Seeds dill/ iheir (jcniiiiiation 



7 



Plant broad and narrow beans, Indian corn, water-melon, or 

 pumpkin seeds, and any others which you may have gathered. 



As soon as the bean plant begins to make its appearance 

 above the soil, an examination will reveal two thick leaves 

 placed opposite to one another. Between them there is a 

 small leaf-bud with one leaf folded 

 within another. They are attached to 

 the stem, which extends below the 

 first pair of fleshy leaves and joins the 

 root. It may be difficult to say where 

 the stem ends and the root begins. 

 Now compare a seed which has been 

 soaked in water a few hours. Before 

 removing the seed-coat notice the scar 

 or hilum where the bean was attached 

 to the pod. 



At one end of the hilum is a small hole, the micropyle. 

 The seed-coat comes off easily and the seed splits into two 

 parts, which you will see correspond to the two fleshy leaves. 

 They are called cotyledons. Between these two halves there 



Fig. 



ieed Ijeforc 

 the coat. 



P^IG. 7. — Bean seed with 

 coat removed. 



Fig. 8.- 



-Bean seed with one cotyledon 

 removed. 



lies a siTiall curved body, at one end of which may be seen the 

 two srnall leaves the plumule. The other end, which will 

 make the root, is called the radicle. So a seed contains a 

 whole plant, very small and compact, which will germmate 

 when warmth, moisture, and oxygen from the air are supplied.^ 

 The small plant folded away in the seed is called the embryo. 



' Seeds of some South African plants require light \n addition to these 

 three conditions, although light is usually unnecessary. 



