90 A NEW ZEALAND NATURALIST'S CALENDAR. 



temperature far below the freezing point of water, the 

 safer it will be for the tissues of the plants, and this is 

 probably one reason why the leaves are discarded before 

 winter. 



Another reason is that were plants to retain their leaves 

 they would carry more or less snow, and if this were moist 

 and fell heavily, as is often the case at the beginning of 

 winter, much damage might result by the branches and 

 stems being torn off or broken down. Looking round our 

 shrubberies and plantations we might think that this 

 statement was inaccurate, in view of the many evergreens 

 which we see there. But it must be remembered that most 

 of our evergreens are not natives of cold climates, but have 

 been gathered together from warmer regions, and often 

 have a hard time of it in a sharp winter. An examination 

 of the plants native to or at least growing wild in Britain 

 shows this. There are in the British Isles about fifty 

 species of indigenous trees and shrubs, exclusive of small 

 forms like heaths, broom, etc. Of these only nine are 

 evergreen Barberry, Holly, Spindle-tree, Arbutus, Privet, 

 Box, Scotch Fir, Juniper, and Yew and their leaves are 

 nearly all of a hard or at least a firm and dry consistence. 

 The other forty-one are deciduous. 



Those coniferous trees which grow in regions Avhere the 

 winter cold is very intense are either very stiff and rigid, 

 and so do not carry snow, or their branches are given off 

 at such an angle with their trunk that they have a down- 

 ward sweep, and so yield to any load of snow which falls on 

 them until they reach such a slope that their burden falls 

 off. The Norway spruce is a familiar example. The only 

 conifer I know of which does not fulfil these conditions is 

 the larch, which drops its leaves at the approach of winter. 

 This adjustment to varying conditions is well seen in two 

 or three familiar genera of trees. Thus the deodar, or 

 cedar of the Himalayas, grows in its native habitats on an 

 elevation of 12,000 feet, and is subject every winter to 

 heavy snowfalls. Its branches and foliage are flexible and 

 yield at once to any weight of snow. The cedar of 

 Lebanon and the allied cedar of the Atlas Mountains grow 



