THE BIRCH 5 



shoots, which bear a few leaves, and are enclosed 

 by bud-scales. The pollen-bearing catkins are often 

 nearly two inches long, each of their scales, or 

 " bracts," having two lateral appendages, or " brac- 

 teoles," which protect three flowers, each with two 

 forked stamens. The female catkins are shorter, and 

 are at first erect. In them the two bracteoles cohere 

 with the bract to form a three-lobed scale, which, as 

 we have seen, falls off with the three fruits that are 

 produced from its base, and the form of the side lobes 

 of which distinguishes the sub-species. The little 

 fruits are furnished with a broad membranous wing, 

 which, together with their flattened form, aids in 

 their dispersal by the wind. Their general outline 

 is thus nearly circular, surmounted by two small 

 stvles, an indication of the original two chambers 

 of the ovary, each with its one pendulous ovule, 

 reduced in the fruit stage, by an abortion frequent 

 among trees, to one chamber and one seed. 



The wood of the Birch is diffuse-porous, with 

 minute vessels in groups of as many as eight, with 

 pith-rays so fine as to be indistinguishable by the 

 naked e}^e, and with pith-flecks towards the centre 

 of the stem. Whilst the sapwood is a light 

 yellowish-brown, the heart is slightly tinged with 

 red. Though moderately hard, it is exceptionally 

 porous, and of so even a grain as to be readily turned. 

 . In early times not only did the Birch provide 

 primitive man with his canoe, but it probably roofed 

 his rude shanty, and furnished fibre for his cable, 

 fishing-lines, or other cordage, in districts beyond 

 the northern limit of the Linden. Probably, too, it 



