386 



TREES AND SHRUBS. 



thin scales, leaving the surface orange-coloured, but near the 

 base the scales remain attached for a long time, so that the 

 bark here is thicker, rougher, and darker. The structure of 

 the buds, their mode of expansion, and the growth of the 

 branches, have already been dealt with (Art. 180). 



The stiff needle-like foliage- leaves are borne in pairs, each 

 pair on a short or dwarf shoot. Each leaf is slightly twisted ; 

 the upper side is flat, the lower curved, and the two sharp 

 edges bear small teeth (how can one perceive these without 

 using a lens ?). The leaves live for three or four years, their 

 duration depending on the amount of light they receive. 

 Each dwarf shoot bears about a dozen small scales, forming 



a sort of sheath at the base of 

 the two needles. The whole 

 dwarf shoot is cast off when the 

 leaves are dead, giving the old 

 twigs a rough scarred surface. 



Each year a circle of long 

 shoots is formed, so that the 

 age of the tree (after the first 

 three years of its life) can be 

 told at once from the number 

 of these circles of branches, or 

 their remains if they have 

 broken off. When the end 

 shoot is damaged, one (some- 

 times more) of the side shoots 

 grows out so as to replace it; 

 in fact, one sometimes finds 

 that one of the side buds does not expand along with the 

 others, but remains as an " emergency bud." 



The flowers (May, June) are of very simple structure ; the 

 male and female flowers are on the same tree. The male 

 flowers (Fig. 155) are yellow egg-shaped bodies, about inch 

 long ; they represent dwarf shoots, and are crowded together 

 at the bases of the year's long shoots. Each male flower is in 

 the axil of a scale, and has about four scales at its base ; it 

 consists of a slender axis bearing numerous spirally-arranged 

 stamens. Each stamen has a very short filament and a scale- 

 like anther with a small crest at the free end ; on the lower 

 side are two pollen- sacs which open by longitudinal slits and 



Fig. 155. The Pine, showing Cones. 

 (Sketch made in June.) 



