PRINCIPLES OF THE GROWTH OF TREES. 



FLOWERS. 



The object of the flower is the production of seeds, and 

 through them the reproduction of new plants. The protect- 

 ing organs of each are, the 

 calyx outside, which is usual- 

 ly, not always, green ; and the 

 corolla, or flower leaves, of 

 various colors, which are next 

 within the calyx. The essen- 

 tial parts of the flowers are 

 the stamens &&& pistils. Fig. 8 

 represents an enlarged flower 

 of the cherry, cut through the middle, showing the small 

 calyx, the large corolla, the many stamens, and the single 

 pistil. Fig. 9 is a magnified flower of the purslane, showing 

 several pistils. The head of the stamen (b, Fig. 10) is called 



Fl0 ' 8 - Flower of the 



FIG. 9. Purslane Flower. 



FIG. io. Stamen. FIG. n. Pistil. 



the anther. It contains a powder called pollen, which is dis- 

 charged by the bursting of the anther, the pollen being the 

 fertilizing matter essential to the production and growth of 

 the new seed. The thread-like stalk of the stamen, a, is called 

 the filament. The pistil (Fig. 11) consists of the stigma, c, at 

 the top ; the style, b, its support ; and the ovary, a, or future seed- 

 vessel. The ovules, d, are the rudimentary seeds. The pollen 

 of the stamens falls on the stigma, and the egg-cells are fertil- 

 ized or impregnated, and seeds are the result. 



Sometimes the stamens and pistils are in different flowers, 

 on different parts of the plant. A familiar instance occurs in 

 Indian-corn, the " silk " being the pistils, and unless thes6 are 



