Natural History in the Highlands and Islands

South of Loch Broom, the Torridonian hills are more thickly grouped and reach their highest peaks. Their spiry form and the high corries facing to the east are distinctive. The quality of herbage is generally poor and the terraces formed in the lower reaches of the Torridonian hold up the heavy rainfall so that it is often quite impossible to get about dryshod. How different is the nature of the ground from those smooth dry slopes of glacial sand and gravel which are such a marked feature of the Central Highlands! The differences brought about in the vegetational complex have not been sufficiently stressed by plant ecologists in the past. The ground has not been well walked through and explored as yet.

There are two high hills of the Torridonian which have north-eastern corries quite the most magnificent of their kind and few who have seen them both can decide which is the better. This in itself should show how similar are such groups of hills and the forces which moulded them. I allude to An Teallach of Dundonnell (Plate IIIb and Plate 4a), 3,485 feet, and Beinn Eighe, 3,456 feet, between Kinlochewe and Loch Torridon. Each of these hills has three corries facing NNW. to NE. Coire Mhic Fearchair is the most westerly of the corries of Beinn Eighe, and the Toll Lochan corrie of An Teallach is the easterly one of the range. Some of the buttresses in Coire Mhic Fearchair are exceptionally fine and the corrie makes an almost perfect horseshoe, but for myself I think I prefer the Toll Lochan corrie, for the cliff face at the head of the lochan is of greater depth and of superb architecture, nearly 1,800 feet of it.

Between An Teallach and another corried Torridonian peak, Beinn Dearg Mor, 2,934 feet, is the broad amphitheatre known as Strath na Sheallag, at the head of Loch na Sheallag, from which the Gruinard River runs. This strath is beloved of the deer, and though so remote it draws cattle, sheep and ponies to it from far away. Just as An Teallach has Beinn Dearg Mor as an outlier, so has Beinn Eighe her Beinn Dearg, 2,995 feet, almost a replica of its cousin of Strath na Sheallag. Liathach, 3,456 feet, Beinn Alligin, 3,232 feet, and Slioch, 3,217 feet, these are just three more of these splendid Torridonian peaks—clear of peat from 1,750 feet upwards and often topped with a white cap of quartzite boulders. The sudden change from wet peat-laden terraces to the upper slopes of bare rock, or thin covering of brash and alpine vegetation, results in a sharp snow line in winter which gives these hills a special seasonal beauty. This sudden cessation of the peat immediately allows a different flora, one of plants which can withstand droughts and sudden changes of humidity, and which prefer sweeter conditions than are possible on peat. Here and there among the alpine poa grass and viviparous sheep’s fescue are straggling plants of dwarf juniper, clinging close to the rock. Sea pink and thyme are also to be found on the gravel. Eagle, peregrine falcon and wild cat abound in this country, and as it is all deer forest and not grouse moors of any consequence, the eagle is allowed more sanctuary than it has been given farther south and east.

The glens of the Torridonian area of the North are often well wooded. They have been owned by people with a fair (or perhaps unfair!) measure of worldly riches, who have been able to spend a good deal of money on planting for amenity. Take Dundonnell for example, at the head of Little Loch Broom: the loch side is bare of trees and is given up to crofting townships, but soon after the head of the loch is reached one is into a fine wooded glen. There are a few hundred acres of Scots pine of greatly varying density stretching up the southern side to an altitude of 1,000 feet. There are alders, oaks, rowans, and hazels along the river bank, and some hundreds of acres of birch at the head of the glen reaching up to 1,500 feet. But all round the cultivated strath and the house which was built in 1769 there are signs of planting for beauty: limes, many fine beeches, sycamores, ashes, elms, oaks, chestnuts and big old geans; and until a few years ago there were many acres of fine larches on the north side. The wild life of such a glen is obviously profuse and varied. We have these men of a past age to thank for planting that which we now enjoy, just as we may blame those of a century earlier who were denuding the Highlands of timber.

Loch Maree is another place where there are some very fine woods, but here the sub-arctic quality of the northern zone is being lost and replaced by the complex of sub-alpine vegetation. Near where the Ewe River from Loch Maree goes into the sea in Loch Ewe there is a famous garden which grows a great variety of rhododendrons and azaleas and many sub-tropical plants and plants from Oceania. This is just another facet of the Highland paradox, the garden at Inverewe lying between the stark precipices of Ben Airidh Charr and the bare windswept slabs of Greenstone Point where the sea is never still. And if I may add one more touch of paradox, I saw a kingfisher on the rocks at Greenstone Point at the edge of the tide, one September day.

