48o NATURE-STUDY 



starch in the green part. Use white-bordered geranium leaf. 

 Emphasize the importance of the leaf as a starch former, 

 the maker of the food for the plant. Without leaves the 

 ordinary plants would starve. Do not take up here the 

 sources of the starch, nor the relation of starch formation 

 to light. Leave this for later year. Discuss the storage 

 of starch for later use in roots, tubers, bulbs, and seeds. 

 In this way we get our starch for food. Show by exper- 

 imental cultures the temperature, light, moisture, and fertil- 

 ity conditions needed by a plant. Much of this can be ap- 

 preciated by the sixth grade children, but care should be 

 taken not to make the matter too scientific. Apply these 

 lessons as far as possible in the school -garden. (Refer- 

 ences: 190, 152, 156, 158, 196, 165, 164, 222, 228, 241, 230, 

 231, 223.) 



Modified leaves : Leaves change to spines — thistle * and 

 cactus;* to cups in pitcher plants *; to tendrils partly or 

 wholly as in sweet pea.* Observe these and refer to the 

 advantages to the plant to have adopted these changes. 

 (152, 154, 156, 14, 161, 193. Pitcher plants — 195, 104, 

 192.) Bulbs * and heads * (cabbage) are also modified 

 arrangements of leaves. They may be compared to great 

 buds. Cut lengthwise and note structure. (See last.) 



Trees: Compare walnut and butternut. Study leaf,- 

 flower, and fruit. Study comparatively the oaks.* Note 

 that there are two forms of boxelders;* the one with stam- 

 inate flowers, the other with pistillate. Refer to the method 

 of pollination — by wind. What other trees are thus polli- 

 nated ? Observe abundant pollen in such trees. Do these 

 trees have large pretty flowers? (Refer to 152, 193, 156, 154, 

 159, etc.) 



