Seeds and How They Grow 



505 



of the embryo, but in the seed outside the embryo. Food stored 

 in this way is called endosperm. 



Other parts of the seed are : the micropyle, a tiny opening in 

 the seed through which the pollen grains grow into the ovule, or 

 egg cell, and through which the hypocotyl comes out ; the hilum, 

 a scar which indicates where the seed was attached to the parent 

 plant ; and the integument, the outer covering or seed coat. Often 

 the integument has two layers, the outer being hard or tough and 



plumule. 



plumule-- 

 cotyledons- 



first bud 

 hypocofyf 



'first bud 



^-cotyledons 



THE GROWTH OF THE BEAN SEEDLING 



the inner soft and thin. In such cases the outer layer is called 

 the testa. 



Types of Seeds. The bean and the corn grain are two types 

 of seeds well worth study. The bean is a dicotyledonous seed 

 and the corn grain a monocotyledonous seed. Study of these will 

 show that, while they differ in structure, they carry on the same 

 life processes, effect the same purpose, and serve mankind in the 

 same way. 



