6 THE COLOURS OF FLOWERS. 



blossom consists as a rule of a single stamen or a 

 single naked ovule, growing on a scale or an altered 

 leaf: and they display some remarkable analogies 

 with ferns, club-mosses, and other flowerless plants. 

 Of course, they never have petals or coloured organs. 

 The existing Gymnosperms may be regarded as 

 living survivors of a great class, once dominant, but 

 now nearly extinct; and their flowers probably still 

 preserve for us the original type of all blossoms, very 



FIG. 2. Diagram of typical primitive dicotyledonous fl >wer. a, carpels; b, 

 stamens ; c, petals ; d, sepals. Each whorl consists of five members. 



slightly altered by time and circumstances. This is 

 especially the case with the cycads, small tropical 

 trees of palm-like appearance, whose inflorescence is 

 the very simplest of all known flowering plants. The 

 other great division, that of the ANGIOSPERMS, has 

 always more fully developed blossoms, often entomo- 

 philous, and possessed of brilliant colours. It split up 

 again at an early period of its development into two 

 secondary large classes, those of the Monocotyledons 