CHAPTER 3 (#ulink_31808313-a35d-5317-a253-4380d442e1aa)

RELIEF AND SCENERY (continued)

THE WESTERN HIGHLANDS OR ATLANTIC ZONE

SOUTH of Skye the coasts of the West Highlands fan out much more than to the north of that island. Indeed, there are several considerable islands reaching out into the Atlantic. The Outer Hebrides are not masking the influence of the Atlantic on this area as they do on the north coast of Skye. The influence of the Atlantic Ocean on this zone is both direct and inhibitory, and indirect and encouraging to a wealth of plant growth. The island of Islay, for example, changes character completely between its western and eastern halves. On the Atlantic side there is the lack of trees and shrubs and the presence of short sweet herbage salted by the spray from innumerable south-westerly gales, whereas there are beautiful gardens, palm trees and some forestry on the south and east sides. The Rhinns of Islay on the Atlantic coast are not heavily covered with peat as is a good deal of the eastern half. Islay is an island of many good arable farms, and it has several square miles of limestone country.

The waters of the North Atlantic Drift cast up on these Atlantic shores pieces of wood and beans of West Indian origin, and plants such as the pale butterwort (Pinguicula lusitanica), pygmy rush (Juncus pygmaeus) and the moss Myurium Hebridorum which occur again on British coasts only in the south-west, here turn up in fair numbers. The pale butterwort occurs in the bogs of Portugal and western Spain, and on the west coast of France; Myurium moss is found in the Azores, the Canaries and St. Helena as well as in our Outer Isles. Dwarf cicendia (Cicendia pusilla) has also turned up in this zone, though previously found in the British Isles only in the Channel Islands. More recently, Campbell and Wilmott (1946) have found another Lusitanian plant in Stornoway Castle park, namely Sibthorpia europaea. The work of Professor Heslop Harrison and his group from the University of Durham should be consulted. It is his opinion that these western cliff edges escaped the last glaciation and thus their Pleistocene flora was not exterminated. Others hold that the flora must have been introduced since then.

Jura is not so well served with the rich quality of vegetation we may find in Islay or even in small Colonsay and in Mull. It is composed of quartzite, which is poor stuff. Jura is also heavily covered with peat and suffers in consequence. A thick blanket of peat has a very great depressing effect on the variety of vegetation and in limiting the growth of deciduous trees. Jura is an island of high hills. The Paps rise to 2,571 feet and are quite rough going. It was on these hills that Dr. Walker of Edinburgh in 1812 conducted his classic experiment on the differential boiling-point of water at sea level and at the top of the Paps. Jura has a very small population of human beings on its nearly 90,000 acres. The island is so poor that its long history of being a deer forest will probably continue. In mythological literature Jura appears as being uninhabited and a place where heroes went a-hunting. It was on Jura during the latter part of the 19th century that Henry Evans conducted careful studies on the red deer. His were the first researches of a scientific character on Scottish red deer, yet he never set out to be more than a scientific amateur.

The island of Scarba, of about 4,500 acres, high and rocky, lies north of Jura. The Gulf of Corrievreckan is in the narrow sound between the two islands. This celebrated whirlpool and overfalls is caused by the strong tide from the Atlantic being funnelled through a strait, the floor of which is extremely uneven. The sound is quiet at the slack of the tide but is dangerous to small craft when the tide is running. The largest whirlpool is on the Scarba side of the sound, but there is a spectacular backwash on to the Jura coast which used to be reckoned very dangerous in the days of sailing boats. The maximum current is probably about 8

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knots which is very fast for a large bulk of water. No herring drifter or ordinary motor fishing-boat could hope to make headway against such a current, for their maximum speed in calm water is not more than 10 knots.

