PROBLEM 3 How Do the More Complex Plants 



Reproduce? 



What are seeds? When farmers want 

 oats, wheat, squash, or beans, they plant 

 seeds. It would be interesting, therefore, 

 to find out what is in a seed. We can do 

 this by studying large seeds such as peas, 

 beans, or corn. When we study these 

 seeds, which differ from others only in 

 size or in other unimportant ways, we 

 find that each seed contains an undevel- 

 oped plant. This undeveloped plant is the 



embryo. If you put some soaked seeds 

 into moist sawdust or sand you will see, 

 after some days, that the seed coats have 

 been burst by the growing embryo, 

 which soon develops into a seedling. We 

 speak of this growth as genn'mation of 

 the seed. Exercises i and 2 will help you 

 understand what a seed is. 



How are seeds formed? It took scien- 

 tists many years to discover just how 



Corn 



Bean 



Fig. 385 This oak seedling has burst open the 

 coats (seed and fruit) which covered it. It is 

 growing on the food stored in the seed. (Amer- 

 ican MUSEUM OF NATURAL MISTOKY) 



Fk;. 386 All the tissues within the bean seed 

 coats (below) is part of the evtbryo. hi corn 

 (above) the embryo is buried in a mass of 

 food-storage tisstie {endosperm). 



