70 



HOW PLANTS ARE PROPAGATED. 



nr 



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petals, eight stamens (twice four), and four pistils. So tlie floAver of Trillium (Fi 

 162) is symmetrical; for it consists of three sepals, three petals, six stamens (one 



before each sepal and one before each petal), and 

 a pistil plainly composed of three put together, 

 having three styles or stigmas. Flax affords an- 

 other good illustration of symmetrical flowers (Fig. 

 170) : it has a calyx of five sepals, a corolla of 

 five petals, five stamens, and five styles. In such 

 flowers, and in blossoms generally, the parts alter- 

 nate "vvith each other ; that is, the petals stand be- 

 fore the intervals between the sepals, the stamens, 

 when of the same number, before the intervals be- 

 tween the petals, and so on. 



208. An Uiisymmetrical Flower is one in which 



the different organs or 



sets do not match in 



the number of their 



parts. The flower of 



Anemony, Fig. 1G3, is 



unsymmetrical, having 



many more stamens 



and pistils than it has 



calyx-leaves. And the 



blossom of Larkspur 



(Fig. 171) is unsym- 

 metrical, because, while ^ (r~"~~^^^p^ 



it has five sepals or 

 leaves in the calyx, there are only four petals or co- 

 rolla-leaves, but a great many stamens, and only one, 

 two, or three pistils. The sepals and petals are dis- 

 played separately in Fig. 172; the five pieces marked 

 5 are the sepals; the four marked p are the petals. 



209. A Regular Flower is one in which the parts of each sort are all of the same 

 shape and size. The flowers in Flax (Fig. 170) and in all the examples pre- 

 ceding it are regular. While in Larkspur and Monkshood we have not only an 

 unsymmetrical, but 



