is the great granite mass of Dartmoor, one of the most prominent
features of the county, measuring 225 square miles in extent, and
constituting the largest granitic area in England. Granite is a volcanic
rock, formed, it has been suggested, by fusion at a great depth and
under great pressure, and consisting in the main of three minerals,
quartz, felspar, and mica. That of Dartmoor is, on the whole, grey and
coarse-grained, but it varies a good deal in colour, fineness, and
composition. Its real origin is obscure. It has been assigned by various
experts to various periods, and it has been called "the sphinx of Devon
geology." There can, however, be no doubt about the great disturbance
which has been caused in the county by upheaval and by the intrusion of
melted rock, which has bent, broken, and twisted previously-existing
formations in a most extraordinary manner, the results of which are well
seen in the picturesque scenery of the Start, Prawle Point, and Bolt
Head. Lundy, which is twelve miles from the nearest point of Devonshire
mainland, is all granite, except for a small part of its south end,
which is Millstone Grit.
A long interval of time appears to have followed the laying down of
the Culm measures, during which so vast an amount of shattered rock
was worn away that when the beds that come next in order--the New Red
Sandstones--were formed, they were, in places, deposited directly upon
the Devonian, the superincumbent carboniferous or Culm strata having
entirely disappeared. The New Red Sandstones occur chiefly in the east
of the county, where their lower beds fill up old creeks and valleys
in the carboniferous system; and they extend northwards from the coast
past Exeter as far as Holcombe Regis, forming broad bands on either
side of the Exe, characterised by the high fertility of the overlying
soil, and with one long spur traversing the heart of the county, past
Crediton and Exbourne, with isolated patches round Hatherleigh, and with
another and less extended prolongation a few miles west of Tiverton.
The Lower New Red consists of clays, conglomerates, red breccias and
sands, in which occur many outcrops of trap, the evidence, not only of
numerous eruptions, but of eruptions extending over a long period of
time. These beds contain no fossils, except in fragments of older rocks.
The Middle New Red, in the form of thick beds of red marl and red and
white limestones, well seen on the south coast, is covered in turn
by the Upper New Red, with beds of pebbles, some of which are derived
from the Devonian and even from the Silurian. In this formation, near
Sidmouth, have been found the remains of two remarkable reptiles, the
_Hyperodapedon_, a strange form allied to the existing tuatera lizard
of New Zealand and in England only known elsewhere in the formations
of Warwickshire, and the _Labyrinthodon_, so named from the intricate
structure of its teeth, and also called _Cheirotherium_, from the
hand-like impressions of its feet.
[Illustration: Footprints of _Cheirotherium_, New Red Sandstone]
The Rhaetic beds are not well seen in Devonshire. They occur on the
coast between Lyme Regis and the mouth of the Axe, and in the estuary of
that river, but are much hidden by landslips of cretaceous formations
from above. One layer, consisting of black shale, with bivalve shells
such as _Cardium_ and _Pecten_, contains also a bone-bed, with remains
of fish, such as _Acrodus_ and _Hybodus_. The former is represented by
its blunt teeth, and the latter, which was a huge, shark-like creature,
by its long and formidable-looking fin-spines.
The Lower Lias is exposed in a narrow strip of coast from the Devonshire
border to the mouth of the Axe, and to a greater extent in the valley of
the river above Axminster. It has been divided on the coast into four
distinct zones, each characterised by its own particular species of
ammonite.
The cretaceous formations occupy a much wider area, but they also
are confined to the southern part of the county. The Greensands of
the Blackdown and Haldon Hills have been divided by geologists into
fifteen layers, varying in thickness from a few inches to as much as
thirty-five feet, some with few fossils, and some very rich in animal
remains. _Trigonia_ and _Inoceramus_ are found in almost all the zones:
other forms less widely distributed are _Murex_ and _Turritella_. Chalk
occurs on the south coast from the Dorset border to Sidmouth; and in
isolated patches it extends inland as far as the Blackdown Hills, and
also further west, in the Haldons. The Lower Chalk, well seen on the
coast and to the west of Hinton, is made up of calcareous sandstones,
with ammonites and pectens. The Middle beds, composed of white chalk
with flints, the zone of _Terebratulina gracilis_, is exposed at Beer.
