NATURE-STUDY LESSONS. 91 



(c) Considering the relation of leaves to sunlight, 

 what is the purpose in this difference of 

 position assumed by the leaves in these two 

 cases ? 



32. Observe the arrangement of the leaves with refer- 

 ence to each other and note how this arrangement is 

 adapted to secure the greatest surface exposure to sun- 

 light. 



33. (a) How do the bases of the leaves compare in 



width with the middle of the leaves and 

 with the apexes ? 

 (i>) Keeping the same arrangement, what would be 

 the effect of the leaves upon one another if 

 the bases were wider than the other parts, 

 as in the lilac ? 



(c) What adaptation is shown in the relative 



arrangement of the leaves of the dandelion ? 



(d) Infer from the leaf-position the direction in 



which the rain-drops and collected dew run 

 from the leaves. 



34. Knowing that one of the functions of the root is to 

 absorb moisture from the soil, infer one of the influences 

 that determine the downward rather than the lateral root 

 extension in the dandelion. 



35. Compare the leaf-position and the direction of 

 root-development in the dandelion with the same in the 

 beet, the turnip and the rhubarb. 



36. Examine a leaf more carefully and determine how 

 the water is assisted in its downward course by the struc- 

 ture of the leaf. 



37. In what different ways is this plant adapted to its 

 environment through its leaves ? 



