BERKELEY

LIBRARY

UNIVERSITY OF
CALIFORNIA

EARTH

SCIENCES

LIBRARY

ISLAND

A R R A N

^ Greenstones, basalt, £&.

GEOLOGY

CLYDESDALE AND ARRAN;

EMBRACING ALSO

THE MARINE ZOOLOGY

THE FLORA OF ARRAN,

WITH COMPLETE LISTS OF SPECIES ;

NOTES ON THE RARER INSECTS OF ARRAN; AND NOTICES OF
ITS SCENERY AND ANTIQUITIES.

JAMES jBEYCE, M.A, LL.D., F.G.S.

LONDON AND GLASGOW:
RICHARD GKRIFFIN AND COMPANY,

'{Publishers to tbe Imbfraty of
1859.

BELL AND BAIN, PBINTEBS, GLASGOW.

EARTH

SCIENCES

LIBRARY

PREFACE.

THE first portion of the following work was prepared in the summer
of 1855, at the request of the Local Committee of the British
Association, then about to assemble in Glasgow. As no connected
account of the Geological formations of Clydesdale at that time
existed, the Committee was desirous that such an outline should be
drawn up as might serve for a guide to the study of the coal series,
of the tertiary formations, and evidences of glacial action, for which
the neighbourhood of the city is so celebrated. To this request the
Author willingly acceded; and to the sketch then printed he appended
a notice of some new views regarding the structure of Arran.

At the request of many friends, who deemed that fuller notices
of the Clydesdale formations would be useful and acceptable, a
new and enlarged edition is now published ; and as Mr. Ramsay's
excellent Guide to Arran has been for some time out of print, an
entirely new account of the structure of this interesting island has
been added, embodying the observations made during many summer
rambles among its romantic glens and mountains. That the work
may serve also as a general Guide to Arran, descriptions of the
scenery and antiquities have been introduced.

Happily, within the last few years Botany and Marine Zoology
have been attracting an increased number of cultivators; and as
Arran is a highly interesting field in these departments also, the
Author considered that their study would be promoted, and the
wants of the student met, by combining an account of the Flora and
Marine Fauna of Arran with that of the Geology. At his request the

M374201

V PEEFACE.

Rev. Dr. Miles, well known to naturalists for his researches in the
Clyde, conducted under the auspices of the British Association, has
kindly drawn up a pretty full account of the more remarkable
creatures inhabiting the Arran shores. To those engaged in scien-
tific inquiries, the complete list of species which he has added,
brought down to the time of his leaving Glasgow for a more impor-
tant sphere of labour in Malta, will prove welcome and useful. The
account of the Flora of Arran has been drawn up by the Author's
eldest son. To Professor Balfour, of Edinburgh, his best thanks are
due for the permission kindly granted to make use of his catalogue
of Arran plants. The list of plants and localities now given has
been thus considerably extended.

The Author has also to acknowledge his obligations to H. T.
Stainton, Esq. of Mountsfield, near Lewisham, whose high reputa-
tion as an entomologist is well known, for the notes which he has
most kindly supplied on the rarer insects of Arran.

In examining the lower members of the coal series in the Campsie
district, the Author was directed and assisted by Mr. John Young,
then of Lennoxtown, now of the Hunterian Museum, Glasgow .
Two of the illustrative cuts in the early part of the work, and many
facts there stated, were supplied by him. Many important facts
were also kindly supplied by James King, Esq. of Levernholm,
regarding the lower coal series. Through the kindness of the Rev.
David Landsborough of Kilmarnock, son of the late distinguished
naturalist, the Author was put in communication with John M'Kin-
lay, Esq. of Bonnington, near Edinburgh ; and from this well known
archaeologist much valuable information has been received. The
accompanying map has been reduced by Messrs. W. & A. K. John-
ston from the Admiralty Survey of 1846. According to Mr. Paul
Cameron, the magnetic variation in the Frith of Clyde at present
amounts to 26° 35' W., with a decrease of 4' to 5' per year, westerly.

GLASGOW, 25th May, 1859.

CONTENTS.

GEOLOGY OF CLYDESDALE.

ART. PAGB.

Introduction: Human Period —

Actual surface — Superficial deposits — Clyde canoes

—Shell beds, 1 1-3 1-5

Tertiary Period —

Raised beaches— Boulder clay—Arctic shells, . 4-9 5-9
Glacial Phenomena —

Scratched boulders — Striated rocks — Roches Mou-

tonnees — Moraines, . . . . . 10-13 9-15

Carboniferous Rocks —

Physical boundaries — Ballagan series and Campsie
beds — Divisions of the Clydesdale coal series, and
sections of strata — Physical geography of the coal

period, „«•.„.• 14-26 15-36

Old Red Sandstone-
Its limits on the Clyde shores — Its cornstones —

Chemical changes by whin dikes, f . . 27,28 36-40
The Old Slates—

Their limits and relations — Plutonic rocks and meta-
morphic action — Theory of the origin of basalt
^•Limestone of the old slates, . . ; . 29-32 40-46

GEOLOGY OF BUTE.

Outline of its Geology —

The slates — Sandstone and coal measures — Ochre
beds and lignites — Singular chemical changes by
trap dikes, .- . ... . . 34-40 47-60

The Cumbraes, . . .* . . 41 60

VI

CONTENTS.

GEOLOGY OF ARRAN.
Physical Features —

Mountain nucleus — Hill ranges — Heights of moun-
tains—Southern plateau, . . . . 42, 43 61-64

Outline of the Geology —

Abnormal position of the granite — Limits of the
other rocks— Coarse and fine granite — Age of
the sandstones, . . . . . . 44-48 64-71

The Outlying Granites—

Ploverfield granite — Granite of Craig-Dhu — Dis-
cussion of the age of the various granites, . . 49-54 71-79
The Trappean Rocks —

Their limits — Mineral distinctions — Dikes — Their

number and range, ...... 55-57 79-84

Glacial Phenomena —

Evidences of glacial action — Dispersed blocks —

Special phenomena of A rran, . . . — » . 58-60 84-91

EXCURSIONS IN ARRAN.

I. To the Summit of Cior-Mhor —

Its advantages as a first excursion — The Brodick
Monolith — Brodick limestone, and section of strata
— Glen Rosa — Granite junction — The Garbh-Alt
chasm — Grand scenery — Dikes of pitchstone and
basalt — Mountain plants — The Ceims — Jagged
outline due to dikes — Summit of Cior-Mhor —
Effects of light, 61-69 92-105

II. To the Corriegills Shore—

The coast sandstones — Dikes of greenstone, clay-
stone, and pitchstone — The great boulder — Scenery
— The Dunfion range, and old fort — Pitchstone
and porphyry— New fossil— Evening aspects, 70-77 106-116

III. To the Summit of Goatfell—

Meaning of the name — Section on the ascent —
Junction at Milldam, and singular dike — Cyclo-
pean walls — View from the summit — Maoldon —
Granite junction— The great Corrie boulder, 78-84 116-123

IV. The Way-side Museum, .... 85 124, 125
V. The North Shore—

Corrie as a centre for excursions — The Corrie
beds — Granite boulders — The Anticlinal axis —
Carboniferous strata, and list of fossils — Uncon-
formable beds at Newton Point — Loch Ranza
Castle— Scenery— Evening at Catacol, . 86-92 126-135

CONTENTS. Vll

ART. PAGE.

VI., VII., VIII. The west coast— Interior of the nucleus
— Return to Corrie — Granite junction and glacial
strise, . . . . .- . 93-95 135-139

IX. The Holy Isle-

Structure — Sandstone and clinkstone — Dikes —
Granite blocks — Shell beds — Legend of St.
Molios, ....... 96, 97 139-141

X. To Windmill Hill and Ploverfield—

Kilmichael — The Hamilton family — Columnar
porphyry, granite, syenite, and sandstone —
Amethysts in sandstone — Bein-Leister Glen, 98, 99 141-144

XI. To Ceim-na-Cailliach and the Castles-

Crystals of smoke quartz — The Carlin's Step —

Grand scenery, 100 144,145

XII. Glen Sannox and Glen Rosa —

Ancient chapel — The Sannox burn — Great dike
on the col — Chasm in the granite — Adders
— The Rosa burn — Singular meteorological
phenomena— The Arran Sabbath, . . 101, 102 145-148

MEMORANDA OF OTHER EXCURSIONS.

The String Road — Craig-Dhu granite — Clachan Glen —
Travelled blocks of fine granite — The Tonnore pitch-
stones — King's Cove — Drumadoon — Blackwater-foot
— The Tormore circles — Leac-a-Breac — Scorodale —
Lag and Benan-head — Kildonan Castle — Dippen —
Whiting Bay — Glacial strias — Pitchstones of Monead-
Mhor Glen, ,. . . . . '. . 103148-156

THE FLORA OF ARRAN.

General views regarding the relations of the Arran Flora

to that of the tracts adjoining, . . .- . 104-107156-164
List of plants, . . . . ... 108164-172

MARINE ZOOLOGY OF ARRAN.

