\66 asvifiw, 



flower is inverted or drooping, so tbat the pollen still tails upon the stigmtf 

 Cas in the Fuschia). In other cases of this kind, where the (lower is not 

 drooping but erect, there is a nectary (a honey store) at the botlom oi ths 

 flower, which attracts insects : these, agitating the stamens as they enter, and 

 receiving a quantity of the pollen on their bodies, necessarily deposit a 

 portion of it on the stigma as they fly out. In many plants, as in rue, bar- 

 berry, rock-rose, pellitory of the wall, kalmia, grass of parnassus, the sta- 

 mens are formed with an elastic spring, by which they thiow the pollen on 

 the stigma, or have a moving power by which they approach the stigma 

 and deposit the pollen upon it. In monoecious plants, the antheriferous 

 flower generally occupy the upper part, so that the pollen falls upon the 

 other flowers. In these, in dioecious, and indeed in all plants, the wind 

 is a leading agent in bringing the pollen (which is a very light powder) to 

 the stigma. In a dioecious plant which grows under water ( Valisneria spiral - 

 is), the (antheriferous flowers become detached, rise to the surface, and float 

 about, while the pistilliferous flower, which retains its connection with the 

 plant, has a spiral stalk, which unfolds and lengthens out so as to elevate 

 the flower above the surface of the water— there the two kinds ot flowers 

 meet, and insects or the wind apply the pollen to the stigma, an operation 

 which does not go on effectively under water. Then the stalk of the pistilli- 

 ferous flower resumes its spiral form and draws the flower under water, there 

 to perfect the seeds. The Urticaria, a plant which grows under water, and 

 has perfect flowers, (par. 3 70), has bladders attached to its roots, which 

 become filled with gaceous matter, so as to cause the plant to ascend to the 

 surface when the pollen is ripe, and effect the application of the pollen in the 

 air. When this is done, the bladders loose their ariel fluid, and the plant 

 again becoming specifically heavier, descends to ripen the seeds. 



" The polen of the stamens, which falls upon the stigma, being conveyed 

 through the style of the ovules in the germen, vivifies them, causes in them 

 a new and more vigorous growth, so that they enlarge and grow into seeds, 

 bodies which are capable of becoming plants similar to those tbat produced 

 them. 



" When the seeds are ripe, the seed-case, or pericarp opens (dehisces) to 

 let them escape. They fall to the ground, and, under the influence of heat, 

 air, and moisture, take root, grow, produce the same kinds of organs, and 

 pass through their various stages of existence in the same way as the plants 

 which produced them. 



" The dehisence of the pericarp is beautifully seen in willow-herb, violet, 

 broom, and many other well-known plants. 



" Most plants produce a considerable number of seeds, and in many cases 

 there is some peculiar construction in the pericarp or seed, by which the 

 seeds are not allowed to fall down and accumulate on the spot where they 

 grew, bat are scattered and conveyed to a distance (disseminated) from the 

 parent plant, In most plants that do not drop their seeds around themselves, 

 the wind is the leading agent in dispersing the seeds, being often assisted 

 by the great lightness of the seed, by some appendage, such as wings or 

 feathers (as in willow-herb, in dandellion, and thistle, and the rest of the 

 syng?nesious tribe) which the wind in wafting the seed to a distance, or by 

 the pericarp dehiscing at the upper part and sides, so that the seeds do not 

 fall out, but are shaken or blown out by the wind. In other cases as in the 

 broom (CystiusV the balsam (Impatiens), the Oxalis, there is a mechanical 

 contrivance in the pericarp or seed, which has the effect of a spring, in pro- 

 jecting the seed when ripe, to a distance from the parent plant. a 



To be continued. 



