Conifers 
they now extend, for Werchojansk is much colder than 
many places beyond the range of conifers. This seems 
remarkable when these piries inhabit a country which 
is buried in deep snow for months together, but it is 
nevertheless true that pine needles die of drought even 
when the ground is everywhere snow-covered. 
Suppose under these conditions that the sun shines 
out and an icy wind begins to blow, then the snow 
rapidly melts and the leaves at once begin to try and 
form sugar. But where is the water to come from? 
The roots are buried in ground frozen solid for several 
feet downwards, and even the sap in the stem is nothing 
but ice. So it often happens that the needles wither, 
turn brown, and drop off. This happens even to our 
own hardy Scotch pine when there is a day or two of 
brilliant sunshine during a very hard frost. 
It is this danger also that explains some of the most 
remarkable peculiarities of pine needles. The blue- 
green, waxy appearance, the solid fleshy sort of structure, 
and the way in which the breathing pores are sunk 
below the surface, are all at once understood by re- 
membering this danger of drought. 
In other respects conifers show that they are well 
fitted to resist both cold and snow. They store up 
their winter reserve-stores in the form of fat or oil, not 
as starch? This has been compared to the fattening 
up of bears and other hibernating animals, and it is at 
any rate true that the vegetable fatty and oily substances 
are better fitted to resist the effect of hard frost. The 
resinous character of most coniferous trees is also of 
great importance, for wounds caused by a broken branch, 
or some insect which burrows into the wood, are effec- 
tively sealed up. Conifers always possess a root-fungus 
or Mycorhiza, so that they are able, like heather, &c., 
to use peaty soil in which ordinary plants do not thrive. 
As we have already seen elsewhere, they follow on after 
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