Detailed notices regarding the habits and characters of

the more interesting species, . . . . 109-116 173-190
Complete list of species, with localities, . . . 117191-207

ENTOMOLOGY OF ARRAN.
Notices of rare species, • .... 118 208, 209

NOTICES

GEOLOGY OF CLYDESDALE, &c

FEW parts of Scotland present so rich a field of geological inquiry
as the district of Clydesdale. In none certainly are the facilities so
great for studying the varied phenomena of a large class of forma-
tions. Even within the compass of its capital city, monuments
exist of many successive revolutions in physical geography and
organic life ; beneath her streets are entombed the remains of a vast
extinct creation ; the foundations of her teeming warehouses and
crowded quays are laid amid the mouldering works of a Primeval
Race ; while between these extremes there is interposed a long series
of terms indicating a progressive advance towards the existing forms
of animal life and aspects of the surface. Of scarcely less interest
are the shores of the noble Frith, which present a complete suite of
the older formations ; while among its islands Arran has long been
celebrated as exhibiting a greater variety of geological phenomena
than perhaps any other tract of like area on the surface of the globe.
In the following pages a few brief notices are given of the various
deposits, their fossil contents, and the best points for studying the
relations of the strata, in order to direct the researches of future
inquirers, and to aid those who are beginning the study of the science.

I.— HUMAN PERIOD.

1. The city of Glasgow stands on the great coal field of Scotland,
about seven miles from its north-west border. Within its bounds the
several "measures" of this formation, sandstone, shale, clay, iron-
stone and coal, crop out in many places ; but the surface is generally
covered with newer deposits. The site of the smaller portion on the
south side of the river is a level plain, composed of ancient estuary

B

or fluviatile accumulations. A narrow strip on the north, through-
out the whole length of the city, is of the same character. North
of this, the ground rises with considerable rapidity in a series of
elliptic-shaped hills, from 100 to 250 feet above the plain, their longer
axes being parallel to the course of the river, here west-north-west.
The principal heights are Garngad hill, 252 feet 6 inches ; Necro-
polis, 225 feet; Garnethill, 176 feet 7 inches; Blythswood hill,
135 feet 3 inches ; Woodlands hill, 153 feet ; Billhead, 157 feet ;
Observatory, 179 feet 5 inches ;* Jordanhill, two miles west, 145
feet. Some of these were originally a little higher, the tops having
been levelled to afford a broader space for the erection of buildings.
The elevations give a pleasing variety to the city, and afford striking
views of the distant Highland mountains, and the fine amphitheatre
of nearer hills, which close in on all sides, except the east, the un-
dulating and well-wooded basin, intersected by the lower course ot
the Clyde.

2. Apart from deposits now in progress, the latest formation is that
of the estuary and fluviatile accumulations above referred to. These
are spread out continuously on both sides of the river, but more
widely on the south side, from Butherglen, three miles above
Glasgow, to near Erskine, ten miles below it, — the former being the
upward limit of the tide before it was obstructed by works connected
with the improvement of the navigation, — the latter the termination
of the river in the estuary, and the limit of the ascent of salt water.
The deposit consists throughout of laminated beds of sand and loam,
with thin courses and streams of gravel and layers of peat. Marine

fa a} Carboniferous beds; (b b) Till and lower sand beds; (c) river Clyde, (d d) post-pleiocene, or raised beaches,-
(ef) estuary deposits of the human period.

shells have been found sparingly in its middle and lower parts, and
a few fresh water species in the upper beds ; but no collection has
been formed of these interesting objects, so that we cannot describe
the fossil contents more minutely. The deposit has been tranquilly
formed throughout, long periods of repose having been but rarely
interrupted by floods. Ancient rude canoes have been found in
various parts of it, deeply embedded in the sand and loam, one at

* These heights are given on the authority of Mr. Thomas Kyle, Civil Engineer

3

either end of the area, and a great many on the banks of the river at
Glasgow; some at heights 10 or 12 feet ahove the highest level
reached by the greatest floods on record in the Clyde. Eespecting
these, the following particulars have been kindly furnished by John
Buchanan, Esq., the well-known archaeologist of this city, who
carefully noted at the time the circumstances attending the discovery
of those more recently foundj —

" Within the last eighty years, no less than sixteen of these interesting
remains of aboriginal workmanship have been found in and near Glasgow.
They are all, with one exception, formed of single oak trees, in some in-
stances by the action of fire, in others by tools evidently blunt, probably
of stone, and therefore referable to a period so remote as to have preceded
the knowledge of the use of iron. The first known instance was in 1780.
The canoe lay under the foundations of the old St. Enoch's church, at a
depth of 25 feet from the surface — that is about the level of low water in
the river below Argyle Street — and within it was a stone hatchet of
polished greenstone, in good preservation. It is now in the possession of
C. Wilsone Broune, Esq., of Wemyss Bay. The second, in 1781, while
excavating the foundations of the Tontine, at the Cross, the surface being
here 22 feet above high water. A third, in 1824, in Stockwell Street, in
a deep cutting opposite the mouth of Jackson Street. The fourth was
found, in 1825, in the cuttings for a sewer in London Street, on the site of
the ' Old Trades' Land : ' the canoe was vertical, the prow uppermost,
and a number of shells were inside. The next discovery was made in 1846,
when the improvements in the river began to be actively carried out.
Eleven canoes were discovered in a short period. Of these, five were
found on the lands of Springfield, opposite the lower portion of the
harbour ; five more on the property of Clydehaugh, west of Springfield ;
and one in the grounds of Bankton, adjoining Clydehaugh. The ten were
in groups together, 19 feet below the surface, and above 100 yards south
from the old river bank, which was then where the middle of the stream
now is. The twelfth canoe was brought up by the dredging machine, on
the north side of the river, a few yards west from the Point House, where
the Kelvin enters. The Erskine specimen was found in 1854. It was
taken out by Mr. Taylor, who has charge of the ferry, nearly entire. To
test its capabilities, he had it partially supported on a raft, and floated in
it across the stream.

" A collection of these canoes is now preserved in a building in the
College grounds ; and single specimens may be seen in Stirling's Library,
Miller Street ; the Andersonian Museum, George Street ; ferry house,
Erskine ferry, ten miles below Glasgow ; and in the hall of the Society
of Antiquaries, Edinburgh."*

* Mr. Buchanan has since published a very full and interesting account of these
curious remains in Glasgow Past and Present, vol. iii.

3. The conclusion is forced upon us by these facts that the entire
area was at a remote time covered by an estuary, connected with the
sea by a narrow strait near Erskine, where the hills on either side
press close upon the stream ; whose limits reached inland almost as
far as Johnstone and Paisley, narrowed upward by the projecting
Ibrox and Pollokshields ridges, but again widening out, so as to
wash the base of the Cathkin and Cathcart Hills, and sweeping round
north-east in a wide bay, so as to cover the space now occupied by the
Glasgow Green and suburbs of Bridgeton. The river then entered
about Bothwell or Butherglen ; and the northern shore was formed
by the lower slopes of the hills already alluded to, and their contin-
uations north-west by Partick, Jordanhill, and Yoker to the vici-
nity of Erskine. At even higher levels within the city Mr. Robert
Chambers has traced well-marked terraces, which he considers the
beaches of a former sea ; and as far up as near the summit level of
Sauchiehall Street, about 25 paces west of the Wellington Arcade,
a marine deposit with shells was discovered in 1850, and described
by Mr. William Ferguson.* The beds were, sand 2 feet; peat
1 foot, and sand again not passed through ; whole depth, 9 feet.
In the inferior sand bed there were marine shells, but specimens of
troclius ziziphinus only were preserved. The height above high
water is here 94 feet 8 inches, and is the greatest at which recent
marine deposits are known to exist within the city. Whether this
bed is a remnant of the extensive estuary deposit above noticed it is
impossible to say, nor is it of much importance to inquire, as recent
shelly deposits exist in the basin of the Clyde at like and even much
greater elevations, in situations which we cannot suppose to have
been continuously occupied by the estuary in question, and whose
origin is certainly very different, far removed from the human period
to which the canoe beds are referable. Even this era — the " stone
period" of Scottish archaeologists — lies far back in pre-historic time —
how far we have no means of knowing. Nearly 2,000 years ago
the Roman wall was constructed between the Forth and Clyde —
from Bowling to Grangemouth ; and, as Mr. Smith of Jordanhill
has happily pointed out, no oscillation in level has taken place since
that time. This singular work had precise reference even to the
present tide levels. How remote, then, must be the time when the
quiet waters of the estuary laved the hill sides, now covered by busy
thoroughfares ; and a race whose other memorials are lost navigated
in these rude canoes the broader waters of the river, whose narrowed

* Transactions of the Philosophical Society of Glasgow, vol. iii., p. 147.

stream now floats the largest ships, and brings to our doors the
choicest products of the globe.

