CHAP. VII. J ORGANS OF PLANTS. 57 



18. The Stamens. Peculiar conditions of which are noticed under 



the Natural Orders in Part II. 



19. The Pistil. Homology of foliage-leaves and cai'pels. 



20. Carpellary theory. A review of various forms of pistil. The 



sutures of a carpel. The ovarj' and its cells. 



21. Placentation. 



22. Fruit and seed. Pei'icarp. 



23. Suppression of cells of the ovary during maturation of the fruit. 



Changes in different layers of the pericarp. Fruit of Mango, 

 Pomegranate, Orange, Gourd or Water Melon. Dry syncarpous 

 fraits ; capsule, nut. Dehiscent and indehiscent fruits. Achenes 

 of Ranunculus and Bramble. Mulberry. Fig compared with 

 fruit of Rose. Enumeration of principal kinds of fruit. 



24. Number of seeds in the fruit. Albuminous and exalbuminous 



seeds. 



I. We now proceed to examine some of the different 

 forms assumed by the Vegetative, or, as we previously 

 termed them, the Nutritive, organs of Plants — viz. the 

 Root, Stem, and Leaves. Also, so far as previous chapters 

 leave it needful, the general character of the Reproductive 

 Organs, and especially the structure of the Fruiu 



In order to avoid ambiguity, we shall find it necessary 

 to employ not only the substantive terms used by botanists 

 to denote the several organs themselves, but also the more 

 important of the adjective terms employed to denote special 

 modifications of the same. The necessary terms are very 

 simple, and easily learned, and, with moderate perseverance, 

 facility in applying them may soon be acquired. 



By carefully examining one plant every day, first filling 

 up a schedule from the flower, and then writing out, with 

 these lessons before you, a description of all the organs in 

 detail, very considerable progress will be made in practical 

 botany in the course of a single season. 



In this and the following chapter, devoted to the structure 

 of the various organs, whenever it has appeared desirable for 

 the sake of illustration, I have named a common plant, which 



F 2 



