INTRODUCTION 41 



The character of the outer perianth is a point of 

 interest in the life-history of the flower. Usually the 

 calyx serves as a protection or as a support for the 

 corolla. The former, as a rule, is not brilliantly 

 coloured, except in many Monocotyledons and some 

 Dicotyledons. It may even be absent, and the 

 flow^ers are then usually wind-pollinated. The calyx 

 may also serve as a means of dispersal of the fruit 

 when it is persistent, but frequently it falls, like the 

 petals, when the important function of pollination 

 has been performed. It may also serve as a protection 

 or covering for the fruit or seeds. The arrangement 

 of the sepals is also important in classification. The 

 number of parts or the absence of sepals in this case 

 again serves as a basis for arrangement. Sepals may 

 be either reduced in number or suppressed. They 

 may also become fused with other parts, and may be 

 irregular as in the case of the corolla. 



The suppression or reduction of the calyx in such 

 groups as the Compositae would seem to be connected 

 with a general economy of parts for the closer arrange- 

 ment and greater production of essential parts, for 

 seed formation. 



The corolla is generally brightly coloured when 

 not white, when, however, it is equally conspicuous, 

 especially at night. The character of the corolla in 

 relation to insects especially, and the particular 

 arrangements of the flower in relation to pollination 

 are perhaps the most interesting features in the life- 

 history of the plant. Being visible features they are 