Mr. Robert Chambers, in his interesting and prettily illustrated
work on " Ancient Sea Margins," has some judicious observations on
the connection of these deposits with those of other parts of Scot-
land, especially in the estuaries of the Forth and Tay, pp. 206-208.

II.— TERTIARY PERIOD.

4. The beds just described overlie towards their margin another
series, occupying a peculiar place, and presenting a marked organic
sequence, which links on the tertiary age to the existing order of
things, and affords another amid the now oft-recurring examples of
passages from group to group, which almost defy classification, and
show us how past creations shade off into the present, continuously,
without a chasm. The deposits in question are well known to geolo-
gists as the Clyde Beds, the discovery of which, with an interesting
account of their natural history, we owe to Mr. Smith of Jordan-
hill. According to his classification, they are as follows, in descend-
ing order : —

1. Post-Pleiocene, or Raised Beaches.

2. Pleistocene, Newer Pleiocene, the Till, or Boulder clay of the glacial

period.

3. Sands, gravels, and clays, resting on the Carboniferous formations or

on the overlying trap rocks.

Post-Pleiocene, or Raised Beaclies.

5. When we pass from the river Clyde into the frith at Dum-
barton, both shores are seen to be marked by a well defined
terrace, 10 to 20 feet above the present tide level, and bounded
inland by a steep cliff. The Greenock railway, from the Bishopton
tunnel to Greenock, runs along this terrace ; and it is equally
well defined upon the Cardross side, from the Leven mouth by
Helensburgh to Gareloch-head. The watering places of Gourock,
Kempoch, and Ashton, and on the opposite side that of Kilcreggan,
stand upon it. In Roseneath peninsula it is extremely well defined
and traceable round the whole shore. Everywhere, indeed, upon
the shores of the Frith and its islands the same terrace is
clearly marked ; nor less so on the west coast, from the Crinan canal,
by Oban, up the shores of Loch Linnhe, on Loch Fyne, &c., and
along it in most parts of these shores the coast road is carried. The
cliff, which bounds it inland at a distance varying from a few yards,

6

as on the north shore of Arran, to a quarter of a mile, and even half
a mile, as in parts of the Eoseneath and Renfrewshire shores, is every-
where sea- worn, and hollowed out into caves ; the terrace is covered
with shingle greatly sea-worn ; it is flat and difficult to drain ;
the elevation seldom passes 40 feet; usually it is considerably
less. Mr. Smith was the first to point out that at the level
which the land then had — for it is the land that has been raised, and
not as Mr. Chambers would explain the appearances, the sea that
has subsided — it must have stood for a much longer period than that
which has elapsed (2,000 years) since the Eoman works in this
country were constructed. The great length of the caves, of which
Professor James Nichol has given a remarkable instance on Davar
island at Campbelton* — as well as other cases of wearing, such as the
projection of the harder veins in the rocks, the overhanging of the cliffs,
&c., clearly prove this. In these caves and on the terrace, sea-shells of
species now existing in the adjoining sea, occur abundantly and in
many places. An interesting case at Kothesay was published in the
Witness, July 1855, by Dr. Hugh Miller. One of the most re-
markable as regards elevation which has come under the notice of
the writer of these memoranda is the steep terrace at Eoseneath
house, a seat of the Duke of Argyll, which is shown in the annexed
cut. The heights were kindly furnished by Mr. Lome Campbell of
Eoseneath.

(a) Upper slopes, on which the offices stand i (b) Sea-worn cliff of old red sandstone, called Wallace's lov.pi
(c) Terrace of former beach, on which JZoseneath house stands,- (d) Sea level,

The upper terrace is 79 feet high, the lower north portico of
Eoseneath house 42 feet ; shells broken and mixed with sea- weed are
found on both terraces, 2 or 3 feet below the surface ; on the upper
terrace in hollows 68 feet above high water. The bed in Sauchiehall
Street, Glasgow, is probably of this age, though somewhat higher
(Art. 3) . At Johnstone, near Paisley, a case is mentioned by Mr.
Smith, in which sea-shells, bones of fishes and sea-birds, claws of crabs,
and sea-weed were found at about 80 feet elevation, resting on Till beds
70 feet thick. The brickfields about Glasgow and Paisley abound in
these shells ; in the neighbourhood of Jordanhill the beds are 80 feet
above the river, the shells being almost always at a considerable

* Jour, Geol. Soc., vol. viii., 1852.

depth ; — 30 feet in some cases mentioned by Mr. Smith. The
Paisley fields are to the north-west of the railway station ; they yield
a good many species. At Dalmuir, north of Erskine, a shelly deposit
described by Dr. Thomas Thomson* has yielded 70 species. Beds
on the east shore of Lochlomond, two miles north-west of the mouth
of the Endrick, and 10 feet above the highest level of the lake ; also
beds at the south-east angle of the lake, and on the summit of Inch
Lonach island opposite Luss, gave to Mr. Adamson about 12
species. f Captain Laskey found 22 species four miles from Glasgow,
in cuttings of the Paisley Canal, 40 feet above the level of the
Clyde. J The age of these beds has not been accurately determined ;
it must depend upon the proportion of Arctic species ; but they seem
referable to the upper or post-pleiocene division. Space does not permit
an enumeration of other cases, of which several might be mentioned
at much greater altitudes, though not in the vicinity of Glasgow.
The shells are generally of a littoral character, much worn and broken,
and about 160 species have been noticed. Of the same age and con-
nected with these are many sand, gravel, and clay beds without shells.

The Boulder Clay.

6. This remarkable deposit, whose original mode of formation has
excited such active discussion among geologists, was long since
noticed by Col. Imrie, Mr. Bald, and other writers, as the old alluvial
cover spread out over the surface of the coal fields and trap rocks of
Scotland. § But it is to Mr. Smith we owe its establishment as a
definite group, with peculiar organic contents. || It may, perhaps, be
best divided into three subordinate groups : 1st, upper Till, with finer
and smaller boulders than those of group No. 3, of lighter colours, and
unstratified ; 2d, stratified beds, in which chiefly the shells and other
remains occur ; and, 3d, the lower Till, resting frequently on the car-
boniferous rocks, and consisting of stiff blue or red clay, confusedly
mixed with boulders, and unstratified. In the Till proper, shells are
rare, and when found, fragmentary ; but the stratified beds have yielded
a great number of species, and of these from 10 to 15 per cent, are
either extinct or not now known in the British seas. Those which
are recent, but not found in the British seas, occur in the Arctic
regions, and indicate therefore the existence of a colder climate than
that of the present period, and colder also than that under which

* Rec. Gen. Science, i., 131. f Wern. Mem., iv., part ii., 334.

\ Wern. Mem., iv., part ii., p. 568.
§ Ibid, several vols.

|| Ibid, viii. Proceed. Geol Soc., ii., 427 ; and iii., 118, 149. Trans. Geol Soc.,
vi., 2d series, p. 153. Jour. Geol Soc., ii., 33 ; v., 17,

3

the post-pleiocene, or raised-beach formations were accumulated.
The shells are generally entire, even delicate specimens being in
good preservation.

The deposit may be studied in almost any deep cutting; and
shells occur in many localities. One of the richest lies along the south
shore of the Kyles of Bute, opposite the Burnt Isles. Here a stream
on the Bute side has cut into the deposit, and exposed the shells.
Mya udevallensis, a boring shell, is in its natural upright position ;
25 species were found. Another rich locality was a bed on the side
of the railway between Port-Glasgow and Greenock, 50 feet above
the sea level. The shells were in a series of thin beds of sand, gravel,
and clay, resting on the lower boulder Till of unknown thickness.
Here Mr. Smith found 33 species. Over the shell bed were, sand 10
feet ; coarse gravel 2 feet ; and vegetable soil.

7. The following is a list of the shells of the boulder clay not found
in a recent state in the British seas, kindly supplied by Mr. Smith.
The entire number he estimates at 151 : —

Tellina proxima : Arctic seas.
Astarte multicostata.

Propinqua.

Withami : Bridlington : Arctic seas.

Borealis : Upper Crag : Arctic seas.

Mya udevallensis : Arctic seas.

Pecten islandicus.
Leda oblonga.

antiqua.

Cytherea laevagita.
Mactra striata.
Natica clausa.

Smithii (Bulbus, Brown).

fragilis.

glaucinoides.

Nassa Monensis.
Buccinum striatum.

granulatum.

Trochus inlatus (Margarita undulata, Sowerby ?) : Arctic seas.

Littorina expansa : Arctic seas.

Velutina undata : Arctic seas.

Fusus peruvianus : (Murex, Sowerby) : Crag, Udevalla ; Arctic

seas.
Fusus imbricatus : Arctic seas.

curtus.

Saxicava sulcata, Udevalla.
Balanus udevallensis, Udevalla.