This West Highland zone has what the North Minch lacks, a number of sizable islands which are not big enough to lose their oceanic quality, and not so small that they are utterly windswept. The islands of Colonsay and Oronsay, west of Jura, are an excellent example of islands which have the best of almost all worlds. Naturalists may be glad that Colonsay is in the possession of one who recognizes its value and beauty in the natural history of the West. Most of the island is of Torridonian sandstone of a different complex from that farther north, but there are overlays here and there of limestone and its derivative soil, and the 100-foot beaches are another place of good soil. There are sand dunes, cliffs and rocky beaches where several rare maritime plants are to be found. There are fresh-water lochs with water lilies and the royal fern in profusion. Natural woods of birch, oak, aspen, rowan, hazel, willow and holly also occur, and beech has been planted. The sight of these, so near the Atlantic and its gales, may be imagined from this short passage from Loder’s exhaustive book:

“The woods are being rejuvenated by young plantations of Birch and Aspen, which are springing up naturally and contending for supremacy with an annual luxuriant growth of bracken. The Woodbine twines over the trees, and festoons along the edges of the numerous rocky gullies that cut up these slopes. Ivy has climbed up and formed pretty evergreens of the more stunted of the forest trees. The Prickly-Toothed Buckler Fern grows in profusion, and the little Filmy Fern is also to be seen under mossy banks.”

There has been considerable planting of coniferous and deciduous trees for amenity in this Atlantic island so that it now presents a luxuriant and well-wooded aspect in the neighbourhood of the house. But in gazing on these woods now and noting Colonsay’s wealth of small birds, we should remember the effort entailed in beginning to establish these conditions. Loder says:

“When planting in the island first began, the trees made so little headway that it was considered amply satisfactory if they formed good cover. For the first ten years or so they made little progress, and many places had to be planted over and over again. Protection from animals and weather was provided in the first instance by dry-stone dykes, 5 feet high. Alder and Sea Buckthorn were planted along the most exposed edges. Alders and various species of Poplar were used in wet situations but the poplars did not last well, and were liable to be blown over. It was only as the trees made shelter for each other that they began to show any vigorous growth. Indigenous species such as Birch, Oak and Rowan, have sprung up on hilly ground where the planted trees failed to establish themselves.”

The trunks of trees in these Atlantic places tend to become covered with lichens such as Parmelia perlata and Usnea barbata, and mosses such as Eurhynchium myosucoides (on birch), Ulota phyllantha, Hypnum cupressiforme and Brachythecium rutabulum. These trees seem to be much more affected by the humid climate than such exotics as Escallonia, Ceanothus, Verbena and Mimosa (Acacia) which grow luxuriantly. This is one aspect of Colonsay, but there are also its sedgy and heathery moors like those of many another island of the West, and at the southern tip, where the Atlantic has full play over the Torridonian and mudstone slabs gently rising from the sea to make platforms and pools near the tide level, the Atlantic grey seal breeds in fair numbers. Elsewhere, on the cliffs, kittiwakes, razorbills and guillemots breed; and there are three species of tern, arctic, common and little, breeding on the island.

Colonsay and Oronsay together might well be looked upon as an epitome of the West Highland world in its full range and consequences of Atlantic exposure and sheltered mildness.

Farther to the north-west are Coll and Tiree, two more islands which receive practically the full force of the Atlantic, but which show decided differences in natural history. Tiree is very low indeed. The rocky portion of the island, of Lewisian gneiss, reaches its highest point in Ben Hynish, 460 feet, but by far the greater part of Tiree (Plate 25) is but a few feet above sea level and composed of blown shell sand resting on a platform of gneiss. The island is one of good-sized arable crofts and is so far different from most West Highland districts that it has a Clydesdale horse-breeding society of its own. The sandy pastures of Tiree are deficient in cobalt but recent researches in mineral nutrition of animals have allowed the farmers of Tiree to dress the land with as little as 2 lbs. an acre of a cobalt salt and prevent the onset of pine in sheep. The island has particular interest for the birdwatcher: first, it is on a migration route and gets both summer and winter visitors which would not be seen anywhere in the North Minch, and its rich arable land also attracts a large number and variety of birds. Loch Vasapol of Tiree is a famous place for various duck. Tufted duck breed there and the gadwall is found there in winter though so uncommon elsewhere in the West. The vast beaches encourage certain waders, including the bar-tailed godwit, sanderling and greenshank. In the past the snipe-shooting was reckoned the best in Europe. Happily, there is less of it now.

Glacial action in Tiree is shown by the Ringing Stone, a huge rounded boulder of augite which probably came to rest there after a journey in the ice from Rum. The stone is marked by many ringed hollows on its surface.

The island of Coll, once one is within it, reminds one of the low gneiss country of Sutherland. Here the innumerable little hills are still smaller than in Sutherland and not so steep, none rising above 339 feet. The island presents a uniform rocky appearance when seen from a distance on the east side. On the west side of Coll are miles of shell-sand dunes, a feature which tends to be characteristic of many of the islands which meet the full force of the Atlantic and are low enough to have allowed the sand preliminary lodgment. The interior of Coll is just peat where it is not bare gneiss, yet with its western pastures it has always had the reputation of being a good place for cheese and sound dairy cattle. This island is important for the student, of distribution of plants in relation to the last glaciation and associated changed ocean levels.

