PROCEEDINGS—PERTHSHIRE SOCIETY OF NATURAL SCIENCE. lxiii 
tints we must see them in mass, along the edge of the copse, lit up 
by the winter sun, and relieved by a sprinkling of snow. 
With the gradual approach of spring the vital forces of the tree, 
which have never been altogether inert during the winter, begin to 
re-assert themselves, and very gradually a change comes over the face 
of the woodlands. Long before the last traces of winter have dis¬ 
appeared, however, the alders, hazels, and willows begin to hang out 
their golden-tasselled catkins, giving a promise of colour along the 
margins of watercourses. As spring advances, other of our native 
trees burst into flower, among the earliest being the gean, the bird- 
cherry, and the hawthorn. The first of these makes a glorious mass 
of delicate pink and white, which only lasts for a week or two, and 
then disappears with a shower of petals like a fall of snow. The 
bird-cherry makes a beautiful feature on the edge of a Highland 
copse, with its loose racemes of pure white hanging from the tips of 
the branches. Of our introduced trees, perhaps the most beautiful 
at this season is the larch, the young cones appearing like tips of 
the loveliest coral, and the leaves, when they first come out, being 
a delicate grass green. 
By this time the buds of the deciduous trees are fast swelling and 
bursting as the rising of the invigorated sap through the vessels of 
the tree quickens all its functions into new life. At this stage the 
woodlands present an indescribable variety of delicate tinting, 
running through every shade of golden brown, russet, pink, yellow, 
and pale green, relieved only by the darker green of the pines. 
Perhaps the best place to study this spring tinting is the mixed 
wooding which fringes the upper reaches of the Tay. 
Gradually, as spring merges into summer, the brown and golden 
scales which protected the buds disappear, the leaves expand and 
deepen in colour, and the brown skeleton whose graceful form we 
admired in winter becomes more and more hidden from view, until, 
by midsummer, the monotony of intense green becomes almost 
trying to the eye. This, however, does not apply equally to all trees. 
The ash, for instance, long retains its spring aspect of leafage, and 
never becomes very thickly clothed. The birch, also, with its tiny 
shimmering leaves, always presents a pleasing contrast to the more 
densely covered forest trees. Of the latter, the sycamore, perhaps, 
carries the densest mass of foliage. 
The period of maximum foliage does not last very long, for soon 
Nature exhausts her resources, and the vital forces of the tree begin 
to wane. It is then, when the combined action of the sunshine on 
the chlorophyll of the leaf and of the sap from within have reached 
and passed their maximum, that those mysterious chemical changes 
take place which result in what is the chief glory of our woods, 
namely, their autumn colouring. Here again each species displays 
its own individuality. Take, for instance, the beautiful stretch of 
wooding which fringes the river Braan above and below the bridge 
at Inver. Here the most brilliant points of crimson are presented 
by the fern-like sprays of the mountain ash. The alders and hazels 
show a modest neutral tint of yellowish green. The beeches in the 
