V] PARTS OF THE FLOWER 43 



the central region of the flower he finds a number of 

 small, green, hollow carpels, each of which, on careful 

 examination with a lens, will be seen to be like a 

 miniature short inflated pea-pod with one pea in it, and, 

 like the pea-pod, suggestive of a folded green leaf. 



By choosing suitable examples from a number of 

 different flowers, it is easy to see that some show the 

 leaf-like characters of the sepals better than others ; others, 

 again, illustrate these features in the petals, or the stamens, 

 or the carpels respectively, and serve as examples. 



The sepals, which form the outer covering of the 

 flower, known collectively as the calyx, are commonly 

 more leaf-like than the other parts of the flower, as is 

 especially evident in many Roses (Fig. 14). 



The petals form the more internal of the two sets of 

 organs covering the ordinary flower, and are known col- 

 lectively as the corolla : their essentially leaf-like nature 

 is shown in monstrous flowers such as occasionally occur 

 in Clover, Roses, &c. 



The stamens are termed, collectively, the andrcecium, 

 and constitute the third set of organs in the typical flower. 

 Their essentially leaf-like characters come out on com- 

 paring the gradual transition from petals to stamens in 

 Water-lilies, and on examination of the male cone of a 

 Pine, as well as in certain monstrosities where they revert 

 to green leaves. In ordinary " double " flowers, also, it is 

 a common event to find stamens reverting to the petaloid 

 condition, while the same phenomenon is normal in some 

 plants e.g. Scitaminece. 



The carpels, collectively termed the pistil or gynwcium, 

 often show sufficient evidence of their leaf-like characters 

 to suggest the homology, as in the female flowers (cones) 

 of the Pines, in Peas, Beans and other Leguminosae, in 

 the Double Cherry, in Mignonette, Sterculias, &c. 



