APPENDIX II 



THE STEUCTURE OF THE FLOWER 



The botanist's idea of what constitutes a flower is not exactly 

 the same as that implied in our common speech. Even small, 

 green, inconspicuous objects, such as the little structures which 

 go to make up a Willow catkin, come under the botanical 

 category of flowers, though they do not possess the brightly- 

 coloured, expanded petals which are ordinarily associated 

 with the word. The definition of a flower, from a botanical 

 standpoint, is that it is a shoot, bearing leaves specialised for 

 purposes of reproduction. The shoot is, as it were, telescoped, 

 so that the floral leaves, instead of being separated from one 

 another, like the leaves on an ordinary branch, are closely 

 crowded together. This is not peculiar to flowers alone. 

 The same thing happens in the crowded leaf rosettes of 

 Sempervivinn (Plate XXIV., Fig. 1) and other plants. The 

 floral leaves are, however, not merely crowded on the 

 shortened axis or receptacle, but they are also usually arranged 

 in successive circles, known as whorls, instead of being in a 

 continuous, spiral series. 



Let us now examine the floral leaves, and notice how they 

 are modified for the ultimate purpose of setting seed, which 

 \vill reproduce the plant. Starting from the outside of the 

 flower — in other words, from the base of the floral shoot — we 

 first meet with a group of leaves, the perianth, which have 



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