The Science of Plant Growing 



47 



to the Apple, where the sixth leaf comes above the first, after the spiral 

 has passed twice round the shoots. This means that the leaves are 

 separated from one another at an angle of two-fifths the circumference 



Fig. 37. 1, Felted Hairs on Leaf of Edelweiss. 2, Stellate Hairs on the Epiderm of Draba. 



of the stem. These arrangements are intended to distribute the leaves 

 so that all will get a due share of light. This is well shown in the 

 Elm (fig. 38) and the Ivy (fig. 39). 



Fig. 38. Leafy Horizontal Twig of an Elm showing Leaves naturally arranged to catch the light 



Not only are the leaves arranged so as to secure the maximum amount 

 of light, but they are also so placed as to contribute to the nourishment 

 of the roots. In the case of such trees as Apple, Pear, Plum, Cherry, Oak, 



