The flora of Britain has been divided into four classes, each adapted to special climatic conditions: (1) alpine; (2) sub-alpine; (3) lowland; (4) maritime.

When in far off days the ice of the Ice Age was disappearing from Europe, Britain seems twice to have been connected with the Continent by a land bridge. Across this the vegetation of the Continent followed the retreating ice. First came alpine forms, then sub-alpine, next lowland, and finally maritime. The first two classes readily obtained a footing in Britain, but while the two last were still crossing the land bridge became submerged. At the next upheaval these forms effected a crossing, and a severe struggle for existence took place between them and their predecessors. The result was that the alpine and sub-alpine species were forced into higher altitudes. Before every species had crossed, the land bridge was again submerged. The general trend of the advancing species was towards the north-west. Consequently we find that the southern and eastern portions of Britain have a greater variety of species than the north and west; and for the same reason Ireland is poorer in species than Britain.

In Forfarshire all the four classes are well represented, and few counties, if any, surpass it in the richness and variety of its flora. This is chiefly owing to its great diversity both of elevation and of soil. In the long coastline many variations in soil conditions are found—the muddy estuaries of the Tay and the South Esk, the stony beach, sand dunes and links at Barry, Carnoustie, Elliot and Montrose, and the cliffs from Arbroath to Montrose. Behind this and in front of the Sidlaws we have a lowland region, which is largely defaced by cultivation or laid out in towns and hamlets, but there are still some patches of natural vegetation in such places as the Den of Mains and the Birkhill Feus. The Sidlaw range furnishes admirable conditions for the growth of sub-alpine varieties. Behind this again is the long stretch of Strathmore, a second lowland region also largely cultivated, but intersected with wooded dens, and traversed by numerous streams whose sylvan banks provide special local soil conditions adapted to the growth of plants requiring shade and moisture. Behind Strathmore the ground rises gradually until it reaches an altitude of over 2000 feet—sufficiently high for alpine plants to grow.

Many very beautiful specimens of seaweeds or algae may be collected at low tide along the coast, especially on the beach at the foot of the cliffs. The transition from salt water to fresh water mud-plants may be studied at Invergowrie. The formation of firm soil from loose sand by the binding action of the roots and underground stems of the sea couch grass [Agropyron junceum) and the sea sedge (Carex arenaria) is in evidence at Barry. An interesting feature in plant life which is abundantly illustrated in Forfarshire is the similarity in structure between the maritime cliff plants and the mountain plants, several species being found growing on the cliffs and again in the mountain solitudes, but nowhere between.

The influence of man has come to be regarded as one of the conditions affecting plant associations, and is classed along with climate and soil. The cultivated land of the lowland area is divided into two regions—an upper and a lower—according as wheat is grown or not. The lower region is the region of wheat. The area of Strathmore presents a great variety of woodland, partly cultivated, partly natural. In the estates of Cortachy and Glamis, for example, we get specimens of cultivated woodland consisting for the most part of deciduous trees. Oak-woods clothe the river banks in the lower regions, and higher up the shimmering birches enhance the valleys with their sylvan beauty, as for example in Glen Prosen, Glen Clova, and Glen Esk. Large tracts of Scots pine are found scattered over the county, notably at Montreathmont Moor—remains of the extensive forests that formerly clothed Forfarshire. At considerable elevations on the moorland the larch is fairly conspicuous. The beech, the sycamore, the lime, and the horse and Spanish chestnuts are common, but are not indigenous as are the oak, the ash, the elm, the rowan, the hazel, and the alder.

The vegetation of the Sidlaws consists of sub-alpine plants ; heather being dominant on the basalt and sandstone soils, for example, on Craigowl and Auchterhouse Hill, and grasses on andesitic soils, where whin and bracken are also plentiful. Amongst the heather areas there is a marked absence, as a rule, of peat-bogs ; and on the grass-covered hills it has been noticed that the grasses are coarser and stronger on the north side of the hill than on the southern.

It is, however, the mountain fastnesses, and high table-lands on the northern and north-western borders of the county that are of special importance to the botanist. There we find typical alpine vegetation, with its low growth, small leaves of a fleshy or hairy nature, and wiry stems. The commonest specimens are ordinary ling, various heaths, blaeberry, cowberry, crowberry. Another mountain-dweller is Rubus chamremorus, the cloudberry or avron. The alpine lady’s mantle (Alchemilla alpind)

frequently forms a green carpet. Five different species of saxifrage, and fifty species of Saiix, chiefly alpine, occur in the county. The peat-bogs are enlivened by brightly coloured mosses, and red glistening sundews; and occasionally the white petals of the Grass of Parnassus spread themselves out in unsullied purity above the black marsh.

