155 



take on the branches. A hasty glance might give us the impres- 

 sion that the leaves are not produced on the under side of the 

 branches ; but a more careful examination will convince us that 

 there are nearly as many on the under side as on the upper. 

 The leaves are all pointing outward from the branch and as 

 nearly upward as is possible. In other words, the leaves grow 

 toward the light. 



We must not forget to see how long the leaves of the Norway 

 spruce persist and to find out when the leaf-scars disappear. 

 We can find leaves that must surely be six or seven years old 



46. Twig of the common Norway spruce. Half natural size. 

 and sometimes we can find them even older than this. The leaf- 

 scars, too, remain along time. The falling of the leaves is illus- 

 trated in Fig. 46. It shows the extremities of a limb which is 

 eight years old. The part between the tip and A is last season's 

 growth ; between A and B it is two years old ; and beyond B is a 

 part that grew three seasons ago. The section beyond C is six 

 years old ; from C to D is seven years of age. The four years' 

 growth of this limb not shown in the drawing was as densely 

 covered with foliage as is the part shown in the upper figure ; but 

 there are not many leaves between C and D (seven years old) and 

 none on the eight-year-old wood (except those on the branchlets, 

 and these are younger.) 