The lower and harder layer is characterised by _Rhynconella_. The Upper
Chalk also holds many flints, with echini; _Holaster_ in the lower, and
_Micraster_ in the upper strata.
Last of all come the tertiary deposits, which, however, occupy only a
small area in the south-east, chiefly in the valley of the Teign, from
Kingsteignton to Bovey Tracy; and there are a few isolated patches, as
for example near Bideford and at Plymouth. These beds consist of clays,
some of them of much value, with flints from the chalk, and gravels and
beds of sand derived from the wearing away of older rocks. The most
interesting feature of this formation is the lignite of Bovey Tracy,
on the eastern edge of Dartmoor. Lignite, otherwise known as brown
coal, consists of the imperfectly fossilised remains of tropical or
sub-tropical vegetation, such as the palm, cinnamon, and laurel, amongst
which are found lumps of resin. By far the most abundant remains are
those of a very large tree allied to the sequoia of California. It is
very remarkable that in the Pleistocene clay above the lignite are found
stems and twigs of Arctic birch and willow, suggestive of a far colder
climate than prevailed in Tertiary times, when the trees that went to
form the lignite were growing.
To the Pleistocene period also belong the gravels and alluvial deposits
of some of the river valleys (those of the Exe and the Teign, for
example), the blown sands of Braunton Burrows and elsewhere, the raised
sea-beaches, the submerged forests, and the cave-deposits which are
alluded to in other chapters.
7. Natural History.
It is generally believed by naturalists that the ancestors of most of
our fauna and flora reached this country at a time when what we now call
the British Isles formed part of the mainland of Europe, and when there
was no intervening sea to bar the way.
Before this colonisation was complete, however--that is, before all the
different kinds of European beasts and birds had made their way to the
extreme western districts--communication with the continent was broken
off. The land of the north-western districts of Europe sank. The sea
flowed in, forming the German Ocean, the English Channel and the Irish
Sea, and the influx of animal life was stopped.
This is the reason why there are more than twice as many kinds of land
animals in Germany as there are in England, and nearly twice as many in
England as there are in Ireland. This is the reason why there are no
snakes in Ireland, and why the nightingale, on returning from the south,
never crosses into the sister kingdom.
On islands that have long been separated from a continent it is found
that forms of life tend to vary in the lapse of time, and that fresh
species are developed. That it is not long, as geological periods go,
since Great Britain became an island, is shown by the fact that we have
no quadruped or reptile except the Irish weasel (_Mustela hibernica_),
and, setting aside minor differences which some writers have magnified
to the value of a species, only one bird, the red grouse, which is not
also to be found in Europe. Very different is the case in Japan, which
was separated from the mainland of Asia so long ago that new species
have had time to develope; and the islands of that country contain many
kinds of beasts and birds which are unknown on the adjacent continent.
Some of the animals which came from Europe into Britain have died out,
either because the climate changed and so cut off their food supply, or
because they were destroyed by the hunters of the Stone Age. The bones
which have been found in Kent's Cavern at Torquay, and in other caverns,
afford clear evidence that the mammoth, the lion, the bear, and the
hyaena once roamed over the hills of Devonshire.
Although there are many more species of beasts and birds on the
continent of Europe than there are in this country, both birds and
beasts are numerically much more common here. Nothing strikes a
naturalist more forcibly when travelling in France or Italy, for
example, than the scarcity of wild life, and especially the fewness
of the birds. It is true that we have fewer species, but we have many
more individuals. To this, several causes have contributed. Englishmen
do not, as is the custom in many European countries, shoot or trap for
food small birds of every description. And game preserving--although
it has been fatal to the larger birds of prey, such as kites, falcons,
and buzzards, and keeps down other species, such as jays, magpies, and
carrion crows--provides innumerable sanctuaries for great numbers of the
smaller birds, which are safe from harm during the breeding season.
