94 NATURE STUDY • 



Add a column for temperature in the blackboard record, 

 and constantly call attention to the relationship between 

 the wind and the temperature. By a record of observa- 

 tions, made at different times in the day, establish the 

 fact that, ordinarily, the temperature rises in the morn- 

 ing, and continues to rise until about three in the after- 

 noon, and then as gradually falls. Why is this ? 



After the lessons on temperature, teach the facts about 

 the sun given on p. 64. 



PLANTS 



Obviously the preparation of plants for winter must 

 be the subject for botanical work in November. This 

 preparation goes on all summer, but the results of this 

 labor are more markedly visible in fall. 



Trees : 



Long before the leaves begin to fall, a close observer 

 may find buds containing, in miniature, the whole of 

 next year's growth. These buds attain their full growth 

 shortly before the leaves drop off. 



Many are the devices by which the treasures within 

 are protected. Numerous thick scales and woolly linings 

 serve to keep some from the cold of winter, while a shiny 

 outside, resin or gum, protects them from injury from 

 rain cr melting snow. 



The leaves themselves turn yellow, and the food 

 which they have been making goes into the twigs and 

 branches. The green chlorophyll which did the work 

 becomes disorganized. To this is mainly due the yellow 

 or red color of autumn leaves. 



A new row of cells is formed, cutting across the stalk 

 of the leaf. This causes the fall of the leaf. When the 



