TREE FORMS IN WINTER 245 



sparse ; and the fine and slender sprays readily distinguish it 

 from other trees of generally similar growth. The bark of 

 mature specimens is marked with narrow and shallow vertical 

 furrows ; and it is one of the most lichenous of trees, the 

 trunk and main limbs being often as heavy as an old apple 

 or hawthorn tree. 



Alders are very different, and make a great contrast with 

 willows by many winter streams. They are trees of very 

 various growth ; but the comparative density of the fine, 

 crisped twigs and the abundance of little black seed-cones 

 clinging to them make the alder the blackest of all deciduous 

 trees in winter. These little brittle cones are the female cat- 

 kins of the previous summer ; they cling to the tree after 

 their scales have parted and set the seed free. Winter 

 parties of redpolls, as well as linnets and several kinds of tit- 

 mice, are often seen searching among them on the twigs, 

 probably for small insects that creep between the open scales, 

 as well as for lingering seeds. Most small alders, and some 

 large ones especially when growing close together have a 

 tall, straight stem, and stiff and comparatively slender hori- 

 zontal branches. The tree has then rather a weak and unin- 

 teresting appearance. But it is curious that many old alders 

 assume a very different growth, and become gnarled of trunk, 

 broad of head, and warped and twisted of bough. Alders of 

 this handsome type are generally found growing in wet 

 meadows or trickling hillside pastures ; but fine specimens are 

 sometimes found by streams. Young trees have smooth grey 

 bark ; but as they grow older it becomes lightly furrowed in 

 an irregular network, and is rather scaly. Most old specimens 

 are well covered with grey lichen. 



The birch's graceful lines make it easy to recognise in 

 any group of bare winter trees. Though free-growing, often 

 with two or more main stems, it is always beautifully pro- 