The natural features of Devonshire are so varied in character, including
as they do large areas of wild and uncultivated and thinly-inhabited
country, together with many well-wooded and sequestered valleys, and
wide stretches of bog, salt-marsh, and sea-coast, that it is very
rich in both animal and vegetable life. Its marine fauna and flora,
in particular, are of very great interest, and are among the most
remarkable in England.
[Illustration: A Red Deer]
Nearly all the native mammals of the British Isles are found or have
been found in this county, from the "tall red deer" that has run wild on
Exmoor from time immemorial, down to the pygmy shrew, the smallest but
one of European quadrupeds, and weighing only one-tenth of an ounce, or
about forty-three grains and a half.
[Illustration: Otters]
Among the eight species of Devonshire bats is the very rare
particoloured bat (_Vesperugo discolor_), of which the only example
ever recorded in England was taken at Plymouth, having perhaps
travelled there in the rigging of a ship. It is probably more than a
hundred years since the last genuine wild-cat was seen in the county,
but both the marten and the polecat still survive in secluded spots.
Foxes are common, and there are still many badgers in some of the
Dartmoor valleys, where the two species have been known to inhabit
the same holt. Otters abound on all the principal streams, and are as
regularly hunted as the red deer and the fox. Devonshire is,
indeed, pre-eminent for its otter-hunting, and the Culmstock pack
is believed to be the oldest in the island. Harvest mice and dormice,
although widely distributed, are not numerous, and the original English
black rat is now rare.
Among the many marine mammalia that have been recorded for the county
are two kinds of seal, the sperm-whale, the common rorqual--of which
specimens nearly 70 feet long have been brought into Plymouth--the rare
bottle-nosed dolphin and the still rarer Risso's grampus. Bones of a
whale called _Balaenoptera robustus_, which were once washed ashore in
Torbay, are said to represent a species so rare that these and a few
similar relics stranded in Sweden are the only remains of it that have
ever been found.
Situated as Devonshire is, between the English and the Bristol Channels,
and containing widely-different physical features, suited to the needs
of species of very different habits, the list of its birds, including
residents, migrants, occasional visitors, and stragglers from the
Atlantic and even from America, is a very long one.
Among the larger land-birds which still hold their ground in the county
are the raven and buzzard, both of which are to be seen on Exmoor and
Dartmoor and on the coast, and the peregrine falcon, which has eyries
on both the northern and southern seaboards. A few pairs of choughs
still build in the northern cliffs; while such rare birds as Montagu's
harrier--first identified as a British species in this county--the
hoopoe, and the golden oriole still occasionally breed here, and might
do so regularly were they left in peace. Several birds, such as the
kite and the osprey, the latter of which now breeds nowhere in England,
and the former only in one solitary spot, have long since left the
county. Warblers as a family are less abundant than in some other parts
of the British Isles. The nightingale is nowhere common, but it occurs
every season near Ashburton and in the valley of the Teign. Owing to
the mildness of the climate it is not at all an unusual thing for a few
chiffchaffs and willow-warblers to spend the winter in sheltered valleys
on the south coast, instead of migrating to Africa in the autumn. The
ring-ouzel is a regular visitor to the open country of Dartmoor, while
the dipper haunts many of its streams. Two birds which have greatly
increased in numbers of late years are the jackdaw and the starling.
It is thought that the former has done much towards exterminating the
chough by destroying its eggs; and the latter, by taking possession
of its holes, has in many places driven away the green woodpecker.
Partridges and pheasants are numerous, but black-game, once abundant on
Dartmoor, have become so scarce that they are at present protected the
whole year round.
But by far the most abundant, and perhaps the most characteristic,
of the birds of Devonshire are the sea-fowl, the water-fowl, and the
waders, of which more than 140 different kinds have been recorded for
the county. Not only are its sandy shores, its bays and estuaries
and leys, haunted in autumn and winter by multitudes of northern
immigrants--swans, geese, ducks and a great variety of wading-birds; but
there are several spots along the south coast and a few on the north
where sea-birds regularly breed; while the reed-beds of Slapton Ley
provide sanctuary for great numbers of coots and for many wild-ducks
and teal, together with some rarer species. Herons are common on the
south coast and along the river estuaries, and there are heronries at
Powderham and elsewhere. A great black-headed gull (_Larus ichthyaetus_)
shot on the Exe in 1859, is the only one known to have been seen in the
British Islands.