The low, sandy islet of Gunna lies between Coll and Tiree. It is a great place for Sandwich, common and arctic terns and I believe the little tern nests there too. Such burrowers as the sheld-duck are plentiful, of course. Barnacle and grey lag geese are common in winter.

The small group of tertiary basalt islands known as the Treshnish Isles lie between Coll and Mull. The most southerly one has a rounded cone of an old volcano, 284 feet high, which gives the island the name of Dutchman’s Cap (Plate Va). The middle island of the group, Lunga, also has a volcanic mound rising to 337 feet, but the other small islands are all flat-topped with sheer sides of amorphous basalt resting on a platform of lava. This platform is of great importance in the natural history of the Inner Hebrides because it makes a breeding ground for the Atlantic grey seal. The Treshnish group, especially the Harp Rock of Lunga (Plate XIXa), is a nesting place of kittiwakes and auks and fulmars. Storm petrels nest in the Treshnish also, and the Manx shearwater on Lunga at least. The quality of grass on these islands is excellent and attracts a vast flock of barnacle geese in winter. The green rich grass of the islands is reflected again in the presence of large mixed flocks of starlings and peewits. In winter-time hundreds of blackbirds and a good many thrushes live on the Treshnish group. Lunga, being infested with thousands of rabbits, has a stock of seven buzzards.

The Cruachan of Lunga will be a good place to rest for a few moments and look at the topography of Mull, that very interesting member of the Inner Hebrides, Mull of the Mountains as the Gael calls it. The eye is first struck by the shapely peak of Ben More, 3,169 feet. This is the highest point reached by the tertiary basalt in Scotland. The cone itself is the result of great weathering, and the various beds of this amorphous lava are evident now in the truncated edges of the lower slopes of the hill. For sheer hard going, the descent from the summit to Loch Scridain takes a lot of beating, for the traveller is constantly having to make his way round these faces of rock which are not readily obvious to him as he comes down the hill. The terraced quality of Mull is obvious in a large part of Loch Scridain, the terraces being exactly the same height on either side. The peninsula between Loch Scridain and Loch na Keal reaches on the north side a stretch of some miles of very fine cliffs with sweeping talus slopes at their foot. The cliffs of Balmeanach are to my mind one of the striking features of Mull. The 1,600-foot basalt cliffs have trapped the cretaceous sandstone layer beneath them. The cretaceous sandstone—the local representative of the chalk—may be found in a narrow stratum just above sea level. These cliffs are difficult to explore and remain largely unexplored. Down below, the small island of Inchkenneth, the burial place of old Scottish kings and chieftains, is also composed of low strata of this cretaceous sandstone. If there is anywhere where chimneys must have cowls it is on Inchkenneth, for the down draughts from the great cliffs in a south wind are tremendous. Slates have to be specially cemented on the roofs. Corn and hay stacks suffer badly in this abnormal situation.

The whole of the north end of Mull consists of green even terraces with occasional gullies. The islands of Ulva and Gometra are similarly terraced flat cones with occasional gullies. The ground is porous and does not form basins for freshwater lochs; peat is absent. Bracken grows rampant here; indeed, Ulva is almost a museum piece for showing what luxuriant growth bracken can make in the Highlands. On the terraces, only the tips of the horns of Highland cattle can be seen above the fronds, but in the gullies the bracken tries to reach the same height as the plants on the terraces and may grow to a height of 12–15 feet. Trees of many kinds grow well in the sheltered parts of Mull on this soil from the volcanic rock. Just as trees were impossible on the tertiary basalt cliffs of Balmeanach and on Inchkenneth, they reach extraordinary luxuriance and beauty where the calcareous cretaceous sandstone appears again round the edge of Carsaig Bay on the south coast of Mull. This pocket will well repay a visit from the botanist and, I should imagine, from the entomologist. The cliffs to the west of Carsaig are by no means as impressive as at Gribun, but in their face there is to be seen a fine fossil tree fern first brought to the notice of geologists and naturalists by Dr. Macculloch in the early 19th century (Macculloch, 1824). Delicately coloured crystals are also to be found in these cliffs of the south coast.

