90 FIRST LESSONS WITH PLANTS 



with a small flower-pot, or other dish, or even with a cigar-box, 

 and be allowed to have it upon his desk. If v the elongation of 

 the parts is to be watched very closely, and especially if the root 

 is to be marked in order to observe its method of growth C107, 

 107a), the seeds may be germinated between damp blotting papers. 

 If a dozen or more seeds are started, a record may be kept of the 

 various stages in germination by pressing the plants, as well as 

 by drawing them. 



XVIII. WHAT IS A SEED? 



116. The two most important characteristics of 

 seeds we have already learned, the facts that 

 they are the result of the fertilization of the 

 ovule by a pollen grain, and that they con- 

 tain a miniature plant. This 

 condensed and miniature plant 

 in the seed is called the embryo. 

 The phenomena of fertilization 



FIG. 88. 



are too obscure to be clearly ,. 



J The parts of a bean seed. 



understood, much less to be 



seen, by the beginner ; but it may be said that 



the nucleus of the pollen -grain unites with the 



nucleus of the egg- cell in the embryo -sac, and 

 the result of this union is the embryo. 



117. Let us return to the bean. In the ripe 

 pod the beans are seen to be attached by 



short stalks to the edge of each valve. The 



