32 THE BOOK OF NATURE STUDY 



on roots. Country walks will give opportunity for observation 

 of plants and their adaptation to their habitat. 



1. The difference in the shape of tap-roots may be illustrated 

 by a comparison of the carrot, the turnip, and the radish. These 

 should all be drawn. 



2. The fact that roots are storehouses will be evident on 

 examining the' beetroot, the carrot, the turnip, and the spinach. 

 The nature of the food-material stored can be tested by rough- 

 and-ready methods. It is often possible to detect sugar by taste, 

 as in beetroot and carrot ; starch by iodine. 



3. The roots of leguminous plants should be examined for 

 tubercles. Their presence is a sign that these plants are using 

 the free nitrogen of the air. This can be done by digging up 

 clover, which is so often planted for fodder. 



4. The root-systems of different typical plants may be observed 

 by growing germinating seeds of the plants between cocoanut 

 fibre wrapped in porous paper and the side of a glass cylinder. 

 Maize, pea, wheat, sunflower are suitable. 



5. The difference in root-systems, according to the habitat 

 of the plant, may be studied in walks planned for the observation 

 of Nature. Plants growing in dry situations often have long 

 tap-roots. The difference in the firm attachment of the plant 

 in the soil when the root-system is deep, and when it is shallow, 

 is soon seen in the comparative ease with which it is possible to 

 pull up a shallow-rooted plant. 



As far as possible, students should try and make their own 

 observations, and not be content with seeing an experiment per- 

 formed in class ; it is only in this way that it is possible to get to 

 know with first-hand knowledge something of the vital activities 

 of plants. 