8. These are not the only remains, however, yielded by the beds in
question. Those of mammalia now extinct in these islands have also
been found. Mr. Bald found an elephant's tusk in the excavation of
the Union Canal, 28 miles from Glasgow, in the west park of the

.Clifton hall estate.* Elephants' bones and tusks were found
near Kilmarnock and at Kilmaurs, in Ayrshire, in strata which
Professor William Couper and Dr. Scouler examined and pro-
nounced to be the Till. At Kilmaurs a few sea-shells were associated.
At Chapel Hall, near Airdrie, the late Mr. John Craig discovered
elephants' remains in the upper Till, at an elevation of 350 feet above
the sea. These interesting specimens are preserved in the Hunterian
and Andersonian Museums, at Eglinton Castle, and in the Museum
of the Royal Society of Edinburgh. In the spring of 1855, Dr. A.
Beveridge, of Glasgow, found in a deposit of this age, near Bishop-
briggs, a portion of an elephant's tooth, which is preserved in the
Hunterian Museum.

Beds Mow the Till

9. The sands, gravels, and clays (No. 3) below the Till occur
rarely ; the Till generally resting on the carboniferous rocks. The
only locality in which they have yielded shells is that described
by Mr. Smith ;f it is the highest in Scotland at which shells have
been as yet discovered, namely, the surface 524 feet and the shell
bed 510 feet. The locality is near the Monkland Iron Works, 14
miles south-east of Glasgow. The few shells found were of the
same Arctic character as those in the Till.

III.— GLACIAL PHENOMENA.

Scratched Boulders.

10. The boulders from which this deposit receives one of its
designations are distributed largely through its entire mass, but
generally of greater size in the lower portions of the beds. They
consist of rocks which are found only to the north - west and
west of Glasgow ; and the same holds true with respect to the
loose surface boulders which are found over Clydesdale. These have
thus travelled up the river basin in a direction contrary to that
of the present drainage, or action of that force which might in
some cases be conceived adequate to the transport of at least the
smaller ones. They cover all rock formations alike, being found
along the summits of the trap ranges of Lennox and Cathcart, on
both sides of the basin, as well as over its interior and less elevated
districts. When we pass westwards of the coal tracts, into the dis-
trict where Devonian and primary rocks prevail, we find that the
transport has not been mutual ; that region has received no boulders
from the basin of the Clyde, though the limestones, sandstones, and

* Wer. Mem., iv., 58. f Jour. Geol Soc., vi., 386, 1850.

C

10

other " measures," with the trap rocks overlying, are sufficiently hard
and coherent to have withstood the attrition of a lengthened journey.
So numerous and varied are the contents of the boulder or Till beds,
that within the limits of Glasgow, from the cuttings in the hill
sides for the foundations of the houses, nearly a complete collection
of Scottish rocks may be made; — granite, gneiss, mica, clay and chlo-
rite slates, quartz rock, porphyries, old red sandstone and conglo-
merate, coal sandstone, ironstone, limestone, and a vast variety of
traps are all turned out from the same cutting. The recent exca-
vations on Woodlands' hill for the roads and buildings of the new
park have exposed such assemblages ; a noted locality, which excited
great interest during the meeting of the British Association in
1840, and has been often since referred to, is Bell's park, near the
Caledonian Railway station, north side of the city. The great ma-
jority of these boulders are rounded and smooth, but many of them
are striated and grooved ; and when the covering of Till is removed,
the rocky bed on which it rested has also been found in several cases
to present the same scratched and grooved surface. A good ex-
ample occurred in Bell's park ; but the rock has been quarried.
In the neighbourhood of the Town's Hospital some of these striated
blocks may still be seen. Many were turned out from the cuttings
for the roads and buildings of the new park.

1 1 . Grooved and scratched rocks were observed near Glasgow by
Colonel Imrie in 1812 (Wer. Mem., ii., 36), and ascribed by him, and
by subsequent observers, to the action of the rocks on one another
during transport by currents of water sweeping the surface; and
were classed under the head of Diluvial phenomena, being supposed
to have been produced by the Deluge, or several successive floods
in different periods. About 1840, however, they began to be re-
ferred to the action of glaciers, or the agency of floating masses
of ice, which carried the boulders, grinding them down and marking
the surfaces across which they passed. Mr. Smith's remarkable
discovery of Arctic species in the Clyde shelly deposits associated
with Till and boulders is strongly corroborative of this latter
view, and indicates a prevalent low temperature immediately
preceding that condition of things during which the British
seas were furnished with their existing testacea. To this view
the opinions of geologists now chiefly lean; but the subject is
yet beset with difficulties. Several considerations must be carefully
attended to; — the impression of the surface markings must have
been posterior to the rounding process — the far transported masses
are the most rounded, and there seem evidently several periods
in the Till deposit, as already noticed. May it not hence be sup-

11

posed that great undulations in the waters under which the coal
strata were deposited produced by earthquakes or other elevating
forces, which gradually converted the area into dry land, were of
such energy and long continuance as to tear up and re-arrange the
rocky materials on the bottom — to sweep off great bodies of strata,
forming such valleys of denudation as that of Campsie and Lennox-
town — on opposite sides of which the strata exactly correspond —
and that the deposits so formed were subsequently modified by the
action of floating ice, or the surface moulded by glaciers after the
whole area was converted into dry land ? Icebergs we know are only
formed along the sea borders of land covered with glaciers. Such
ice-covered land must therefore have existed along the north-west of
Scotland, presenting a bold coast towards the south-east, whence the
bergs floating off through a deep sea, deposited their rocky load as
they melted below and were capsized, or as they stranded on the tops
of sunken ridges. Thus huge masses of mica slate were left on
the summits of the Pentlands and Lennox hills, and the whole basin
of the Clyde strewed with the spoils of the Grampians, to whose
eastern flanks, as an old sea border, we are thus enabled to track back
the course of the floating bergs. The blocks are often so remarkably
grouped that we can almost mark the spots where successive icebergs
were stranded. The writer of these notices has seen in many of the
glens descending upon Loch Long from the west and north-west
successive assemblages of granite blocks, as many as 200 within a
circular area of 30 yards diameter, with long intervening spaces
almost destitute of them. The masses increase in magnitude as
the granite nucleus whence they emanated is approached ; and as
the glens become narrower and the hill sides steeper, the crowd
of blocks is so great as almost to fill the valley, while the rocky
sides exhibit grooved and polished surfaces and roches moutonntes
in great perfection. In the same district are many striking
examples of perched blocks. At heights varying from 1,200 to
1,800 and perhaps 2,000 feet, and on the slopes of mica schisfc
mountains so steep that one cannot descend but by a zig-zag course,
granite blocks are lodged but slightly in the thin soil, on narrow
ledges or terraces in considerable numbers, and of all sizes up to those
whose weight was carefully estimated at 1J tons. Towards the bot-
tom of the valleys some were estimated at 13 to 15 tons. Across
the deep hollow occupied by Loch Long, up the sides of the hills on
the east side, and across the rugged and high ridge dividing it from
Loch Lomond, trainees of such blocks may be followed. Near
Arrochar, east side of Loch Long, they are abundant and of great
magnitude. These facts indicate a vast amount of submergence

12

during the drift period. Cases still more striking as regards eleva-
tion have been lately noticed by Professor Ramsay. He finds drift
with shells on the mountains of Snowdonia at heights of 1,800 to
2,300 feet.*

The shores of Loch Lomond present many isolated boulders of
granite, but few are of such enormous size as above stated. These
phenomena, however, come under a large class, belonging to general
geology, and need not be further referred to. It may merely be
remarked with reference to the remains of the extinct quadrupeds
(Art. 8), that they seem to point to the existence of a warmer climate
than the present, and to present evidence of a kind opposite to that
afforded by the Arctic testacea. The state of the remains of the ex-
tinct quadrupeds shows that, though associated with rounded gravel
and far transported blocks, they belong to animals which must have
lived not far from the places where the remains are found ; and that
their destruction may have been caused by a sudden submergence,
and a sweeping of the surface by diluvial currents. But that the
climate was warmer does not necessarily follow ; since elephantoid
remains occur abundantly in North Siberia and Arctic America, in
such a perfect state of preservation as to show that the creatures
were fitted for a cold climate, and as everywhere in the British isles
these remains occur in association with existing quadrupeds and tes-
taceous species.

Striated Hocks — Roches Houtonnees.

12. Local examples of scratched and polished rocks may be
noticed here in connection with the scratched boulders of the
Till. Perhaps the finest instance to be seen within a short dis-
tance from Glasgow is the summit level of the pass between the
Gare Loch and Loch Long, 600 feet high, and about two miles
from the village of Gareloch-head, fully described by Mr. M'Laren ;
Ed. Phil. Jour., xl. to xlii. Mica slate rocks are here finely striated
in a direction nearly from N.W. to S.E. The rocks on the road-
side in several places, from this point to Gareloch-head, exhibit the
same markings. They may be seen also at the landing-place at
Row, and at several points on both shores of the Loch, where they
extend under the sea. But at none of these points are there any
striking examples of polishing, nor of that peculiar " Moutonnee"
(rounded and bossy) character which is elsewhere exhibited, as at
Parson's Green, near Edinburgh, described by Mr. R. Chambers,
and Jacob's Wood, near Stavely, Westmoreland, described by the

* Jour. Geol. Soc., vol. viii.