The south-east end of Mull is dominated by bosses of gabbro called Sgurr Bhuidhe and Creach Bheinn (2,352 and 2,344 feet). From them we may look down on the north side to the long, bare, impressive valley of Glen More and on the south to the tree-lined waters of Loch Uisge and Loch Spelve. The southern peninsula of Laggan, formed by Loch Buie and Loch Spelve and almost made an island by Loch Uisge, reaches nowhere to more than 1,250 feet, but it is extremely rough and rocky, with plenty of scrub birch. Few people have walked through that ground which for many years now has been kept as a small and very private deer forest of 5,000 acres.

The islands of Muck and Canna are both of tertiary basalt on an erosion platform at tide level of lava that looks like clinker. Their soil is so good and their position in the Atlantic so favoured that these islands can grow what are probably the earliest potatoes in Scotland, i.e., May 31. The sheep of these islands do extremely well and come to the mainland in such good order that mainland buyers are hesitant to buy the lambs because they know they have nothing so good to offer them to keep them growing. The wealth of species of insects, molluscs and other invertebrates on these tertiary basalt islands is much greater than would be found on those of the Torridonian or gneiss formations, even though the basalt does not tend to allow lochans to form. The Glasgow University Expedition to Canna in 1936 published a full report of their extensive finds. Muck and Canna both offer the right kind of cliffs for sea birds, and Canna is also a breeding station for the Manx shearwater.

The island of Eigg (Plate 5) is a big shearwater station, the birds nesting well up towards the Sgurr, 1,280 feet. The Sgurr is the most obvious physical feature of Eigg and by far the island’s most interesting natural phenomenon. It is a geological curiosity which has shed light on the geology of other areas far distant. The late Sir Archibald Geikie solved the riddle which Hugh Miller answered unknowingly at an earlier date. The Sgurr itself is of pitchstone, resting on a thin river bed of conglomerate which contains fossil pieces of driftwood from some far distant time. Beneath this is the tertiary basalt again. The pitchstone shows columnar jointing in places, a character which is still more strongly marked on Oidhsgeir, 18 miles away to WNW. This low islet of pitchstone is considered to be part of the same sheet as the Sgurr of Eigg. There is one other feature of Eigg deriving from its geology which should be mentioned here—the musical sands of Camus Sgiotag, a small bay on the north side of the island. These sands are of partially rounded quartz grains of similar size. If the sand is dry a shrill sound is heard as one walks over it.

To return for a moment to the few acres of Oidhsgeir, an islet which does not reach higher than 38 feet above sea level. Here on the top of the pitchstone columns which are 8 inches or so across the top are found the nests of kittiwakes in the season. There are also great numbers of common and arctic terns and eider ducks. Harvie-Brown, visiting the islet several times in the ’80’s and early ’90’s of last century found teal breeding and was convinced that the pintail duck had nested there also. This phenomenon of a small islet in the open sea gathering to it an immense number of living things for the purpose of their reproduction is one to which we shall return in a later chapter on the oceanic island. The deep-cut channels among the pitchstone columns are also a playground for the Atlantic seal. One channel on the south side runs up into a pool where a boat may lie in perfect safety. Many are the occasions when lobster fishers and venturers in small boats have been glad of the quiet pool of Oidhsgeir. What a strange feeling it is to be lying snug in such a place with the mighty ocean pounding but a few yards away and the spray flying over!

The island of Rum, with its three rock types of gabbro, Torridonian and granite, is for the most part a closed book to naturalists. We may hope this unfortunate period of its history is drawing to a close and that it may yet have a future as a priceless wild-life reserve. There are red deer and wild cats on Rum, there are otters round the shores and on the burns, and such species as badgers and roe deer could be introduced if introductions were thought desirable. Some of the finest kittiwake cliffs in the kingdom are to be seen on Rum, and the Manx shearwater nests in holes high up the 2,600-foot hills. The golden eagle is there still, though the sea eagle disappeared during the second half of the 19th century. Given the chance, we may expect the chough to return to Rum.

Skye may be looked upon as the northern outpost of the Lusitanian zone. It has suffered human depopulation like many another Highland area, but Skye is still one of the most heavily crofted areas of the West. Preservation of game has practically ceased and almost all the hill ground is now crofters’ grazing. Topographically, Skye is magnificent, with its Cuillins and its Quirang, but from the point of view of wild life it is somewhat disappointing. The whole area facing the Minch is faunistically poor, as was pointed out by Harvie-Brown fifty years ago.

