ENLARGEMENT 417 Of axile organs, 418--Knaurs, 419--Enlargement of buds, 420--Of flower-stalk, 421--In pears, 423--Of placenta, 424--Of leaves, 426--Development of parts usually abortive, 427--Enlargement of perianth, 428--Of androecium, 430--Of gynoecium, 430--Of fruit, 431--Alterations of consistence, 432. CHAPTER II. ELONGATION 488 Elongation of root, 434--Of inflorescence, 434--Of flower-stalks, 435--Of leaves, 437--Of parts of flower, 438--Of thalamus and placenta, 440--Apostasis, 440. CHAPTER III. ENATION 443 Excrescences from axile organs, warts, 444--Enation from leaves, 445--From sepals, 448--From petals, 448--Catacorolla, 451--Enation from stamens, 453--From carpels, 453. PART II.--ATROPHY 454 CHAPTER I. ABORTION 455 Abortion of axile organs, 455--Of receptacle, 457--Of leaves, 458--Of perianth, calyx, and corolla, 460--Of stamens, 463--Of pollen, 463--Of pistil, fruit, &c., 464--Of ovules, 466--Depauperated ferns, 466--General remarks, 467. CHAPTER II. DEGENERATION 470 Formation of scales, 470--Of hairs, 472--Of glands, 473--Of tendrils, 473. GENERAL CONCLUSIONS. General morphology of the leaf and axis, 476.--Homology, 476--Special morphology, 479--Calyx-tube, 480--Androecium, 482--Inferior ovary, 482--Placentation, 483--Structure of the ovule, 484--Leaves of Conifers, 484--Relative position of organs, 484--Law of alternation, 485--Co-relation, 486--Compensation, 488--Teratology and classification, 488. APPENDIX. Double flowers, varieties of, 491--Causes of production, 491--Relation to variegated foliage, 497--List of plants producing, 499. NOTE 508 INDEX TO SUBJECTS 511 INDEX OF NAMES OF PLANTS 517 LIST OF ILLUSTRATIONS. FIG. PAGE