13

author of these memoranda ; and a case at Ulverston, noticed by
Professor Phillips, but not yet described by him ; all of which
were under a drift covering, and as perfect and finely shown as
any case yet noticed in Switzerland.* The shores of Loch Lomond,
however, exhibit tolerable examples. At Rowerdennan Inn, between
the house and shore, there is a good example of striation and
rounded rocks. The surfaces are remarkably worn, rounded and pol-
ished; and the striation about parallel to the axis of the lake. Other
cases of striation occur in many places along the shores. Mr. James
Thomson, civil engineer, now of Belfast, lately noticed a good case
on sandstone rocks, about three miles from Glasgow, south-east of the
road between Auldhouse and Thornliebank, Pollokshaws, and due
south of the manse near Auldhouse ; the direction was here oblique
to the road, or running nearly west. Captain Brickenden has de-
scribed f striations on the rock of Dumbarton Castle, 150 feet
above the river, in the fissure intersecting the rock from north to
south. The surface of the sandstones on Craigmaddic moor is
striated in many places, the direction being nearly E. and W. ; and
the trap rocks forming the high ridge between Strathblaiie and
Milngavie are similarly marked, in a direction declining a little S.
of E. ; while they exhibit also rounded and bossy surfaces in great
perfection. Fine examples may be seen in Corrie Glen, about one
mile west of Kilsyth. Here a vast accumulation of detrital matter
with travelled boulders is exhibited in a natural section on the
banks of the West burn, as shown in the annexed cut.

(a a) River bank of detritus, with travelled and striated boulders; (b b) great intruded coulee of
basaltic rock, enclosing (c) a shale bed, altered to the state of a coarse opal.

The south bank rises to the height of about 80 feet, and is
entirely composed of detritus, partly local and partly derived from
rocks existing only in situ to the westward. The most remarkable

* Phil. Mag., Dec. 1850; and Brit. Assoc. Rep., 1850.
f Journ. Geol. Soc., vol. xi. (1855).

14

blocks which we noticed were two of large size and rhomboidal
form, — one of the Campsie " main limestone," and another of green-
stone,— showing deep striation and grooving on one side, that on
which they must have rested while borne along upon a hard surface.
We shall have occasion to refer again to this interesting section.

Moraines.

13. On entering the Argyllshire Highlands from Glasgow, at
almost any point, masses of detritus are met with, filling the glens,
obstructing their entrance, and backing up against the hill sides
in flat terraces, with steep fronts towards the river. The glacialists
early fixed on these, and all such accumulations in the Highlands,
as moraines of the various orders, terminal, medial, and lateral;
and not a few have been so described. Mr. Charles M'Laren
has published an account of a remarkable one in Glen Messan, a
glen entering the valley of the Holy Loch from the west, which
he considers a true case of an ancient moraine, such being, accord-
ing to his view, comparatively rare in Scotland.* Mr. Robert
Chambers, who is somewhat sceptical on the subject of ice as
viewed by Mr. M'Laren, coincides with him in regarding this glen
as a true seat of moraines. Another case given by Mr. M'Laren is
one mile south of Strachur on Loch Fine. One may be seen at
Coruisk, near the mouth of the main glen ; another about three miles
farther up at Stronlonaig, on a glen entering from the south. The
shingle bed at Row Ferry, Roseneath, is fixed upon by Mr. M'Laren
as the terminal moraine of a glacier which he supposes to have once
filled the Gareloch, crossing from the Loch Goil mountains by the col
or summit level, where the scratches are seen. To us this appears a
true shingle bank formed by the sea, owing to the peculiar move-
ments of the tide at this part. The material is completely sea worn ;
and the outlet being narrow, and the extent of water inside great,
the tide flows with a powerful current, there being a stream on the
west side both at ebb and flood, and an eddy on the eastern. The
fact pointed out to me by Mr. Smith of Jordanhill, that the shingle
bed rests upon the old boulder clay or supposed glacial deposit,
and must therefore be of later date than the rock striation and
boulder transport, seems decisive as to the nature of this bank.
Other cases of moraines will be found noticed in a recent paper by
Mr. Chambers, t

* Edin. New Phil Jour., vol. i., new series, p. 189, 1855, and vols. xl. and xlii., 1846,
1847.
f Ed. Phil. Jour., new series, i., 97.

15

In the island of Arran, the northern portion of which might be
expected, from its peculiar structure, to be favourable to the growth
and seaward extension of glaciers — if such ever existed in Scotland
— we have failed to discover any very decided case. The rocks of
the granite nucleus are certainly unfavourable to the preservation of
surface markings. At the head of Glen Sannox, however, there are
some fine examples of smoothed and polished rocks, and traces of
lateral moraines on both sides of the glen. Finely marked gravel
terraces occur at the mouth of Glen lorsa, in front of the Duke
of Hamilton's lodge, — they have flat summits and steep sides, and
are elevated far above the action of any existing cause. Similar
terraces in Glen Catacol, and mounds at the mouths of Glen Eosie,
Clachan Glen, and others, may be deemed moraines by some. They
are, perhaps, rather due to the action of currents sweeping these
glens, when the area was rising from beneath the sea. The only case
of striation noticed was in the south section of the island, near the
waterfall in Glen Aisdale, two miles west of Whiting Bay. The rock
is a tough close-grained greenstone ; and the striation and grooving
are in a direction from west-south-west, slightly oblique to the valley,
which runs nearly east and west. Nowhere, however, are the phe-
nomena of surface boulders more strikingly exhibited. They occur
along the eastern shore in prodigious numbers and of enormous size,
somewhat larger in proximity to the granite nucleus ; but still of
huge proportions at Corrygills, and Whiting Bay, three to eight miles
from the parent rock ; and over the interior of the island, they strew
the surface at all altitudes.

IV.— CAEBONIFEEOUS EOCKS.

14. The carboniferous system of Scotland, which attains so vast
a development in the basin of the Clyde and adjoining tracts,
presents some peculiarities and departures from the normal type,
as exhibited in England and Ireland. The entire area occupied by
the coal measures is, in the geological sense, but a single basin, with
the sole exception of a limited area to the extreme south-east, to
be presently noticed. Across the broad zone which reaches from
St. Andrews and Dunbar on the east, to Ardrossan and the heads
of Ayr on the west, the older rocks, on which the coal measures-
repose, nowhere rise to the surface so as to form "independent basins."'
Eidges of trap rocks do indeed intersect the area in various directions,
but cannot be said to cut it off into distinct basins. The coal tracts-
of the Forth are continuous with those of Clydesdale, while the
latter are confluent with those of Eenfrew and Ayr, — at either

16

extremity the coal beds rise from beneath the sea. The area is thus
a great synclinal trough, filled with an enormous thickness of coal-
bearing strata. The permian and triassic rocks are rudimentary, and
there is no great body of carboniferous limestone at the base of the
series, as in most other countries ; and this constitutes a second
peculiarity of the Scottish field. The boundaries are formed through-
out by Devonian rocks, which attain an enormous development along
the north-west border ; but on the south-east form a narrow and in-
terrupted zone, so that trap ridges and dikes alone, in many parts,
cut off the coal strata from the great southern tract of silurian rocks.
Limestone, with all the usual fossils which characterize the carboni-
ferous period, does indeed occur, but not as a well developed and
continuous base ; nor has the millstone grit of England been hitherto
established as a member of the Scottish series. It may yet be
found possible to prove its existence within the area ; and at a still
lower level, certain sandstones and shales on the line of junction
with the undoubted old red sandstone, may turn out to be on the
true horizon of the lower carboniferous limestone. The Ballagan
beds seem to us to be such a peculiar group, though by some they
may be regarded as the uppermost portion of the Old Bed series. —
They occur in fine typical development, in the bed of the Ballagan
burn, at the base of the waterfall called the Spout of Ballagan,
about three miles N.W. of Lennoxtown. They here present a
vertical section of about 100 feet in height, and consist of numerous
alternations of blue and red shales, calcareous marl, white and red
thin-bedded sandstones, and thin courses of limestone. The lowest
bed visible is a coarse dark-coloured sandstone containing sedge-like
plants resembling calamites, but without joints ; the highest, a thick-
bedded yellow sandstone without plants, stretching in below the trap
series which extends to the hill tops. The plants must, however,
exist in the middle portion of the section, for they occur abundantly
in the fallen blocks which strew the river bed throughout. A vein of
gypsum, 9 inches wide, and numerous contiguous strings of the same
substance, stretch far up the cliff, crossing nearly at right angles the
various strata, which have a uniform N.W. dip at an angle of 11°.
The only fossils met with in this locality are these sedge-like plants,
which seem all to belong to one species, and are insufficient to decide
the age of the beds. A group of veiy similar character occurs on the
east side of the Leven valley, near Dumbarton, in the glens N. and
N.E. of Dumbuck hill ; and here a few fish scales have been found,
but in so fragmentary a state as to render the species doubtful. The
locality is, however, promising, and a careful search for fossils will
probably bring species to light which will decide the question, and

