112 MANOAI, OF NATURE STUDY. 



tlie sap is done visiting the leaf or when it brings 

 away the last load, the gate to the foot-stalk is 

 forever closed and the leaf is ready to fall. If frost 

 should come and find the gate open a raw place 

 would be left where the leaf joined the branch, out 

 of which sap would flow, and thus lose part of the 

 winter's food; but the plant seems to understand 

 the situation, hence the closing of the gate or seal- 

 ing over the place for protection. Why do leaves 

 fall after a heavy frost? Are leaves of any benefit 

 after they have fallen? How? What is the form 

 of the food as stored in the bud for the winter? 

 Starch. What change is brought about in the 

 starch when the bud begins to swell in spring 

 time? Sugar. Why is it necessary to change 

 form? So that the sap can dissolve and use it. 

 See lesson on saliva in fourth grade. 



The purpose of the bud is to furnish winter 

 quarters for plant or flowers or both. The buds on 

 the tree are a community of stem germs (baby 

 plants) . 



Compare cocoons of caterpillars with the hiber- 

 nation of Johnny Jump Up or Spring Beauty. 

 Where is the store of food in each case? Where 

 in the tuber? Compare with hibernation of ani- 

 mals, such as frogs, snakes, earth worms, etc., 

 with the migration of birds. 



All nature acts upon one common plan, varying 



