56 ORGANS OF PLANTS. [CHAP. 



CHAPTER VII. 



THE VARIOUS ORGANS AND THEIR MODIFICATIONS. 



1. Further examination of Plant-structure. The importance 



of frequent practice in order to acquire facility in the use 

 of terms. 



2. (Organs of Nutrition). The Root originates from ? Tap- 



root fibrous root. Adventitious roots. Roots some- 

 times become thickened and tuberous. 



3. The Stem originates from? Axillary and terminal buds. 



Direction assumed by stems. Rhizome ; tubers ; bulbs. 

 The Stock. Remarkable modifications of stem- 

 structures. 



4. Leaves always lateral organs. Their arrangement upon the 



stem. Nodes and internodes. 



5. Cotyledonary leaves are temporary. Scale-leaves. Duration 



of leaves. 



6. Petiole and blade. Vernation. Venation. 



7. Outline of leaves. Simple and compound leaves. 



8. Simple undivided leaves. 



9. Simple divided leaves. 



10. Compound leaves. 



11. Apex and base. Mode of attachment to the stem. Margin, 



Surface. 



12. Stipules. Stipulate and ex-stipulate. 



13. Remarkable modifications of leaves. Phyllodes. 



14. (Organs of Reproduction). Arrangement of flowers upon 



the stem. The principal kinds of inflorescence. 



15. The Bracts ; bracteate, ebracteate. Involucre. 



1 6. ^Estivation of the calyx and corolla. 



17. Parts of a petal. Of a gamopetalous corolla, and of a 



gamosepalous calyx. 



18. Appendicular organs. 



19. The Stamens : .peculiar conditions of which are noticed 



under the Natural Orders in Part II. 



20. Homology of' the Pistil. 



21. Carpellary theory. A review of various forms of pistil. 



The sutures of a carpel. The ovary and its cells. 