The rarities of the county are the snowy gentian (Gentiana nivalis) which is found in the Caenlochan district, the only other recorded locality in Britain being Ben Lawers. The same district is the home of such rare ferns as the holly fern (Polystichum lonchitis), green spleenwort (Jsp/enium viride), and Polypodium alpestre. The mountain brittle bladder fern (Cystopteris montand) is very rare, but has been found in Glen Caenlochan. Polypodium flexile has been met with in Glen Prosen, and with the exception of Ben Alder this is its only known British haunt. Two rare grasses, the alpine fox-tail grass Hopecurus alpinus) and the alpine cat’s-tail grass (Phleum alpinum), are found on the banks of the Feula burn. The red alpine campion (Lychnus alpind) grows on Little Culrannoch, a hill northward from the head of Glen

Doll. So far as is known this plant occurs nowhere else in Scotland, but a similar plant has been met with on the crags of Helvellyn. In a ravine on the south side of Glen Doll is found the blue alpine sow thistle (Mulgedium alpinum)—a very rare species growing also on Caenlochan and on Lochnagar. Glen Doll yields two other rare treasures—Oxytropis campestris, a small vetch with no other habitat in Britain; and the alpine milk vetch [Astragalus alpinus), found only here and on the Braemar hills.

Mosses and ferns are well represented in Forfarshire, indeed this county has a greater number of species of mosses than any other county in Great Britain, Perthshire alone excepted. Most of the common ferns abound; and besides the rare forms already mentioned, the filmy fern (’Hymenophyllum Wtlsoni) is got at the Reekie Linn, and on the Caenlochan mountains, while the moonwort is abundant on the Links of Barry, and is found in various other localities. The adder’s tongue (Opbioglossum vulga-tum) is said to occur on Barry Links, but is rare. The royal fern (Osrnunda regalis) has been found at Arbroath, Montrose and Kinnaird.

It was not only a fresh flora but also a fresh fauna that Britain received after the ice sheet disappeared ; with this important difference, however, that forms which could fly or swim were not checked by the submergence of the land.

Forfarshire possesses the common wild creatures of Britain. Rabbits and hares are plentiful. In winter and early spring the white hare is a common sight on the mountains and moors. These mountain hares belong to a different species from the lowland hares. This species, which turns more or less white in winter, is found throughout the palaearctic region along with arctic plants, and its presence, often in isolated positions, is regarded as one of the proofs of a former glacial epoch.

Another inhabitant of the mountains and moorlands is the red deer. Large herds of these noble and beautiful animals roam over the hills, but unless taken by surprise it is very difficult to see them at close quarters. Roedeer are native but fallow deer have been introduced. Badgers are gradually dying out. Stoats are abundant. Weasels, moles, hedgehogs, and squirrels are common. Mice and voles and the grey rat are so abundant as to have become a pest in some places. The grey rat has almost extirpated the black, a few specimens of which, however, yet remain.

On account of the variety of environment, there is scope for mountain birds, for sea birds and for cliff birds, while the dens and woods of the rural districts are alive with countless varieties of our native songsters—blackbirds, thrushes, finches, linnets, buntings, wrens, larks, titmice, stonechats, whinchats, pipits, etc. The long-eared owl, the brown, the white, and probably the short-eared, are native, while three varieties of swallows along with the swift are summer visitors. From the verdurous gloom of the spring-woods, one often hears the clear call of the cuckoo and the cooing of the wood-pigeon. Rooks and jackdaws are very numerous at all seasons, and even the magpie has been seen, although rarely. Corncrakes, partridges and pheasants are common in the fields. The capercailzie is found in some places, and on high hills the ptarmigan. The curlew, plover, grouse and snipe are common. Higher on the mountains bird preys on bird ; the eagle barks from his lonely eyrie, the hawk circles above his intended prey, and the sparrow-hawk pursues his victim to death. Besides these we may see the buzzard, the kestrel, and occasionally the peregrine falcon.

Aquatic birds are numerous at the mouth of the Tay, on the links, sands, and cliffs. Many of them are winter migrants, such as the scaup, pintail, and widgeon, the blackheaded gull, and others. The tern or sea swallow, a beaut'ful bird which skims over the surface of the water with very rapid flight, is a summer migrant, whilst the arctic tern comes in autumn. Along the cliffs and on the rocks at sea the gannet or solan goose appears in spring and autumn. Vast colonies of gulls—common, blackbacked, kittiwake and skua—razorbills, puffins, guillemots and ducks of diverse kinds make the whole coast-line resonant with bird life, while the storm-petrel warns the fisherman of a coming tempest. The gulls do not confine themselves to the coast but fly far inland ; and the blackheaded gull breeds on inland lakes and marshes. The hooded and carrion crow are more common near the coast than inland.

The marine fauna of Angus is that of the east coast in general. Seals are plentiful in the Tay estuary and can be seen at low tide basking in the sunshine on the sand banks. Whales also have repeatedly visited the Tay, and on more than one occasion have been attacked in the river at Dundee. The well-known Dundee whale was of the humpbacked species (Megaptera longimand). It was pursued and wounded at the mouth of the Tay, and was subsequently found dead off the coast of Kincardine. Its skeleton is preserved in the museum in Dundee.