17

determine the true horizon of the carboniferous formations on this side.
The strata are almost an exact counterpart of those at Ballagan, bufc
of greater thickness, and seen in more marked superposition to the old
red sandstone which here rises northward, forming the outer part of
the Kilpatrick hills. This is the western limit of these beds ; from
Ballagan they sink rapidly eastward, their upper portions being
seen. in Finglen and Campsie Glen ; beyond which they are overlaid by
the sandstone forming the floor of the Campsie valley. About one mile
west of Ballagan they are again seen in the bed of a stream above
the village of Strathblane ; and still farther north, in Spittal Glen,
running up N.W. towards the base of Drumgun hill, they are finely
exhibited in several sections, graduating imperceptibly into the beds
of the true Old Red. Two great faults here traverse both series, and
throw down the Ballagan beds quite out of position. At the head of
the glen the latter are directly covered by the basaltic rocks forming
the hill tops. The old red sandstone, from this point north wards, is
continuous with the great band on the Highland frontier. Through-
out the entire district of Lennox, from Dumbarton to Stirling, the
geological horizon is greatly obscured by the disturbances attendant
on a prodigious outburst of igneous rocks, forming all the higher
portions of the hills, and descending in some parts in broad streams
into the low country at their base. Such a coulee of basaltic rock
crosses the high ground between Strathblane and Milngavie, cutting
right through the coal measures, which are tilted up by it on the
west part of Craigmaddie Moor, and separating them from the cor-
responding measures of the Duntocher district, which reappear in the
same relative position as in the Campsie valley, in consequence of an
immense fold, or dome-shaped arrangement of the strata. This coulee
will be intersected by a tunnel nearly three miles in length on the line
of the newGlasgow Water Works. In the neighbourhood of Castlecary,
Kilsyth, and Croy, similar outbursts and streams of igneous matter
occur, altering the coal strata, and in some places bearing them up
with it, so that the seams are worked on the hill tops, and in anticlinal
beds along their flanks. An elevatory movement due to this cause,
producing an anticlinal axis in the centre of the valley below the
" spout," has given to the Ballagan beds their actual position ; at
least, it is only by such a supposition that we can explain their
situation and their relations to the strata on the south of the valley,
or north-west of Craigmaddie Moor. A conical hill of prismatic
trap, called Dunglass, above 200 feet high, rises from the centre of
the valley, immediately below the section which has been described

above.

D

18

15. The annexed cut (N.W. to S.E.), the lower portion of which
on either side of the hill (/) is partly conjectural, represents the

probable relations of the strata at this highly interesting point.
Here (a a) represents the trap of the hill tops, (b b) yellow sand-
stones, the highest members of the Ballagan series ; (6' b') probable
position of the same beds south of Dunglass hill ; (c) the Ballagan
beds ; (d) a trap dike ; (e e) probable position of the lower portion
of the Ballagan series on either side of the axis ; (/) Dunglass hill
composed of prismatic basalt, and forming the anticlinal axis of the
strata and watershed of the valley ; (g h) coarse gritty sandstones
higher in the series than the yellow sandstones (b b) ; (k) thick
bedded fine grained sandstones, forming the highest parts of Craig-
maddie Moor to the west. The beds of this latter dipping S.E.
form the floor of the Campsie valley, on the level of the Grlazert
rivulet.

16. The yellow sandstones (b b) at the top of the Ballagan section
thin out eastward, and disappear in Campsie Glen, so that the trap
here rests directly on the beds (c), or true Ballagan series, which is
depressed in this direction, and covered by newer deposits, whose
elevated edges, as they successively crop out N.W., are overlaid
along the side of the north hill by tabular masses of trap. The
south hill, forming the opposite side of the valley, is a perfect coun-
terpart of the north, save that the overlying trap is absent. The
strata correspond exactly ; and this rich and beautiful vale, through
its extent of five miles in length by half-a-mile to a mile in width,
owes its peculiar features to the action of powerful denuding forces,
probably coinciding with the elevation of the area, at the close of
the glacial period, as already indicated (Art. 11.) On account
of the great interest of this case, and the economic value of the
strata, we subjoin a section representing the principal beds on both
sides. The less important members of the series and the faults, with
minor irregularities, are omitted.

19

$

20

The main limestone (e) is of marine origin, and has many remains.
The white limestone (/) is of fresh-water origin, and almost made
up of remains of cypridce, a family of crustaceans. The sandstone (g)
is that represented in the preceding cut as forming the higher parts
of Craigmaddie M'oor, in consequence of its gradual rise to the west.
The alum strata are mentioned farther on.

17. The subdivisions of the Coal series, as given in two papers hy
the late Mr. John Craig, mining engineer and geologist, one published
in the Transactions of the Highland Society, vol. xii., or vol. vi.,
New Series, 1839, the other laid "before the British Association in
1840, have not since been disturbed, and are generally received as
approximately correct.

The entire series may be divided as follows : —

1. Upper Bed Sandstone series.

2. Upper or fresh-water coal series.

3. Upper marine series.

4. Lower coal series.

5. Lower marine limestone series, with intercalated fresh-water

beds.

6. The Ballagan series and Old Eed Sandstone, at the base of

the entire formation.

The first of these divisions has been considered to represent the
New Eed Sandstone series. It occurs in the higher part of the
central district, about Hamilton, Blantyre, &c., and consists of
variegated sandstones and marls, with a few thin coal seams, and
traces of plants ; and hence it seems hardly proper to place these
beds in the New Eed series ; but they have been as yet only partially
examined, and it may hereafter appear that the uppermost beds
really represent this formation in a rudimentary state.

The upper coal series is of fresh-water or estuary origin. It reaches
from Glasgow due east by Garnkirk, north side of New Monkland
parish, towards Bathgate. South-west its west ooundary runs from
the trap hills at Dychmont by Drumpeller, Bellshill, Motherwell,
and Larkhall to Stonehouse ; thence by Carluke, east and north-east
towards Bathgate ; thus comprehending all the central fields in the
parishes of Camnethan, Shotts, Dalserf, Dalzell, with Old and New
Monkland. Limestones are absent, and are represented merely by
calcareous sandstones. The entire thickness is about 220 fathoms.
The testacea are all of fresh-water or estuary genera, as unio, anodon,
mytilus, &c. ; fish remains, and the usual coal plants abound. There
are nine beds of coal, whose aggregate thickness varies from 24 to
34J feet, and twenty-five minor seams, rarely passing 14 inches each,

21

The first workable bed, or Ell coal, is 45 to 50 fathoms below the
upper red sandstone of the first division ; the fifth bed is a splint
coal, and below it the remaining seams are less continuous, and of
inferior thickness. There are, besides, numerous beds of common
clay ironstone and blackband, a variety which contains enough car-
bonaceous matter to effect its calcination ; and this is usually done
at the mouth of the pits. The blackbands vary in thickness from
4 to 22 inches. There are three principal bands ; the upper, 14
inches thick, is 24 fathoms above the Ell coal, and is worked in Old
Monkland parish. Another, the mussel band, the second in descend-
ing order, is very remarkable as being almost entirely made up of
fresh-water shells, which are seldom found in the clays above and
below this ferrugineous band. It is 14 to 22 inches thick, and is
worked near Airdrie. This blackband is 16 fathoms below the splint
coal. The lowest bed is of the same quality, but lies much lower in
the series. With the other beds similar shells are associated ; and
in Ayrshire the same fresh-water coal series appears, with rich black-
band ironstones. The area occupied in Lanarkshire by this upper
coal series is about 20 miles long, and from 6 to 15 broad.

