THE STORY OF SEEDS 



255 



The pollen produces the sperms. How are they ever 

 going to get to the eggs? 



Look at the picture. Notice the slender, stem-Hie struc- 

 ture that rises from the ovary. You can find this in nearly 

 every kind of flower. At the very top of this structure 

 there is a rough and usually sticky surface. This is the 

 pollen-catcher. Pollen may blow on it, or fall on it, or 

 be rubbed on it, or be carried to it by insects. But, how- 

 ever it gets there, when it gets 

 there it stops, and it begins 

 to grow. It sends an invis- 

 ible tube down through the 

 stem-like part, and then into 

 the ovary, and then into the 

 ovules themselves. When the 

 conditions are right, there is 

 one pollen- tube for each ovule. 

 These invisible pollen- tubes 

 contain the sperms. Now you can see how the fertili- 

 zation of seed-plants occurs, and now perhaps you can see 

 what a seed really is. 



The fertilized egg, lying there inside the ovule, begins 

 to grow into a new plant. This little plant that is formed 

 inside the seed is called the embryo. At the same time, 

 the outer part of the ovule hardens and forms the tough 

 coat of the seed (see Fig. 97). Between the coat and the 

 embryo, food is stored for the use of the little plant when 

 the seed begins to sprout. If you study botany you will 

 learn more about the various groups of plants and the way 

 they are related to each other. But, whether you ever 

 study botany or not, you should understand something of 

 the relationship between seed-plants and those that do not 



FIG. 97. Section of a seed, show- 

 ing embryo inside, and tough coat 

 outside. After J. M. COULTER. 



