538 OUR WOODLAND TREES. 
a free circulation of air around the lower parts of 
the trunks of the Trees in the dense Pine forests 
is prejudicial to the development of side branches. 
They are formed, as in other Trees, at first, but 
gradually decay and fall off as the trunk soars 
upwards. 
The leaves of Pinus sylvestris are needle-shaped 
and rigid in texture, varying from an inch and a 
half to nearly three inches in length. They are 
borne in twos, in scaly sheaths, are concave or 
grooved on one side, and slightly twisted, or waved, 
in appearance. Their colour is a bluish green, 
and this hue, contrasting with the dark red colour 
of the trunk and stems, gives to the Tree a strik- 
ing and impressive appearance. The flowers of the 
Scotch Fir are produced usually in May or June, 
and are succeeded in the female catkins by cones 
of from two to three inches in length, and from an 
inch to nearly an inch and a half in breadth 
at their widest parts. 
Of the value of the red timber of Pinus syl- 
vestris, we have already spoken. It is admir- 
able for every purpose for which Pine wood is 
used; it is comparatively free from knots, and 
