NOTES AND QUERIES. I07 



Let US now consider how the above facts may bear upon the 

 cultivation of the tree in Scotland. 



The maximum limit of spontaneous growth, which extends to 

 2100 metres in the Pyrenees, is reduced gradually by 900 metres 

 to 1200 metres in the Vosges, where forests of this species were 

 visited by the Society in 1904. It is, of course, a well-known 

 fact that the variations of temperature due to changes of 

 latitude have the effect of raising or lowering the vertical zone 

 of spontaneous growth, and of profitable cultivation ; and as 

 Perthshire is about as far north of the Vosges as that mountain 

 range is north of the Pyrenees, it may not be an unreasonable 

 assumption that, other conditions being equal, the maximum 

 limit of the zone of profitable cultivation might be lowered to 

 300 metres (say 1000 feet); while, at the same time, its 

 minimum limit might be reduced considerably below 650 feet. 



To what extent do our " other conditions " differ from those 

 of the great French silver fir forests ? It seems probable that 

 the essential conditions are at least as favourable here as there, 

 and that in the all-important matter of moisture we have the 

 advantage. In regard to this question, M. Boppe writes 

 {Transactions, Vol. XI. p. 196): "We were struck by the 

 wonderful aptitude of the soil (of Scotland) to forest vegetation, 

 favoured as it is by a regular climate and the constant humidity 

 of the atmosphere." 



If the silver fir were here grown under the conditions most 

 favourable to its development, there is, apparently, no reason 

 why it should not yield a very useful and valuable timber, 

 rendering its cultivation profitable. The necessary conditions 

 would appear to be : — 



1. Zone of Altitude. — Between, say, 300 or 400 and 1000 or 



1200 feet above sea-level. 



2. Aspect. — Northerly, where the young trees would suffer 



less than elsewhere from spring frosts, but where, as on 

 other aspects, they should be raised under "nurses" if 

 necessary. 



3. Density. — The stock should be kept dense at all stages of 



growth, in order to suppress side branches, and to produce 

 long, clean, and straight stems with little taper. 



4. Mixture. — The stock should, preferably, consist of silver fir, 



mixed with beech or with spruce according to local 



