GENERAL CONSIDERATIONS. 129 



noticed the folding up of the calyx and corolla in wet 

 weather, or at sunset. The function exercised by the two 

 outer whorls of floral leaves is, in this case, purely protec- 

 tive, and the design of their close proximity to the stamens 

 and pistils is at once apparent ; that they may fold over the 

 stamens and pistils, and thus protect them from the effects 

 of the night dews and falling rain, which would otherwise 

 act injuriously on the pollen contained in the cells of 

 the anthers.. 



Fig. 26. 



Kg. 26. The different parts of a flower, a. The calyx ; b. the'corolla ; c. the 

 stamens ; d. the pistils. 



The reproductive organs of plants, popularly called their 

 flowers, are commonly the most showy and attractive parts. 

 To this rule, however, there are some exceptions. For 

 example, the radicle leaves of the rattlesnake plantain 

 (Groodyera puhesceus,) one of theNorth American Orchidese, 

 found in shady woods, far surpass the floral leaves in the 

 elegance of their form and coloring. This plant is much 

 prized in Europe, and is cultivated on account of the 

 beauty of its foliage. It bears a spike of greenish white 

 flowers of a very ordinary aspect ; the foliage of the plant, 

 on the contrary, is a deep rich green, most beautifully 



