98 LIFE : OUTLINES OF GENERAL BIOLOGY 



bars of a cage ; and although often no thicker than the little finger, 

 they make human progress diflficult and slow." 



The picture of the northern forest is in very sombre colours. So 

 crowded are the trees that it may be dark on a summer day; the 

 undergrowth is often limited to berry-bearing plants like blaeberries, 

 or to bog-moss and lichen; sometimes there is nothing but a deep 

 carpet of needle-like leaves. The branches are hoary with lichens, 

 and the trees die of senescence while young in years. There is an 

 all-pervading odour of mouldiness. Except when the summer-visiting 

 birds are in possession, there is a depressing silence. Sometimes 

 everything seems asleep except the mosquitoes. A belt of monotony 

 stretches round the world. 



Relieving the gloom in summer are the birds which batten on the 

 mosquitoes, while others linger long enough to get some of the 

 berries. Miss Haviland has a beautiful touch in picturing the forest 

 birds at dawn, perched on the tops of the trees, waiting for the 

 light. An ousel, far to eastward, begins to pipe faintly, and the good 

 news spreads through the woods, until every tree is a fountain of 

 song. "It seems as if the great wooded shoulder of the earth, rolling 

 eastwards into the sunrise, awakes one songster after another, until 

 Asia and Europe, from Pacific to Atlantic, are linked together by 

 a chain of thrushes' music." 



Among the characteristic forest birds may be mentioned the 

 crossbill, whose beak becomes twisted in early life so as to form a 

 very effective instrument for splitting fir-cones; the attractive 

 waxwing with the quaint red tips to some of its feathers; the wood- 

 peckers who hammer for tunnelling grubs on the decaying stems, 

 the handsome mealy redpolls and scarlet grosbeaks and bluethroats, 

 the vocal thrushes, including the fieldfare and the redwing, which 

 come to us in winter. Then there are big game-birds like capercailzie, 

 blackcock, and the wood-grouse that puts on horny snowshoes in 

 the winter. In swampy places and on the river banks there are 

 sandpipers, redshanks, woodcock, goldeneyes, and bleating snipe. 

 While the clouds of mosquitoes and midges may make the explorer's 

 life a purgatory, it must be remembered, as a theoretical ointment, 

 that the flies are re-incarnated as birds. Perhaps most of the forest 

 birds are seed-eaters, but in the swampy regions there are many 

 illustrations of insects becoming flying fowl — say, wagtails by day 

 and goatsuckers by night. 



Another link in the nutritive chain is represented by the birds of 

 prey, such as the diurnal falcons and buzzards, and by the owls 

 softly flying in the darkness, which extends in the depth of the forest 

 into what should be daylight hours. So we must correct the impres- 

 sion of moribund monotony by noticing the abundance of bird-life 

 in the summer at least; and the same is true of the mammals to 

 which the forest gives shelter. Brehm gives us vivid pictures of the 