18. Immediately north of the Necropolis hill, Glasgow, and
along the line of the Monklands canal, this fresh- water series reposes
upon limestones, shales, and- sandstones abounding in marine remains,
orthoceras, encrinites, bellerophon, euomphalus, nucula, productus,
spirifer, &c., and constituting the upper marine group. It contains
two seams of coal 12 and 14 inches thick, and irregular beds of iron-
stone ; total thickness, about 600 feet. North of Glasgow, across
the high ground between Bishopbriggs and Cumbernauld, the sand-
stones are of great thickness, and the " measures " are without coal.
— Below these beds succeeds the lower coal group without lime-
stone, but with several blackbands, and beds of coal, of which the
lowest is a cannel coal, 2 to 3 feet thick. These coals and iron-
stones are worked north-west of the Kelvin, at North Woodside,
Jordanhill, &c. At the bottom of the whole group are nodular clay
ironstones, and thin limestones. — The lowest group yet established
reaches from this horizon to the Ballagan beds, and contains marine
limestones (main limestone 4J feet thick), alum shale, and sulphureous
coal, 4 to 6 feet thick ; below which are other limestones and coal
beds, alternating and intermixed with tufaceous trap, to the bottom
of the series. At Hurlet, Duntocher, Campsie, &c., these limestones
and shales are well seen. The alum works at Campsie, on the south
side of the valley of denudation already alluded to, have been long
established in connection with the shale bed. These works embrace

22

a greater variety of manufactures than any other in Scotland, in this
department. The aluminous shale, or "alum till," lies between the
sulphureous coal below, and main limestone above, and is no more
than from 2 to 3 feet thick. There is first (ascending) an aluminous
band containing iron pyrites, and passing in some parts of the mines
into an imperfect blackband ironstone. Over this is the "gentle
slate," or principal aluminous band, 6 or 7 inches thick. The
uppermost band, called the " diamond" bed, from being studded with
crystals of pyrites, is much poorer in aluminous matter and is seldom
used, except to mix with the first or pyritous band. The main lime-
stone rests on this band in the mines ; but westwards on the south
hill the aluminous strata thin out, and the limestone then reposes
upon the sulphureous coal. On the north hill the shale bed is 15 feet
thick ; but the lower portion only is aluminous, and much poorer in
the "ore." The strata, however, are an exact counterpart of those
on the south hill. The upper part of the shale on the north hill is
charged with multitudes of marine shells. — The chief difference at
Huiiet consists in the more equal distribution of the aluminous matter
throughout the whole thickness of the shale ; but there is over the
limestone a thick stratum, called the dough or duff bed, rather poorer in
sulphur than the alum schist. The schist here shows, when effloresced,
long brittle crystals of sulphate of magnesia ; which are rarely met with
in the Campsie ore. After the underlying coal is wrought out, the
alum schist decomposes under the action of the air, exfoliates and
falls down. Its sulphur, by the action of oxygen, combines with the
metallic bases, forming sulphates. When decomposition is complete,
the mass has the appearance of flock silk. The schist in this state
is taken from the coal wastes and lixiviated in stone cisterns. The
liquid is then evaporated to the proper density, and receives the por-
tion of muriate or sulphate of potash necessary to its formation into
the state of a crystallizable salt. This forms the sulphate of alumina,
or alum of commerce. Of late years this salt has been developed by
slow combustion in long ridges, coated with the exhausted ore;
which is found a quicker process.

The extraordinary mass of coal at Quarrelton, near Johnstone,
which attains a maximum thickness of 90 feet, but is generally 50
to 60 feet, seems to belong to these lower divisions. It lies in a
basin-shaped cavity, less than 1 mile in diameter, and consists of 5
distinct seams, separated by thin layers of shale, sandstone, or iron-
stone. Over the coal is a stratum of sandstone, 24 feet thick, and
this is covered by blue basalt, 100 feet thick. This prodigious mass
of coal, perhaps the thickest ever found, seems to have originated

23

either in vast quantities of vegetable matter, swept into some shel-
tered hollow in the original estuary, or in a horizontal displacement,
which has thrown several contiguous beds over one another.* The
strata are displaced by two faults, one throwing the beds down 30
feet, and the other 50, in a direction nearly vertical.

19. The inferior marine groups appear to the south, south-east and
south-west of the fresh-water series, and descend in the usual alter-
nations to contact with the old red sandstone along the borders in
that direction. To the south-east of this border, in Lesmahagow
parish and adjoining tracts, a small coal field occupies an isolated
position, cut off on the one hand from the Clyde basin, and on the
other from the Ayrshire fields, by ridges of Devonian rocks, amid
which igneous products are variously intercalated. The strata of the
Glenbuck field rise up over a ridge of 1,000 to 1,200 feet high, pass
down into the basin of the Douglas, a tributary of the Clyde, and
rest on a narrow band of old red sandstone, which cuts them off from
the Lesmahagow field ; the latter is separated from the Clyde fields
by a similar band to the north-east of the village of Lesmahagow,
and stretches out east to near the base of Tinto. The strata are
extremely well exhibited in natural sections, and contain a complete
suite of fossils of true carboniferous types. " The coal shales, sand-
stones and ironstones, afford similar remains in abundance ; and there
can be therefore no doubt that the coal of this field is of the same
age as that of the Clyde basins. It is worthy of remark, that seve-
ral species of Trilobites occur in the shales and limestones, far up in
the series ; that a white grit, resting on one of the lower limestones,
contains a prodigious quantity of fish remains, and corresponds appa-
rently with the great ' fish bed' of some English fields ; and that
from one of the middle shales a fossil has been obtained agreeing ex-
actly with the Serpulites longissimus of the Silurian System, pi. v.,
fig. 1. The field contains fifteen seams of coal, whose thickness varies
from 2 feet to 15 feet, the aggregate amounting to about 65 feet
of workable coal. There are black band and clay band ironstones,
the principal seam of the former averaging 11 inches ; but neither
these nor the coal beds have yet been worked to any considerable
extent, owing to the greater accessibility of the fields farther down
the Clyde." f Here, as in other districts, the alternations of lime-
stone and the other measures already noticed descend to the horizon
of the Old Eed, on which the whole series reposes, without the inter-

* See Niccl's Geology of Scotland, p. 99, for an illustrative cut, copied from Williams'
Mineral Kingdom, vol. ii., p. 319.
t See Brit. Assoc. Rep., 1850, p. 77.

24

vention of any large body of limestone — a peculiarity worthy of notice
in all the coal fields of central Scotland. The entire phenomena of
this field are highly instructive.

20. The varied phenomena of these interesting fields maybe studied
to advantage in many natural sections. The Lesmahagow field
through its whole area, and along its borders, is completely opened
up by glens and deep water channels, which exhibit the succes-
sion of the strata and many remarkable faults. The banks of the
Nethan, Calder, and other streams which pursue rapid courses from
the high uplands into the profound synclinal trough traversed by the
Clyde downwards from the Falls, and the banks of the Clyde itself,
present many instructive sections and most favourable localities for
collecting fossils. The fresh-water series, across the central area, is less
completely exposed, and is best known from interior workings and
boring journals. The marine series is laid more fully open. It
reaches out on either side to the base of the hill ranges bounding the
area; and these, composed of igneous rocks, erupted through the
coal formation, or along its outer margin, bear up the various "mea-
sures" on their flanks, and bring them to day in deep glens and the
banks of mountain burns. In the Lennox range we have, already
mentioned the Auchinreach and Spittal glens, opening respectively
into the Leven and Strathblane valleys ; the Ballagan, Finn, and
Clachan glens, descending into the vale of Campsie, near Lennox-
town ; these expose the subjacent Old Red, the intermediate Ballagan
beds, and the lower members of the coal formation. Farther east
there is an interesting section of beds somewhat higher in the
series — one of the most instructive in the wrhole Clydesdale basin, and
to which the attention of the student cannot be too emphatically
directed. We refer to the succession of beds laid open in the middle
portion of Corrie glen, one mile west of Kilsyth, as shown in the
following cut.

The strata here exposed lie between two streams descending from
the high trap ranges to the N.W., and uniting farther down before
entering the valley of the Kelvin. Of these the West Burn, the
upper portion of which is represented in the sketch of Art. 12, cuts
most deeply into the soft shales and sandstones which are finely
shown in a nearly vertical section. Workings on the economic
strata farther favour the researches of the student.

The strata belong to the lower marine series. The yellow sand-
stone (ri) at the base is higher than that of the Campsie valley, and
the two limestones (g) and (/), respectively 3 and 5 feet thick, are
also superior to the Campsie main limestone. The shale beds (/*)

are from 52 to 60 feet thick. The section is from N.W. to S.E. ;
and the general dip is S.E. at a small angle. Organic remains abound
throughout the whole series of beds, and are readily obtained even
from the limestones. The principal are many beautiful corallines,
some very rare; many species of productus, spirifer, terebratula,
orthoceras, bellerophon, goniatites, &c. The shales contain large
mityli, nuculae, &c. The remarkable effects of igneous action in this
glen will be noticed farther on.

(a) Shale with ironstone layers; (b) shale with encrinites; (c) thin bedded yellow
sandstone ; (d ef) thick beds of calcareous shale with limestone bands ; (g) main lime-
stone; (h~) shale with nodular limestone; (i) coal bed; (_/) shale; (k) shale with marine
shells and corah; (I) coralline limestone; (m) shale with ironstone bands; (n) thick
bedded yellow sandstone ; (o) thick shale beds with ironstone bands ; (p) boulder clay —
seep. 13.

21. We subjoin several journals of borings in these lower marine
beds, in order to show the general correspondence at remote points, as
well as the local variations of the deposits. No. 1 gives the strata
on the South hill, bounding Campsie valley in that direction ; No.
2 the beds lying in the valley, to be regarded as a continuation
of No. 1. They are not presented in any natural section, and seem
to lie between the Ballagan beds and the strata of No. 1 ; the sand-
stone on the floor of the valley forms the passage from the one series
to the other. A portion of the beds in No. 1 is well seen in Craigen
glen, opening southwards towards the village of Torrance ; and these
abound in organic remains, among which, in addition to the genera
above mentioned, are lingulse, and many fish teeth and scales. The
boring No. 3 is taken from a pit sunk at the E. end of the South
hill, and on the S.E. side of a great greenstone dyke which crosses
the district from N.E. to S.W., and throws down the beds on the
side of Campsie valley, to a considerable depth. They are higher in
the series than any in the Campsie district. In the language of the
miners, "blaes" denotes all pure shales ; " fakes," laminated sandy
shales ; " kingle," hard siliceous bands ; " doggar" beds are bands of
shale with nodular clay ironstone.

