III.--DIFFERENTIATIONS AMONG THE OUTER TISSUES OF PLANTS 251 IV.--DIFFERENTIATIONS AMONG THE INNER TISSUES OF PLANTS 272 V.--PHYSIOLOGICAL INTEGRATION IN PLANTS 292 VI.--DIFFERENTIATIONS BETWEEN THE OUTER AND INNER TISSUES OF ANIMALS 299 VII.--DIFFERENTIATIONS AMONG THE OUTER TISSUES OF ANIMALS 309 VIII.--DIFFERENTIATIONS AMONG THE INNER TISSUES OF ANIMALS 323 IX.--PHYSIOLOGICAL INTEGRATION IN ANIMALS 373 X.--SUMMARY OF PHYSIOLOGICAL DEVELOPMENT 384 X^A.--THE INTEGRATION OF THE ORGANIC WORLD 396 PART VI.--LAWS OF MULTIPLICATION. I.--THE FACTORS 411 II.--_À PRIORI_ PRINCIPLE 417 III.--OBVERSE _À PRIORI_ PRINCIPLE 424 IV.--DIFFICULTIES OF INDUCTIVE VERIFICATION 432 V.--ANTAGONISM BETWEEN GROWTH AND ASEXUAL GENESIS 439 VI.--ANTAGONISM BETWEEN GROWTH AND SEXUAL GENESIS 448 VII.--THE ANTAGONISM BETWEEN DEVELOPMENT AND GENESIS, ASEXUAL AND SEXUAL 461 VIII.--ANTAGONISM BETWEEN EXPENDITURE AND GENESIS 467 IX.--COINCIDENCE BETWEEN HIGH NUTRITION AND GENESIS 475 X.--SPECIALITIES OF THESE RELATIONS 486 XI.--INTERPRETATION AND QUALIFICATION 497 XII.--MULTIPLICATION OF THE HUMAN RACE 506 XIII.--HUMAN POPULATION IN THE FUTURE 522 APPENDICES. A.--SUBSTITUTION OF AXIAL FOR FOLIAR ORGANS IN PLANTS 541 B.--A CRITICISM ON PROF. OWEN’S THEORY OF THE VERTEBRATE SKELETON 548 C.--ON CIRCULATION AND THE FORMATION OF WOOD IN PLANTS 567 D.--ON THE ORIGIN OF THE VERTEBRATE TYPE 599 D^2.--THE ANNULOSE TYPE 602 E.--THE SHAPES AND ARRANGEMENTS OF FLOWERS 608 F.--PHYSIOLOGICAL (OR CONSTITUTIONAL) UNITS 612 G.--THE INHERITANCE OF FUNCTIONALLY-CAUSED MODIFICATIONS 618 PART IV. MORPHOLOGICAL DEVELOPMENT. CHAPTER I. THE PROBLEMS OF MORPHOLOGY.