Chapter III: Part III: The Evolution of Life

I. —Preliminary 415 II. —General aspects of the special-creation-hypothesis 417 III. —General aspects of the evolution-hypothesis 431 IV. —The arguments from classification 441 V. —The arguments from embryology 450 VI. —The arguments from morphology 468 VII. —The arguments from distribution 476 VIII. —How is organic evolution caused? 490 IX. —External factors 499 X. —Internal factors 508 XI. —Direct equilibration 519 XII. —Indirect equilibration 529 XIII. —The co-operation of the factors 549 XIV. —The convergence of the evidences 554 XIVA. —Recent criticisms and hypotheses 559 APPENDICES. A. —The general law of animal fertility 577 B. —The inadequacy of natural selection, etc. 602 C. —The inheritance of functionally-wrought modifications: a summary 692 D. —On alleged "spontaneous generation" and on the hypothesis of physiological units 696

FIRST PRINCIPLES By Herbert Spencer

CONTENTS