35° 



SCOTCH FIR (PINE). 



can be discerned ; these recurrent intervals will sufficiently account tor 

 the apparent growth ot the branches troni points on a circle drawn 

 round the trunk, though our study ot an earlier stage has shown 

 them actuallv to be produced at points on a spiral. 



In older trees many of the branches die for want of light and 

 air, and their arrangement in clusters is destroyed. Another distinctive 



DIAGRA^r OF THE CHARACTERISTIC 

 CURVES AND ANGLES. 



feature of the tree is the construction of the branches in long slightly 

 curved lines, which break suddenly up or down into sharper curves, 

 often several times repeated, sometimes straightened out, or again bent 

 into a decided angle. Age alone is responsible for these strange 

 deviations, but their cause may be ascertained by a study of the 

 development of the young shoot. It first appears at the extremity 

 of the branch, pointing upwards to the light. During the first season 

 it bears cones and leaves at its apex, and is bent into a downward 

 curve by their unwonted weight. New upright shoots are successively 

 formed, and under the growing burden of its fruitage the bough 

 becomes gradually pendent, though it curves less sharply in its stubborn 



