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 w^ould be likened to the members 

 of the animal body, such as the trunk and the limbs. With- 

 out accepting this extreme view of what constitutes an 

 individual plant — a view not in accord with wdiat 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 lol)sters 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 bod}' or of a segment is called a member, 

 so the main divisions of a ])lant-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 rouglily likened to a many- 

 stori(>d 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, w(> shall find much evid(nice going to show that even 

 stamens and pistils correspond in large part to leaves. (Ine 

 sort of evidenc(> — not indeed concIusi\-e, Init yet significant — 

 is the occurrence now and then of m()nstr(jus flowers in ^^'hich 

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

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