The island of Raasay, however, between Skye and the mainland, has a surprisingly rich variety of small birds, doubtless as a result of the woods and the large amount of park-like ground which is of Liassic origin. Personally, I should say that the Lepidoptera of Skye and Raasay would repay close scrutiny, not only from the point of view of numbers of species, but from the areas of distribution. Heslop Harrison and his group have already made fruitful researches in this direction. Raasay, like Mull, has its own sub-species of bank vole (Clethrionomys = Evotymys).

The islands of the Atlantic zone are by far the most interesting part. The mainland coasts are often hidden and tend to lose character. But the country bordering the long sea lochs is of exceptional beauty and contains some habitats—such as the indigenous oak woods—which are almost unique in Scottish natural history. To walk the length of Loch Sunart, ten miles out of the twenty through these oak woods, in the fine weather of June is an aesthetic experience, if only for the sight of the redstarts which are here in great numbers. The scenery of the distance is as beautiful as the redstart among the oaks and hazels near at hand. Perhaps the better way is to travel eastwards from Kilchoan and Ardnamurchan Point where the quality of ocean is apparent as on the islands. Sanna Bay on the northward tip of Ardnamurchan is one of the most beautiful shell-sand bays of the West, but it is rarely visited because of its remoteness. East of Glenborrodale the sense of sea is lost and we are in the woods with the loch below us. The peak of Ben Resipol, 2,777 feet, dominates the landscape and is most shapely when seen from this airt. The traveller can hardly miss seeing Ben Iadain, 1,873 feet, and on the other side of the loch in Morvern. It is a little cap of tertiary basalt perched on the Moine schist, but between the two is a very narrow band of chalk. The sight of this little hill cannot fail to impress one with the immense amount of denudation which must have taken place to remove this molten layer of amorphous volcanic rock from so much of this countryside.

Though the oceanic birds such as kittiwakes and auks are lost as one moves up these long sea lochs, it is surprising how many sea birds are to be found breeding in the season. Arctic terns, eider ducks, herring gulls and mergansers—all are here in numbers. And where there are shallow shores and estuaries there are parties of curlews, oystercatchers and ringed plovers. The hillsides above these long sea lochs are almost devoid of heather. The vegetational complex is one of various species of sedge, a few grasses such as flying bent and mat grass, and bog myrtle and deer’s hair sedge. Heather will appear at the edge of a gulley perhaps where the drainage is good. From a distance the most obvious plant may be bracken—great sheets of it, darker green in summer than the herbage and red in winter.

The ecology of the long sea lochs and their intertidal zones is a subject of great interest for those who have the techniques to follow such studies. The gradual increase in salinity from head to foot of the loch, the diurnal variation caused by the tide, the spasmodic variations caused by spates and droughts, the currents formed, and their effects on the life of the waters, still remain to be worked out in detail. Space will not allow of individual description of all the narrow and long sea lochs from Loch Fyne to Loch Alsh: each one has its similarities and distinctions, and certainly each should be visited by the naturalist who is also keen on good country. Most of these narrow lochs have high hills rising from their shores, which means that their south side loses the sun for four months in late autumn and winter. Loch Hourn is particularly sombre in winter because the hills of Knoydart, which reach to 3,343 feet, seem to tower above the loch. Loch Nevis, on the other hand, is sheltered from the north by these same hills, and the North Morar hills to the south of this wider loch do not rise above 1,480 feet. Inverie, therefore, in its sheltered bay on the north side of Loch Nevis, is one of the kindest places in the West Highlands, despite the high rainfall. Indeed, the West Coast is full of these pockets of kindly shelter allowing luxuriant growth. Many of the policies of the large houses have magnificent specimen trees which have grown within a hundred years or so to a size which would have been impossible in a large part of England.

When these sea lochs narrow at their mouth there is a diurnal tide race of considerable force. That at the Corran Narrows of Loch Linnhe runs at 8 knots at ebb and flow, but that at Connel Ferry on Loch Etive is very much more than this and is quite impassable at half tide. When the tide begins to flow here there is the extraordinary sight of a waterfall in reverse, made by the inrush of sea water.

