CONTENTS. IX 



CHAPTER IV. OF THE STEM OR ASCENDING AXIS 93 

 SECT. I. ITS GENERAL CHARACTERISTICS AND MODE OF 



GROWTH ....... 93 



Nodes and Internodes ....... 94 



Buds 95 



SECT. II. RAMIFICATION ....... 98 



Branches 98 



Adventitious and Accessory Buds ..... 100 



Propagation from Buds ....... 103 



SECT. III. THE KINDS OF STEM AND BRANCHES . . 103 



Herbs, Shrubs, and Trees 103 



Stolons, Runners, Tendrils, Thorns, &c. .... 104 



Subterranean Modifications ...... 106 



Rhizoma or Rootstock . . ... . . 107 



Tuber, Corm 108 



Bulbs and Bulblets . 110 



SECT. IV. THE INTERNAL STRUCTURE OF THE STEM . 112 



SECT. V. THE EXOGENOUS OR DICOTYLEDONOUS STEM . 114 



The First Year's Growth 115 



The Pith and Medullary Sheath 116 



The Wood 117 



The Bark . . 118 



The Second Year's Growth in Diameter . . . 121 



Annual Increase of the Wood ...... 122 



Sap-wood and Heart-wood 124 



SECT. VI. THE ENDOGENOUS OR MONOCOTYLEDONOUS STEM 129 



SECT. VII. OF THE THEORETICAL STRUCTURE OF THE STEM 131 



Origin of the Wood . 131 



The Plant a Composite Being ...... 137 



Phytons 139 



CHAPTER V. OF THE LEAVES ..... 140 



SECT. I. THEIR ARRANGEMENT 



Phyllotaxis . 141 



Vernation or Praefoliation ... 151 



SECT. II. THEIR STRUCTURE AND CONFORMATION . . 152 

 Anatomy of the Leaf ....... 



Stomata I 57 



Development of the Leaf 160 



