimicry-Correlationofgrowth, . . . 44-5 CONTENTS. vii CHAPTER V. Principles of classification-Definition of Species-Genus-Family - Order-Class-Sub-kingdom-Impossibility of a linear classification, . . . . . . 56-63 CHAPTER VI. S Elementary chemistry of animals and plants-Chemistry of animals - Fats-Albumen-Fibrine - Caseine - Proteine of Mulder-Chemistry of vegetables-Starch-Cellulose-Sugar - Albuminous compounds of plants, . . 64-69 CHAPTER VII. Elementary structure of living bodies-Protoplasm or Bioplasmhfolecules - Cells-The cell-wall - The cell-contents - The nucleus-Cell-multiplication, . . . . 70-76 CHAPTER VIII. Physiological functioils of animals and plants-Animal and vege- table functions-Unicellular plants-Foraminifera-Vital force as manifested in the digestive process of plants, . 77-83 CHAPTER IX... --This text refers to an alternate Paperback edition.