CHAPTER VIII 

 SEEDS AND SEEDLINGS 



50. The structure of seeds. On examining the outside of 

 any seed we can usually find a scar that was left when the seed 

 broke away from the little stalk by which it was fastened inside 

 the fruit. Very often we can also find a tiny hole through the 

 seed coat. This hole is called the micropyle. The seed may 

 absorb water through this hole, but it does not seem to be of 

 any importance in the mature seed. (See p. 302 and Fig. 134.) 



The coat of the seed, which sometimes has more than one 

 layer, is apparently a protective covering, although in some 

 species of plants the protection is furnished by the fruit in 

 which the seed is borne. When the coat of a seed is removed, 

 we find the part of the seed that is really important in the life 

 of the plant. In fact, we may say that the^seed contains a 

 young plant. The embryo is really a small, young plant; 

 and we may say that the seed is a young plant (embryo) plus 

 its protective covering. 



51. The embryo. That the embryo is a plant can be seen 

 from a careful comparison with the parts of any ordinary plant. 

 Now, what are the parts of a plant ? Ordinarily we see above 

 the ground only the stem and the leaves, but most of us know 

 that under the ground is the root. In most plants the stem 

 and the root are branching organs ; in some plants the leaves 

 also divide or branch. All of the stem system, together with 

 the leaves, we sometimes call the shoot. So we may say that 

 the plant consists of root and shoot. But sometimes we find 

 flowers on a plant, or fruit. The flower is really a special kind 

 of shoot (see pp. 300 ff .), consisting of a very short stem with many 

 special kinds of leaves crowded closely together, and with 



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