326 



THE FIR TRIBE. 



without injury. When the seeds are thoroughly 

 ripe, but not before, the cones, whether remain- 

 ing attached to the tree or lying on the ground, 

 open spontaneously, and allow the seeds 

 to escape. 



Thus a constant succession of young 

 plants is kept up, a provision which, 

 in the case of this tribe, is the more 

 necessary from the fact that they send 

 up no suckers from the roots, and 

 when cut or blown down they never 

 send up new shoots from the mutilated 

 trunk. Their duration, too, in most 

 instances, is less than that of other 

 forest-trees. 



Seedling Firs are remarkable for 

 being composed of five or six seed- 

 leaves, which in their youngest stage 

 are united at their points by the shell 

 of the seed. When this falls off* they 

 spread, and a bud containing true 

 leaves rises from the centre. 



The geographical range of the Fir-tribe is 

 extensive, but they are most abundant in the 

 temperate parts of the northern hemisphere. 

 Some species are found both in Europe and 

 America, so far north as to border on the 

 regions of perpetual snow ; and others, in central 

 Europe and in Asia, on the Alpine and Hima- 

 layan mountains, where, from their great elevation, 

 the climate is equally cold. Other species occupy 

 the same position in the mountains of America, 

 extending to the height of more than twelve 

 thousand feet, beyond which altitude vegetation 

 entirely ceases. 