This section may be concluded with mention of the fine piece of country round the shores of Loch Etive (Plate Vb) and up to Glen Coe (Plate 6). Ben Cruachan, 3,680 feet, is one of the landmarks of the Highlands. Cruachan and Ben Starav, 3,541 feet, are of granite and lie either side of Glen Kinglass which runs from the east bank of Loch Etive. There is happily no road through this glen and it is therefore almost untouched. The sides are lightly wooded; the river is of that clarity which is common in waters coming off granite, and as one climbs past the trees and by numerous falls the Forest of Blackmount is reached. This great high place has lost all western character which was expressed at the foot of Glen Kinglass. Blackmount has always been deer forest. Its swan song is that charming book by the late Marchioness of Breadalbane, The High Tops of Blackmount. You may object to all that this great lady stood for, but if you have a fine taste for country and appreciate writing which conveys the atmosphere of particular country you should read her book.

If one makes a cross-country trek from the heart of Blackmount to the head of Glen Etive, a country of high, spiry peaks is reached. What is more, it belongs to the nation. The Royal Forest of Dalness, Buachaille Etive, Bidean nam Bian, and some of the best climbing ground in Scotland is included, and it is probable that adjacent areas will also come under state ownership before long. The botanical and geological interest of the area is considerable, but the student of animal life will find it rather bare. Once more, at the head of Glen Coe we are on the border of our zone. As we look eastwards across the dreich Moor of Rannoch (Plate VIa) it is into Central Highland country.

THE OUTER HEBRIDES OR OCEANIC ZONE

This is the most westerly portion of Scotland, the seventh degree of West Longitude passing down through the middle of this long range of islands which effectually shields the northern half of the West Highland coast. If we study a population map we see that the greater part of the people on the Long Island, as the whole group is called, are fairly densely packed on to the western fringe. Some more dense places are also found on the extreme east of Lewis, as on the Eye Peninsula or Point as it is always called in Lewis. By merely looking at a map one might ask why the people are so densely grouped on the west side where harbours are fewer and where the force of the Atlantic Ocean is unbroken. The very fact of human density of population is surprising to anybody accustomed to the alarming rate of depopulation on the mainland shore of the West Highlands. The Hebridean has a love of home which is unconquerable. There he has remained through thick and thin, sticking to his fringe which is between the mighty ocean and the deadening peat bog of the interior.

The half-million and more acres of the Outer Isles mean nothing in relation to the human population which lives there because to a large extent the interior is just as uninhabitable as the ocean. The people being confined to the coastal fringe live what might be called an open urban existence without town planning.

The overpowering reason for the human species being confined to this fringe is that here the awful blanket of peat ends and the ocean has thrown up an immense weight of shell sand. As the dunes have stabilized through the millennia and the stiff marram grass has given way to kinder herbage, a light lime-rich soil has formed. There are miles and miles of the white sand on the Atlantic shore, and above it the undulating machair (Plate XIXb) of sweet grass on which are reared great numbers of Highland and cross cattle. Flocks of barnacle geese come to the machair in winter and add to the humus content of the sandy soil. The prevailing south-westerlies continue to blow winter and summer, year after year, century after century. The tangle from the shallows of the ocean, the various Laminarias of the marine botanist, is torn from its bed and washed up on the beaches. Man comes down with his ponies and carts and creels and takes up some of it to spread on ploughed portions of the machair. All these things are helping to make soil, and the sand itself in these gales, especially if the winds are dry, is being blown up towards the blanket of peat which overlies the archaean gneiss of the Hebrides. The sand sweetens the peat, causes its barren organic matter to be unlocked and become fruitful of herbage for man’s beasts. Their dung still further ameliorates the peat. Such is the constant process, in which the storm is a necessary and beneficent factor in allowing and maintaining fertility. But once the coastal strip is crossed the peat reigns supreme. Its blanket must have increased about ten feet since early man came to the Outer Isles, for only the tops of the fine Megalithic stones at Callernish, Lewis, were showing when Sir James Mathieson of the Lews undertook their excavation. The landscape in the bog is shortly described—a low undulating plateau of peat, bare grey rock of gnarled shape, and thousands of small and large lochans of brown acid water. If we wander through these areas of peat we shall come upon drier knolls where the rock comes to the surface or is not far beneath, and here we shall find turf and greenness for a space. The shielings of Lewis have been and still are here. They are the summer dwellings of a pastoral people taking advantage, for their cattle and sheep, of the short spell when the peat grows its thin crop of sedge and drawmoss. The people lived on the little knolls as on islands, bringing their cattle up to them twice a day for the milking; throwing out their household waste—little that it was—and adding their own quota of dung and urine. The shieling life is mostly gone but the green knollies in the sea of rock and peat remain.

