FORMATION OF THE SEED AND FRUIT 



279 



In the grains, the endosperm is a well-developed, localized, and 

 easily identified structure ; in seeds such as beans, peas, and many 

 nuts, the cotyledons possess 

 the food supply for the devel- 

 oping plant. 



While the embryo and endo- 

 sperm are developing, the ovule 

 coats absorb food from the 

 ducts and develop into seed 

 coats. The ripened ovule and 

 its contents constitute the seed. 

 The ovary ivall grows to accom- 

 modate the developing seeds 

 and forms the fruit. The fruit 

 protects the seeds until they 

 are completely developed. 

 Fruits are frequently adapted 

 to disperse the ripe seeds. 

 These seeds escape from the 

 fruit, and the embryos they con- 

 tain will develop into new 

 plants, if they fall 

 soil of proper temperature. 

 The fruit is a ripened ovary and its contents, together with any 

 other part of the plant that has ripened with it. 



When the bean seed is planted, it absorbs water, and sends a 

 little arched shoot, the hypocotyl,- into the ground. The lower 

 seed or radicle forms the root system. As the upper part or 

 true hypocotyl straightens out, it brings the plumule above the 

 ground. This forms the stem and leaves. The cotyledons feed 

 the tiny plant until its leaves are able to make sufficient food to 

 carry on the life process. The cotyledons may either remain under- 

 groimd or be lifted into the air by the growth of the hypocotyl. 



Given the proper conditions of moisture and 

 warmth, a new plant will develop from the embryo 

 on moist ^^ ^^^ seed. Which of the organs of the plants is 

 developed from the hypocotyl ? 



