Xll CONTENTS. 



PAGE 



PROSENCHYMA 76 



Prosenchyma proper 77 



Woody Fibres 80 



Tracheids 82 



Trachese, or Ducts 84 



Liber-fibres 87 



CRIBROSE-CELLS 91 



LATEX-CELLS 94 



Receptacles for Secretions 97 



Intercellular Spaces 99 



CHAPTER III. 



MINUTE STRUCTURE AND DEVELOPMENT OF THE ROOT, 

 STEM, AND LEAF OF PH^ENOGAMOUS PLANTS. 



The Systems of Tissues 102 



Structure of a Fibro-vascular Bundle 103 



THE ROOT 106 



Primary Structure 106 



The Root-cap 107 



The Piliferous Layer 108 



The Central Cylinder 110 



Secondary Structure 112 



THE STEM 118 



Primary Structure 119 



The Epidermis 119 



Primary Cortex 119 



Primary Bundles 120 



Pith 124 



Medullary Rays 124 



Course of the Bundles 125 



Secondary Structure . . 135 



Of Monocotyledons 135 



Of Dicotyledons 136 



Changes by Growth 137 



Anomalous Stems , 138 



Spring and Autumn Wood . . <. 138 



Annual Layers 139 



Color of Wood , . . 141 



Preservation of Wood 142 



Density , 144 



Bark 147 



Secondary Liber 147 



Cork 148 



Injuries of the Stem 149 



Lenticels 151 



Grafting 152 



