26 NATURE STUDY 



The Structure of the Seed- 



For making out the parts of the seed make use both of dry 

 seeds and of those that have been soaked in water for some hours. 

 It is best to begin with the larger forms such as beans, peas, 01 

 pumpkin seeds. 



Have the pupils see that the seed is a small plant ready to 

 grow, but wrapped up tightly in a covering. The covering has 

 a small opening at one point. The contained plant can be clearly 

 seen to have a stem bearing leaves, and a point that is the be- 

 ginning of the root. The leaves are (in the bean, pea or pump- 

 kin) .first two large thick white leaves filling the main part of the 

 covering, and then the pair of minute ones which are to be the 

 first pair above the seed leaves. Grains of corn and wheat or a 

 pine seed will show a different arrangement of the seed leaves, 

 the first having only one, the last having five. The seed contains 

 stored up nutrition. Often, as in the bean, this nutrition is stored 

 in the thick seed leaves, but in others as in the morning glory it 

 is deposited around the seed leaves. 



The parts of the seed as known in botany are, as illustrated 

 in the bean, for example: The covering, the seed coats; the two 

 thick seed leaves, the cotyledons; the small stem, the caulicle; the 

 part above the cotyledons bearing the minute leaves, the plumule, 

 the point at the opposite end of the caulicle is the root point. 

 The whole minute plant as it lies in the seed is called the embryo. 



Have the pupils hunt out the seed leaves in many forms of 

 seeds, including some in which they are not so evident as in the 

 bean and squash, such for example, as the acorn, walnut, pecan, 

 chestnut, buckeye, wild cucumber. The germination of each of 

 these nuts is very interesting. The methods used by the buck- 

 eye and wild cucumber of this coast are apparently so widely dif- 

 ferent from those of the squash and bean that they present quite 

 attractive puzzles. Who in the schools this winter will solve 

 them? 



