CHAPTER II 

 PROPAGATION OF PLANTS BY MEANS OF SEEDS 



Nearly all farm, garden, and orchard plants are of the seed- 

 producing type. Other plants that do not produce seeds are rep- 

 resented by mushrooms, mosses, and ferns. These bear spores in- 

 stead of seeds. A true seed contains the embryo of the plant which 

 it is to produce. Spores do not contain plant embryos. 



Why Seeds Are Produced. — There are several reasons for the 

 production of seeds. 



1. Seeds will live over winter better than the plants themselves. 

 Many plants, called annuals, die in the autumn and their kind 

 live over winter only in the seed form. Examples of this group are 

 tomatoes, corn, beans, melons and many other farm and garden 

 plants familiar to all. 



2. Seeds are borne also for the purpose of increasing the num- 

 ber of plants. The number of seeds produced by a single plant is 

 indeed surprising. If we count the number of seeds borne by one 

 strawberry and multiply that by the number of berries on the 

 plant in a season, we will find the product running up into many 

 thousands. Similar results will be found with nearly all plants. 

 Take the tomato, squash, watermelon, cucumber, blackberry and 

 currant as examples. 



3. By bearing seeds which are easily distributed, plants provide 

 for their spread over extended areas. With many kinds of seeds 

 there are edible portions, as berries and other fruits and vege- 

 tables. The edible portion induces animals to carry them away 

 for food and thus spread the seeds. Some seeds, as carrots, par- 

 snips, lettuce and others, are carried by the wind or will float on 

 water to distant places. 



How Seeds Are Produced.— Flowers of some kind must always 

 precede the bearing of seeds. In other words, flowers produce the 

 seeds. The essential parts of the flower are the stamens and pistil. 

 The seeds are borne by the pistil as a result of the pollen growth 

 after reaching the pistil. (Fig. 6.) 



Other parts of the flower are the more or less leafy growth 

 around the stamens and pistil. These are the petals and sepals and 

 are not found in all flowers. They may serve to protect the essen- 

 tial parts or to attract insects. 

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