36 ELEMENTARY BIOLOGY 



parent plant. How the parent plant makes its food we shall learn 

 in the lessons on food-making (see p. 53). 



Another point of interest in regard to the food in the seed is that 

 of its availability for human use. This will be discussed later (see 

 Chapter XXII). 



53. Seedlings. If we examine a few seeds that have been 

 planted two or three days, we may see that the hypocotyl has 

 emerged and is assuming the appearance of a root. At the 

 other end of the embryo we may see the unfolding epicotyl. 

 If we examine different stages of peas, squash, oats, corn, bean, 

 and so on, we shall be able to see a great variety of methods 

 by which the young plant crawls out of its covering and 

 establishes itself in the soil (Fig. 8). 



Large seeds, containing a large amount of reserve food, are 

 apparently at an advantage, since they may develop more root 

 and more shoot before they are overtaken by the necessity of 

 providing themselves with food. We should therefore expect 

 that plants with large seeds would be, on the whole, more 

 successful in establishing themselves in a new territory than 

 plants with small seeds. We shall find, however, that the best 

 spreaders in the plant world are those with rather small seeds. 

 The speedy and secure establishment of the individual plant 

 is of great advantage, but even more important is it that 

 seeds be well scattered. And in this respect the small-seed 

 plants with very numerous seeds have a decided advantage. 



