NOVEMBER 95 



frosts come, a layer of ice is here formed, which, melt- 

 ing and hence expanding, separates many leaves at one 

 time from the branch. 



These leaves have done much for the trees ; in them 

 have been effected the respiration and the digestion of the 

 plant. But their good work does not end with their 

 death. Decayed leaves (leaf mould) are a very necessary 

 and valuable ingredient of the soil. 



The tree itself is much better off without the leaves, 

 since it is now too cold for them to do any work. Its 

 food material will be more effectively protected in the 

 branches, and it can stand more vigorously against the 

 storms and snows of winter now that all superfluous 

 clothing is removed from it. 



Even the trees which retain their leaves make some 

 preparation for winter. The green chlorophyll retires 

 for protection to the innermost part of their leaves, 

 which, in consequence, lose the vividness of their green. 



Method : 



Let the children compare the green leaves on the tree 

 with those that are turning yellow, and also with those 

 that have fallen to the ground. Take them out to collect 

 the last material, and see that they get freshly fallen 

 leaves as Avell as those which have already begun to 

 decay. 



Let them observe the change in color which precedes 

 and follows the falling. 



What work for the plant is done by the green of the 

 leaf ? What has become of all this food ? Why has 

 the leaf changed in color ? What else has happened ? 

 AVhy do so many leaves fall after a frost ? What good 

 is the leaf after it falls from the tree ? AVliat advantage 



