CONTENTS. Vii 



2. THEIR STRUCTURE AND FORMS AS FOLIAGE 87 



Internal Structure or Anatomy 87 



Parenchyma-cells 88 



Epidermis, Stomata or Breathing-pores 89 



Framework, Venation 90 



Parallel-veined or Nerved Leaves , . . 91 



Reticulated or Netted-veined Leaves 92 



Pinnately or Feather-veined and Palmately or Radiately 



Veined 93 



Forms as to Outline 94 



Forms as to Extremity 96 



Forms as to Margin or Special Outline and Dentation ... 97 



Lobation or Segmentation 98 



Number and Arrangement of Parts 99 



Compound Leaves, Pinnate and Palmate or Digitate, &c. . . 100 



Petiole or Leafstalk 104 



Stipules, Ligule, Stipels 105 



Leaves in unusual Modifications 106 



Such as Inasquilateral, Connate, Perfoliate 107 



Vertical and Equitant 108 



Without distinction of Parts 109 



Stipules serving for Blade 109 



Phyllodia, or Petioles serving for Blade 110 



3. LEAVES SERVING SPECIAL OFFICES 110 



Utilizing Animal Matter 110 



Ascidia or Pitchers Ill 



Sensitive Fly-traps 113 



Leaves for Storage 115 



Bulb-scales and Bud-scales 116 



CHAPTER IV. PHYLLOTAXY, OR LEAF-ARRANGEMENT . 119 



SECTION I. DISTRIBUTION OF LEAVES ON THE STEM .... 119 



Phyllotaxy either Verticillate or Alternate, Cyclical or Spiral 119 



Verticillate or Cyclical Arrangement 120 



Alternate or Spiral Arrangement 121 



Its Modes and Laws 122 



Relation of Whorls to Spirals 129 



Hypothesis of the Origin of Both 130 



Fascicled Leaves 131 



SECTION II. DISPOSITION OF LEAVES IN THE BUD 132 



Vernation and Estivation; the Modes ........ 132 



Direction, Dextrorse and Sinistrorse 140 