We may digress at this point to consider the nature of peat, this substance which covers a million and a half acres of the Highlands and Islands and the existence of which is a most important factor in the natural history of the area and of the scenery. A study of the peat is interesting not only for what it grows and harbours now, but for the history to be deduced from a deep profile of it. Peat forms under the influence of certain definite conditions and their consequences: the first requirements are high precipitation and a general coldness of atmosphere in the growing season sufficient to inhibit bacterial activity in the waterlogged soil, but not cold enough to prevent growth of certain plants. A vegetational complex of sour bog plants, such as sphagnum moss (Plate 22b), sedges of various kinds and cross-leaved heather, soon occupies the ground to the exclusion of all those plants which need a well aerated soil and a supply of basic compounds. The rain impoverishes the original soil by washing out plant foods and then, by creating waterlogged and therefore anaerobic conditions, prevents the action of normal soil bacteria in breaking down the dead vegetation into humus. Such necessary decomposition does not keep pace with vegetative production by the plants, so that a gradually thickening layer of peat forms. The peat, thus composed of organic matter without lime, is highly acid in character, which is a still further check to bacterial action. Even the run-off water from the poor rocks such as gneiss and Torridonian is charged with unneutralized carbonic acid. With compaction and age, the peat becomes colloidal in texture, a fact of much influence in the behaviour of peat in holding water or being dried. The normal water content of peat as it lies in the bog is as high as 93.5 per cent.

Peat varies in consistency from being highly fibrous to the state of a black amorphous substance, depending on age and the type of vegetation. The Highland crofter is well aware of these details and his methods of winning peat for fuel vary from place to place. Cottonsedge peat is tough and fibrous and can be “footed” (i.e. set up on end to dry in pyramids of four bricks) and handled later with very little loss. Lower, older, amorphous peat is very brittle and cannot be set up.

The ages of the peat deposits have been tentatively fixed as beginning about 7000 B.C. at the close of the Boreal period. The warmish dry climate which grew forests of pine, birch and hazel now became warmish and wet, bringing about destruction of the scrub hazel vegetation by moss. The Atlantic period closed between 5000 and 4000 B.C. and a cooler and somewhat drier sub-Boreal period set in with a rapid development of peat. This continued until near our era which may be termed cold and wet and sub-Atlantic. The peat to-day is still making in some places as on the main bog of Lewis, and receding in others, as in parts east of the Cairngorms where the stumps of forest trees are coming forth as the peat crumbles away. Continual burning on western hills is probably having more influence than we know in checking or denuding the peat which is the only cover the rocks have, but in Lewis there is very little burning, the slopes are gentle and the succession of blanket bog is not being much disturbed, except by cutting for fuel.

The colours of the Atlantic coast are vivid blues and greens and the bright cream of sands. Inland, sombre colours are paramount and the lochans do not reflect the colour of the sky from their dark depths as does the sea above its floor of white sand. But the Hebrides are not all a dark plateau. The southern end of Lewis (Plate VII) and most of Harris are hilly. The Forest of Harris gives us rough going as anywhere in the Highlands and the Clisham rises to a fine peak of 2,622 feet. The red deer which live in these fastnesses are small, but have very well-shaped heads. The pine marten was also to be found there until recently. Its very wildness is the best protection this piece of country has. The lower deer forests of Park and Morsgail are fairly heavily poached of their deer, in an island of such heavy human population.

The Hebridean burns a lot of peat. His peat stacks are far larger than those of the mainland. By cutting peats he is doing two jobs—providing the wherewithal for comfort at the fire, and removing some of the great pervading blanket. He does not come upon bed rock at the foot of the peat banks but on to a layer of boulder clay which, when mixed with the top thin layer of sedge and peat, will shortly turn into fairly good soil providing much better grazing than anything from the top of the peat. The boulder clay came there by glacial action before the peat was laid down. Our Lewisman makes new ground this way and there is no doubt that if the modern mechanical tools such as the scraper and bulldozer were brought into operation on what is commonly called the skinned land, the agricultural scientist could make much good land in Lewis without attempting to conquer the upper layer of the peat.

As might be expected, the bird life of the interior of the Outer Hebrides is poor in variety and scanty, the nesting grey lag geese and red-necked phalarope (Plate XXXIIa) being probably the most interesting members. The geese feed on the crofting ground and on the machair but return into the maze of the interior to nest. The coasts are rich in sea birds, ducks and waders.