149 



The white pine. 



In Fig. 38 is shown a white pine branch. Notice that the 

 leaves are borne in bunches or clusters of five. Each bunch of 

 leaves is produced in the axil (or angle) of a minute scale-like 

 body, but this scale cannot usually be found except on the very 

 young growth. It has been worn away or 

 broken from the older growth by the wind 

 and the rain and the other forces of nature. 



Another strange fact should attract our 

 attention. The leaves of the maples and 

 other deciduous trees are borne only on the 

 present season's growth; but this is not 

 the case in the pines, and kindred trees. 

 If we trace back the growth of the past 

 two or three years, we shall find that there 

 are as many leaves on the wood that is two 

 years old as there are on the last season's 

 growth ; and in many cases we can find 

 leaves on the part of the branch that is 

 three years old. This means that the pine 

 leaves or needles are two and sometimes 

 three years old when they fall. The Fig. 

 38 shows the falling of the leaves from the 

 different years' growth. The part of the 

 branch between the tip and A is the last 

 season's growth; between A and B it is two 

 years old ; the part between B and C is 

 three years old. The part that grew four 

 seasons ago — beyond C — has no leaves. 



The different season's growth is not indicated by distinct 

 ''rings" as in the case of deciduous trees (See Leaflet No. 3), 

 but by the branching. Each whorl of branches about a limb 

 represents the end of a season's growth. A young pine tree, or 

 the younger limbs of an old tree, show this character very plainly. 



Do the leaves of the pines and of the other evergreen trees fall 

 at the end of the growing season, as the leaves of most of the 

 deciduous trees do ? Or do they gradually become lifeless and fall 

 at any season, from the force of the wind and other forces of 



39- 



Cone of white pine. It 

 has shed its seeds. Half 

 natural size. 



