WRAT IS A SMED? 331 



vided with a small flower-pot, or other dish, or even with a 

 oigar-box, and be allowed to have it upon his desk. If the elon- 

 gation 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 (390, 390a), 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. 



LXIV. WHAT IS A SEED? 



406. 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 (377a), and that they 

 contain a miniature plant. This 

 condensed and miniature plant 

 in the seed is called the embryo. 

 The phenomena of fertilization „ „^„ 



^ PiO. 350. 



are too obscure to be clearly 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. 



407. Let us return to the bean. In the pod 

 (Fig. 248), the beans are seen to be attached by 

 short stalks to the edge of each valve. The 



