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«B 



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66 



HOW TLANTS ARE PROPAGATED. 



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loaves run into corolla-leaves, and the inner corolla-leaves change gradually into 



stamens, — showing that even stamens answer to leaves. 



198'. How a stamen answers to a leaf, according to the botanist's idea, Fig. 



158 is intended to show. The filament or stalk of the stamen answers to the 



footstalk of a leaf ; and the anther answers to the blade. The lower part of the 



ligure represents a short lilament, bearing an anther which 



has its upper half cut away ; and the sunniiit of a leaf is 



placed above it. Fig. 159 is the whole stamen of a liily 



put l)eside it for coui[)arison. If the whole anther corre- 

 sponds with the blaiU; of a li'af, then its two cells, or 



li.'dves, answer to the halves of the blade, one on each side 



of the midrib ; tiie continuation of the filament, which con- 

 nects tlie two cells (called the roimccfirr'), answers to the 



midrib ; and the anther generally opens along what 



answer to the margins of a leaf. 



199. It is easy to see how a simple pistil answers to a 



leaf. A simple pistil, lik*^ one of tliose of the Stonecrop 



(Fig. 154, 156) is regarded by the botanist as if it were 



made by the folding up inwards of the ))lade of a leaf 



(that is, of what would have been a leaf on any brancii of the common kind), so 



that the margins come together and join, making a hollow closed bag, which is the 

 ovary ; a tapering summit forms the style, and some part of the 

 margins of the leaf in this, destitute of skin, becomes the 

 stigma. To understand this better, compare Fig. 160, repre- 

 senting a leaf rolled up in this way, witii Fig. 156, and with 

 Fig. 16 r, which are [»istils, cut in two, that the interior of the 

 ovary may be seen. It is here ])lain tliat the ovules or seeds 

 are attached to what answers to the united margins of the 

 leaf. The particular part or line, or whatever it^may be, that 

 the ovul(>s or seeds are attached to, is called the Plwcjita. 



200. Varieties or Sorts of Flowers. Now that we have learned 

 how greatly roots, stems, and leaves vary in their forms and 



appearances, we should expect flowers to exhibit great variety in difl'erent species. 



In fact, each class and each family of plants has its flowers upon a ])Uin of its 



own. But if students understand the tjcmcml plan of jfoircrs, as seen in the 



riiui of a 8taiiicn. 



Plan of Pistil. 



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