There is, however, nothing on the mainland of Devonshire to compare
in ornithological interest with Lundy, which in the summer time is
a bird-lover's paradise. Gannets, once very numerous, have now left
the island, but cormorants, shags and gulls of various species here
build their untidy nests. Here multitudes of guillemots and razorbills
assemble in the spring and lay their great pear-shaped and boldly-marked
eggs on the ledges of the cliffs; while even vaster hosts of puffins
come back every year to take up their quarters in rabbit-burrows or in
holes which they have dug for themselves in the turf. Here the raven,
the buzzard, and the peregrine have fastnesses. Here, in chinks and
crannies, storm-petrels breed; and here, when darkness falls, the
startled listener may hear the weird, wailing cry of the night-wandering
shearwaters.
The few reptiles and batrachians of Devonshire present no points of
special interest. Vipers abound on Dartmoor, where they are commoner
than grass-snakes. It is curious that, while the palmated newt is
common throughout the county, the smooth newt and the triton are now
comparatively rare.
The freshwater fish differ little from those found in the neighbouring
counties; but there are fewer kinds in Devonshire than there are in the
midlands or in the east of England. Trout abound in all the streams, and
there are important salmon-fisheries on the Exe, the Dart, and other
rivers. A sturgeon seven-and-a-half feet long was once taken in the
Exe. Eels, which are hatched in the Atlantic, to the west and north of
the British Islands, at a depth of 3000 feet or more, come up from the
sea when they are two years old, and still very small, and ascend the
rivers, especially Exe, in enormous numbers. When they are mature, which
is not until they are several years old, they go down to the sea to
spawn, and never return.
It is, however, in marine zoology, for which few other parts of
England afford so rich a field, and for which its bays and inlets,
its rock-pools and stretches of sand provide ideal hunting-ground for
the naturalist, that Devonshire is most distinguished. Many famous
zoologists, such as Leach, Montagu, Parfitt, Gosse, and Kingsley have
won renown both for themselves and for the county by their researches;
while the Marine Biological Laboratory at Plymouth is constantly adding
to our knowledge of the multitudinous inhabitants of the sea. The
subject is so vast that only a few chief points can here be touched upon.
The sea-fish differ in marked degree from those of the east coast
of England. Plaice and cod, for example, are smaller here than those
caught in the North Sea and the latter are scarce; and the haddock, one
of the most important of east coast fish, is here almost unknown. Two
characteristic fish of the south coast of Devon are the pollack, which
reaches a great size, and the pilchard, confined to this county and to
Cornwall. Many southern and even Mediterranean species find their way to
these waters: notable examples are the gigantic tunny, one specimen of
which weighed 700 pounds, the beautiful rainbow wrasse, one of the most
brilliantly-coloured of all fish, and the boar-fish, which is sometimes
quite common. A number of rare species, such as Montagu's sucker and
the crystal goby, were first made known as British through being taken
off the Devonshire coast. Stray examples of the tropical bonito, the
flying-fish, the electric torpedo, and the sun-fish, one specimen of
which weighed 500 pounds, and the splendidly-coloured opal or king-fish,
have been recorded. Several kinds of sharks have been caught in these
waters, including the blue shark, the spinous shark, covered all over
with sharp prickles, the rare and formidable hammer-head, the huge
thresher, and the still larger basking-shark. The latter is, indeed, the
largest of British fish. Specimens have been caught measuring 30 feet in
length, and weighing more than eight tons. Marketable marine-fish will
be treated of in a later chapter.
