324 THE PARTS OF A SEED-PLANT 



a root, and so leading an independent existence. On this view 

 each segment would correspond to an individual animal and 

 its leaf-part and stem-part would be likened to the members 

 of the animal body, such as the trunk and the liml)s. With- 

 out accepting this extreme view of what constitutes an 

 individual plant — a view not in accord with what we have 

 learned about the development of the shoot — it may still be 

 convenient to regard the bodies of the higher plants as built 

 up of segments, much as zoologists regard the bodies of 

 many segmented animals like earth-worms and lobsters as 

 consisting of a series of roughly comparable units; and, 

 similarly, just as the limb of an animal viewed as one of the 

 main divisions of the body or of a segment is called a member, 

 so the main divisions of a plant-segment — the stem, the 

 leaf, and the root — viewed not as organs but merely as parts 

 differing in origin and position, may be conveniently dis- 

 tinguished as members of the plant body. 



But the question at once arises, supposing it to be admitted 

 that the vegetating plant may be roughly likened to a many- 

 storied building, each story being a segment, and the whole 

 supported on a root foundation, can we yet find correspond- 

 ing units of structure in the flower? If the flower is com- 

 posed of segments it is evident that the different members 

 must be more or less disguised. As regards the floral envel- 

 opes we have already seen that their leaf-like nature is so 

 thinly disguised that they are commonly recognized as 

 "leaves of the flower." Indeed, we have only to suppose 

 the internodes of the stem-parts to have remained as short 

 as they were in the bud, while the leaf-parts expanded, to 

 see that so far as origin and relative position are concerned, 

 the floral envelopes are essentially^ like a leaf-rosette. But 

 the stamens and the pistil present greater difficulties. Still, 

 when we come to compare other flowers with those of the 

 flax, we shall find much evidence going to show that even 

 stamens and pistils correspond in large part to leaves. One 

 sort of evidence — not indeed conclusive, but yet significant — 

 is the occurrence now and then of monstrous flowers in which 

 actual green leaves occupy the place of the stamens and pistil, 

 much as if the organs had determined to throw off all dis- 



