CHAPTER I.
THE NATURE OF ANIMAL LIFE.
| The characteristics of animals | 2 |
| The relation of animals to food-stuffs | 15 |
| The relation of animals to the atmosphere | 15 |
| The relation of animals to energy | 16 |
CHAPTER II.
THE PROCESS OF LIFE.
| Illustration from respiration | 21 |
| Illustration from nutrition | 25 |
| The utilization of the materials incorporated | 27 |
| The analogy of a gas-engine. Explosive metabolism | 30 |
CHAPTER III.
REPRODUCTION AND DEVELOPMENT.
| Reproduction in the protozoa | 37 |
| Fission in the metazoa | 41 |
| The regeneration of lost parts | 41 |
| Reproduction by budding | 42 |
| Sexual reproduction | 42 |
| Illustration of development | 51 |
| Parental sacrifice | 56 |
| The law of increase | 58 |
CHAPTER IV.
VARIATION AND NATURAL SELECTION.
| The law of persistence | 61 |
| The occurrence of variations | 63 |
| Application of the law of increase | 76 |
| Natural selection | 77 |
| Elimination and selection | 79 |
| Modes of natural elimination illustrated | 80 |
| Protective resemblance and mimicry | 82 |
| Selection proper illustrated | 93 |
| The effects of natural selection | 95 |
| Isolation or segregation | 99 |
| Its modes, geographical, preferential and physiological | 99 |
| Its effects | 108 |
| Utility of specific characters | 110 |
| Variations in the intensity of the struggle for existence | 112 |
| Convergence of characters | 117 |
| Modes of adaptation: Progress | 119 |
| Evolution and Revolution | 120 |
CHAPTER V.
HEREDITY AND THE ORIGIN OF VARIATIONS.
| Heredity in the protozoa | 123 |
| Regeneration of lost parts | 124 |
| Sexual reproduction and heredity | 129 |
| The problem of hen and egg | 130 |
| Reproductive continuity | 131 |
| Pangenesis | 131 |
| Modified pangenesis | 134 |
| Continuity of germ-plasm | 138 |
| Cellular continuity with differentiation | 142 |
| The inheritance or non-inheritance of acquired characters | 146 |
| Origin of variations on the latter view | 149 |
| Hypothesis of organic combination | 150 |
| The extrusion of the second polar cell | 153 |
| The protozoan origin of variations | 156 |
| How can the body influence the germ? | 159 |
| Is there sufficient evidence that it does? | 162 |
| Summary and conclusion | 175 |
CHAPTER VI.
ORGANIC EVOLUTION.
| The diversity of animal life | 177 |
| The evolution theory | 181 |
| Natural selection: not to be used as a magic formula | 183 |
| Panmixia and disuse | 189 |
| Sexual selection or preferential mating | 197 |
| Use and disuse | 209 |
| The nature of variations | 216 |
| The inheritance of variations | 223 |
| The origin of variations | 231 |
| Summary and conclusion | 241 |
CHAPTER VII.
THE SENSES OF ANIMALS.
| The primary object of sensation | 243 |
| Organic sensations and the muscular sense | 244 |
| Touch | 245 |
| The temperature-sense | 249 |
| Taste | 250 |
| Smell | 257 |
| Hearing | 261 |
| Sense of rotation or acceleration | 269 |
| Sight | 273 |
| Restatement of theory of colour-vision | 278 |
| Variation in the limits of colour-vision | 281 |
| The four types of "visual" organs | 293 |
| Problematical senses | 294 |
| Permanent possibilities of sensation | 298 |
CHAPTER VIII.
MENTAL PROCESSES IN MAN.
| The physiological aspect | 302 |
| The psychological aspect | 304 |
| Sensations: their localization, etc. | 306 |
| Perceptual construction | 312 |
| Conceptual analysis | 321 |
| Inferences perceptual and conceptual | 328 |
| Intelligence and reason | 330 |
CHAPTER IX.
MENTAL PROCESSES IN ANIMALS: THEIR POWERS OF PERCEPTION AND INTELLIGENCE.
| The two factors in phenomena | 331 |
| The basis in organic evolution | 336 |
| Perceptual construction in mammalia | 338 |
| Can animals analyze their constructs? | 347 |
| The generic difference between the minds of man and brute | 350 |
| Perceptual construction in other vertebrates | 350 |
| "Understanding" of words | 354 |
| Perceptual construction in the invertebrates | 356 |
| "The psychic life of micro-organisms" | 360 |
| The inferences of animals | 361 |
| Intelligent not rational | 365 |
| Use of words defined | 372 |
| Language and analysis | 374 |
CHAPTER X.
THE FEELINGS OF ANIMALS: THEIR APPETENCES AND EMOTIONS.
| Pleasure and pain: their organic limits | 379 |
| Their directive value | 380 |
| An emotion exemplified | 382 |
| Sensitiveness and sensibility | 385 |
| The expression of the emotions | 385 |
| The postponement of action | 385 |
| The three orders of emotion | 390 |
| The capacities of animals for pleasure and pain | 391 |
| Sense-feelings | 393 |
| Some emotions of animals | 395 |
| The necessity for caution in interpretation | 399 |
| The sense of beauty | 407 |
| Can animals be moral? | 413 |
| Conclusion | 414 |
CHAPTER XI.
ANIMAL ACTIVITIES: HABIT AND INSTINCT.
| The nature of animal activities | 415 |
| The outer and inner aspect | 417 |
| The inherited organization | 419 |
| Habitual activities | 420 |
| Instinctive activities | 422 |
| Innate capacity | 426 |
| Blind prevision | 429 |
| Consciousness and instinct | 432 |
| Mr. Romanes's treatment of instinct | 434 |
| Lapsed intelligence and modern views on heredity | 435 |
| Three factors in the origin of instinctive activities | 447 |
| The emotional basis of instinct | 449 |
| The influence of intelligence on instinct | 452 |
| The characteristics of intelligent activities | 456 |
| The place of volition | 459 |
| Perceptual and conceptual volition | 460 |
| Consciousness and consentience | 461 |
| Classification of activities | 462 |
CHAPTER XII.
MENTAL EVOLUTION.
| Is mind evolved from matter? | 464 |
| Kinesis and metakinesis | 467 |
| Monistic assumptions | 470 |
| The nature of ejects | 476 |
| The universe as eject | 478 |
| Metakinetic environment of mind | 481 |
| Conceptual ideas not subject to natural selection | 483 |
| Elimination through incongruity | 486 |
| Interneural evolution | 490 |
| Interpretations of nature | 492 |
| Can fetishism have had a natural genesis? | 493 |
| The origin of interneural variations | 496 |
| Are acquired variations inherited? | 497 |
| Summary and conclusion | 501 |
