PINETUM BRITANNICUM. 
io 
than in that above it, and their fruit is ripe a month later, making a difference of two months. Thus, in 
Dr Hooker’s lowest zone (8000 to 9000 feet) Rhododendron argenteum flowers in April, and has not its 
fruit ripe until December, thus taking nine months to ripen its fruit. In the second zone (11,000 to 12,000 
feet), R. campanulatum flowers in May and fruits in November, thus taking seven months to ripen its fruit. 
In the third zone (13,000 to 14,000 feet), R. anthopogon flowers in June and fruits in October, thus 
taking five months to ripen its fruit. In the fourth zone (16,000 to 18,000 feet), R. nivale, the curious little 
species, which probably attains a loftier elevation than any other plant in the world, flowers in July and 
fruits in September, thus taking three months to ripen its fruit. And the necessity for some arrangement 
of this sort is obvious. If R. nivale were to take as long to ripen its seed as R. argentezim , the winter 
would be upon it before it had well begun to think about it. A similar rapidity in the ripening of the 
seeds also takes place in the arctic regions. 
We have thus the same phenomenon occurring as the degrees of latitude and zones of elevation 
increase, and we must look for its origin in some common cause. De Candolle’s hypothesis, that the 
longer duration of light which characterizes more northerly regions may be the cause to which the distri¬ 
bution of the species (another of the common phenomena) is due, will not answer, for it is plain that the 
long duration of light in the summer which applies to Lapland does not to the Himmalayas. Some other 
cause must therefore be sought for to explain the phenomenon. Doubtless more than one element com¬ 
bines to produce it, but that summer heat is a much more important element than winter cold— i.e., want 
of heat in winter—is abundantly proved. 
There are other points relating to the present distribution of the Spruce which require explanation. 
M. De Candolle also considers these. He satisfactorily shews that the degree of cold has nothing to do 
with its absence from Britain, Denmark, and the eastern plains of Germany, for greater cold than occurs 
there is habitual in the north of Sweden, where it thrives. Neither can humidity be the reason, for Bergen 
and other localities receive more rain than the eastern coast of England. Level ground, where the water 
stagnates for a part of the year, does not agree with the species; and, according to De Candolle, that is 
the reason perhaps which excludes it from the great plains of the north-west of Germany and from Den¬ 
mark, and which at the same time accounts for its living on the slopes of the mountains of Norway, where, 
although there is plenty of water, it is not stagnant. “In resumed says he, “ the cold of the winter excludes 
the Abies excelsa from the north of Russia and of Sweden, the want of heat from northern Norway, but it 
is not an aCtual physical cause which excludes it from the British Islands: it is antient cause, or an aggre¬ 
gate of antient causes, mounting back perhaps to an epoch anterior to the presence of man in Europe.” 
(De Candolle, op. cit ;, p. 194.) 
The causes suggested by M. De Candolle combined with others may have assisted in producing its 
present partial distribution; but they cannot be regarded as furnishing in themselves a sufficient explana¬ 
tion, because, as in Britain, it grows perfectly well in Denmark, Netherlands, and north-west Germany 
wherever it has been planted, which it sometimes has been in great quantities. 
History. —The Spruce Fir is frequently mentioned by antient authors. Virgil speaks of it, with 
allusions to its height and sombre colouring. Pliny mentions it as used in the funeral ceremonies of the 
Romans, and specifies the resin as scarcely distinguishable from incense. 
It is assumed to have been introduced into Britain before 1548, because Turner includes it in his 
“ Names of Herbes; ” and both Gerard and Parkinson speak of its being found in great quantities in 
different parts of the island ; and that they mean the Spruce is plain from the figures they give, which 
are very fair representations of it. At whatever period it may have been introduced, it has been for long 
a favourite tree with planters. Consequently many fine specimens are to be found in Britain. 
Doubtless, it was not long after its introduction into England that it found its way into Scotland; 
but the first aCtual notice which we can find of its having been planted there is a statement in Dr Walker’s 
Essays that it had been planted at Inveraray in 1682. It was not, however, until the beginning of the 
present 
