XU CONTENTS. 



Chap. II. page 



Of the Roots of Vascular Plants 208 



Sect. I. Comparison of Stems and Roots ib. 



II. Of the Parts of Roots, and of their various Forms . . 216 



III. Of Subterranean and Root-like Stems or Branches . 222 



IV. Of Adventitious Roots 223 



V. Of the Functions of Roots 225 



Chap. III. 



Of the Leaves of Vascular Plants 230 



Sect. I. Of the general Structure of Leaves ih. 



II. Of the Distinction between the Petiole and the Limb 



of Leaves 238 



III. Of the Disposition of the Nerves in the Limb of the 



Leaf 248 



IV. Of Lobed Leaves 255 



V. Of Compound Leaves 262 



VI. Of the Cavities of Leaves 271 



VII. Of the Disposition of the Leaves upon the Stem , . 274 



VIII. Of Stipules .282 



IX. Of the Union of Leaves with each other and with other 



Organs 288 



X. Of the Irregularity of foliaceous Organs 291 



Xr. Of the History of Leaves at different Periods of their 



Existence 293 



XII. Of the Functions of Leaves, and of the Means of sup- 

 plying their place in Leafless Plants 301 



Chap. IV. 



Of the Nutritive Organs of Cellular Plants 306 



Sect. I. General Considerations ib. 



II. Of Mosses 308 



III. Of the Hepaticae . 314 



IV. Of Lichens 316 



V. Of Fungi 319 



VL Of the Algae 322 



Plates. 



