MANUAL OF NATURE STUDY. 121 



etc., are called exalbuminous, because they have no 

 food supply outside of the embryo. 



To which class of seed does wheat belong? 

 Why? Maple? Hazlenut? Buckwheat? Peach? 

 Apple? Beechnut? It will be a good exercise to 

 let the children germinate a great many seeds and 

 classify them. 



{b.) Nature provides protection for the matured 

 seeds. As soaking over night in water will facili- 

 tate the study of protective coverings, — prepare 

 beans, com, peas and other seeds in that way, and 

 begin the observation. Pull off the coverings and 

 try to find an outer, hard covering and an inner 

 mucilaginous membrane. Compare the soaked 

 coverings with those that have not been soaked. 

 Is the covering a good protection against insects? 

 Against changes of temperature ? Against moist- 

 ure? Scrape off the covering of five dry beans. 

 Place these five naked beans, with as many covered 

 ones, in a pan of water. In a few hours examine 

 them, and note difference in the result of the ex- 

 periment. 



How do you account for the difference ? While 

 the outer coat of the seed is almost impervious to 

 water, still, if no water could enter the embryp, no 

 growth could take place. So nature provides one 

 very small entrance to the inner portion of the 

 seed. See if the children can find it, 