Rich as are the Devonshire seas in fish, they are richer still in
crustaceans--crabs, lobsters, prawns, shrimps and their allies; and in
this respect ours is the premier county of England. Among a multitude
of species, two which have occurred nowhere else in Britain may be
specially singled out. One of these is the burying-shrimp, _Callionassa
subterranea_, a little creature something like a very small lobster,
with one claw--sometimes the right and sometimes the left--very much
larger than the other. It was one of Montagu's many discoveries, and was
found two feet deep under the sand of the Kingsbridge estuary. The other
rare species is the turtle-crab, _Planes minutus_, a few specimens of
which have been drifted ashore on fronds of Sargasso weed. The "small
grasshoppers" which Columbus saw floating in the sea a few days before
he sighted the New World, were, it is believed, not grasshoppers, but
turtle-crabs.
Other and very beautiful forms of marine life, such as starfish,
anemones, corals and other zoophytes, and sea-shells are very abundant.
And in spite of the comparative scarcity of lime in the soil of
Devonshire, the list of land and freshwater shells is a long one. It
is remarkable that _Limnaea stagnalis_ and _Planorbis corneus_, two
water-shells that are common in Somerset, are unknown in Devon. The
pearl-bearing mussel, _Unio margaritifer_, is found in both the Taw and
the Teign.
The county is rich in insects, especially as regards butterflies, moths,
and beetles; but several of the first-named which have been caught in
Somerset have not been recorded here. The black-veined white (_Pieris
crataegi_), once a common insect, has disappeared within the last forty
years, and the greasy fritillary (_Melitaea Artemis_)--another vanishing
species--is now almost extinct. Neither insect can have been hunted
down for the sake of its beauty or its rarity, and the reason for this
disappearance is unknown.
[Illustration: Spurge Hawk Moth, with Pupa and Caterpillar]
As in the case of birds, the county is, from its position, a favourite
alighting-place for insects coming from abroad. Between 1876 and 1890
large numbers of a very striking and beautiful American butterfly,
_Danais plexippus_, appeared in England, having apparently crossed the
Atlantic, and three specimens were caught in Devonshire. The Lulworth
skipper (_Hesperia Actaeon_), a small butterfly which elsewhere is only
found in Dorset, occurs along the south-east coast of this county. Moths
are very abundant, and the first recorded British examples of several
species were taken in Devonshire.
About a hundred years ago, caterpillars of the spurge hawk-moth
(_Deilephila euphorbiae_) were very plentiful on spurge plants growing
among the sand-hills near Barnstaple. Many of these caterpillars were
taken by naturalists, and were reared, and ultimately turned into
perfect insects; although neither there nor anywhere else in our
island was a wild example of this very beautiful moth ever seen alive.
The spurge plants were long ago covered up by drifting sand, and the
caterpillars were all destroyed. No other locality for them has been
found in England, and as far as this country is concerned the spurge
hawk-moth appears to be extinct.
As might be expected in a district of such varied physical features,
with so mild a climate and such an ample rainfall, the flowering plants
of Devonshire are very numerous, no fewer than 1156 species having
been recorded. The abundance and beauty of its wild-flowers is one
of the characteristics of the county. No one who has ever seen them
will forget the wonderful wealth of primroses in some of the river
valleys--at Holne, for example--or the splendour of the ling-empurpled
sweeps of Dartmoor, or its sheets of golden gorse; or the marvellous
mist of bluebells upon woodland slopes or in the shelter of straggling
hedgerows. Each several district, sea-shore and salt-marsh, moor and
bog, wood and valley, has its own distinct and characteristic flora.
One Devonshire plant, the Romulea or gênotte, _Romulea columnae_, a
Mediterranean species with very small pale blue flowers, is abundant on
the Warren at the mouth of the Exe, but grows nowhere else in England,
although it is found in Guernsey. Several plants occur in only one
other English county; such for instance are the white rock-rose,
_Helianthemum polifolium_, and the Irish spurge, _Euphorbia hibernica_,
which are confined to Devon and Somerset, and the "flower of the Exe,"
_Lobelia urens_, which grows only in Devon and Cornwall. Three plants,
which are very abundant in Somerset, the cowslip, the sweet violet, and
the mistletoe, are rare in this county, although not unknown. The first
plants of sea-kale ever brought into cultivation were originally dug up
on Slapton sands; and the vegetable came into note in Bath about 1775.