No. 1. SECTION or STRATA PASSED THROUGH IN SINKING A PIT NE^
THE SUMMIT LEVEL OF THE SOUTH HILL, 450 FEET ABOVE TH
LEVEL or THE RIVER GLAZERT.

Fath. Ft. Inch.

Sandstone, thickness not

Fath. Ft. In<

White limestone (fresh-water), 0 4 (

known.

Kingle, ... .04

Blue shale, . 11 1 0

Shale, ... 11'

Ironstone band, 007

Limestone (marine), . 0 0 1(

Blue shale, . 322

Fakes, ... 0 0 11

Black limestone, 100

Alum schist, . . 0 0 5

Shale, with 4 bands iron

Parrot coal, . 00'

stone, . 100

Common coal, . . 0 0 1(

Blue shale, . 22 2 0

Fire clay, in two beds, parted

Limestone (marine), 040

by kingle, . . .126

Alnm cr»V»iQ+ 090

/iluill bCnl>L j » • \J & V

Coal, . . . .038

46 2 t

Under clay, . . .007

No. 2. JOURNAL OF BORE PUT DOWN AT BURNHOUSE, NEAR TH

LEVEL OF THE GLAZERT.

Fath. Ft. Inch.

Fath. Ft. In

Surface earth,

107

Hard shale, ... 0 3 (

Sandstone,

109

White freestone, ..02

Very hard band,

010

Kingle, .... 1 0

Fire clay,
Fakes, .

018$
018

Gray fakes, ... 0 1
White freestone, ..21

White kingle, .
Hard shale, .

046
158

Fireclay, ... 0 2
Light fakes, ... 0 2

Fakes, .

0 I 6

Kingle, .... 0 1

Fire clay,

0 0 11

Fakes, . . . .01

Impure limestone,
Shale, with stripes o

ffake

039

s, 1 4 6

White kingle, ... 2 4
White marble band, . 1 1

Blue shale,
Ironstone,

0 1 7$
003

Fire clay, ... 0
Blue shale, ... 0

Shale, .

007

Light shale, ... 0

Coal,
Fire clay,

0 0 11

0 1 2£

Shale, with stripes of fakes, 0
Kingle, .... 0

Fakes, .

106$

Fakes, .... 0 0

Kingle, .

007

Shale, .... 1 0

Limestone,
Shale, with stripes o

ffake

0 0 8i
s, 1 4 10$

Shale, with stripes of fakes, 0 0
Kock not known, ..00

Shale, .

Oil

Limestone, ... 0 1

Blue fakes,

007$

White freestone, ..01

Shale, . ,

0 1 ll

Light fakes, ..01

Ironstone,

003

Kingle, . ..00

Shale, .

004

Light fakes, ..00

Coal,

012

Kingle, . ..14

Fire clay,

021$

Light fakes, ..01

Fakes, .

1 0 10$

Light kingle, ..03

Impure limestone,

0 1 10$

Shale, .

155

Depth of this bore below the

White kingle,

0 2 10$

level of the valley, . 33 0

No. 3. JOURNAL OF STRATA PASSED THROUGH IN SINKING A P

FOR COAL ON THE GROUNDS OF BALQUARHAGE, NEAR CAMPSIE.

Feet,

Fe

Surface earth, with clay and boulders, 7
Blue shale, with marine shells, . 42
Shale, with encrinites and trilobites, 3
Shale passing into milestone, . 1

Shale, with ironstone nodules, '
Dark soft shale,
Black shale, with doggars,
Bituminous shale,

Culmy limestone, in two beds, . 8
Calcareous shale 1
Bituminous shale, .... 2

Coal, not very good,
Dark sandy shale, full of coal measure
plants,

Dark blue shale, .... 2

—

27

No. 4. ECONOMIC STRATA or LANARKSHIRE, COPIED FROM

SECTION MADE OUT BY DR. BANKINE, AND MR. JOHN
KERR OF CASTLEHILL.

Fathoms under
New Red
Sandstone.

32 Upper coal.

41 Cone in cone limestone.

52 Ell coal.

56£ Fresh-water limestone.

63 Pyotshaw coal.

64£ Main coal.

78 Splint coal, with band of clay ironstone above it.

86 Mussel band ironstone.

88 Sour milk coal.

93£ 1st Black band ironstone.

108 Virtue-Well coal.

114 2d Black band ironstone.

118 Mussel band ironstone.

124 Castle hill 1st coal.

133 Castle hill 2d coal and ironstone.

144 Kiltongue coal.

164£ Drumgray coal.

177 Coal (no name given in section.)

190 Crofthead coal and ironstone.

200 Slaty ironstone.

220 Thomson's ball and gin ironstone.

235 Curdley ironstone.

254 Gare limestone.

282 Belstone limestone.

308 Climpey limestone.

325 Carluke 1st coal.

326| Carluke 2d coal.

335J Tower coal.

342 Four bands clay ironstone.

347 Gas coal and black-band ironstone.

370 Lingula ironstone.

380 Lingula limestone

381£ 1st Kinshaw limestone.

384| 2d Kinshaw limestone.

390 1st Culmy limestone.

to 397 Rae's gill ironstone, 11 bands.

399 Hosie's limestone.

415 2d Culmy limestone.

418 Main limestone, under a band of clay ironstone.

419 Coal under main limestone.
424 Limestone.

434 Shelly limestone.

440 Oyster limestone.

450 Scabricula ironstone.

465 Old red sandstone.

The preceding section, No. 4, contains the economic strata only
of the upper portion of Lanarkshire. It was prepared for the
meeting of the British Association in 1855 by Dr. Kankine of

28

Carluke, long well known for his profound and accurate acquaintance
with these strata and their fossils. The first 235 fathoms give the
fresh-water series ; below this, from the Grare limestone down to the
oyster limestone, inclusive, there are 13 beds of marine limestone :
and among these, the beds 418 and 419 are the equivalents of the
Campsie main limestone and coal ; and the Campsie strata generally
are represented by the beds from the Kinshaw limestone (381^),
inclusive, downwards to the old red sandstone. In the Campsie dis-
trict, all the beds above the Kinshaw limestone are wanting ; and
the Ballagan beds have no representatives in the Carluke district.
The Ballagan series does, however, occur in the S.E. coal field on the
Merse of Berwick, as we are informed by Mr. Stevenson, and indica-
tions of them have also been noticed on the borders of the East-
Lothian field.

22. Sections very similar to the preceding are obtained around the
borders of the district, amid the series of lower strata; but it is
impossible to identify the beds except in a very general way, as
great analogous groups of limestones, shales, ironstones, and coals ;
and viewed in this way the Carluke series, so carefully made out by
Dr. Rankine, is typical of the entire lower deposits. The lower
coals are generally of inferior quality, but good ironstones descend
to the very base ; while limestones, usually marine, occur in oft-
repeated alternations with the other measures. A general resem-
blance exists, but the local exceptions are remarkable. The Campsie,
Duntocher, Carluke, and Hurlet series have been referred to already
as illustrating this similarity. At Whiteinch near Partick, a little
above the level of the Clyde, a bore of nearly 300 feet gave 11 beds
of limestone, varying in thickness from 8 inches to 8 feet, aggregate
about 30 feet ; eight bands of ironstone, in all about 5 feet, but no
coal seams. At Maxwelton near Paisley, a bore of 200 feet gave
neither limestone nor ironstone, but several good coal seams,
aggregate thickness about 14 feet. At Goldilee near Houston, on
the outer margin of the Renfrewshire fields, where they come
against the trap associated with the old red sandstone of the Coast
Range, among the strata passed through in a shaft of 110 feet deep
were two limestones 8 feet apart, and respectively 7 and 4 feet thick,
and four coal seams about 6 feet in all, but no ironstone. At Kaims-
hill on the same border, a little south of Lochwinnoch, the limestones
and coals are similar, but good ironstone bands are associated. At
Howwood near Castle Semple, 125 feet of shales and rich iron-
stones overlie a bed of limestone 10 feet thick ; and three miles S.E.,
at Braidstane near Beith, there occurs the largest body of lime-

29

stone in the West of Scotland. The following section shows the
order and thickness of the strata : —

Feet. Feet.

1. Surface soil, . 16. Coal, . * ... .1

14 7. Slate clay, . . . .6

2. Limestone, full of marine fossils,

3. Fire clay, ....

4. Limestone, ....

5. Clay indurated, .

Limestone, with few fossils, . 18

9. Coal, 1

10. Slate clay, not passed through, ?

The strata are traceable for a mile in the line of bearing, but the
breadth is limited in the direction of the dip. They crop out towards
the north in the direction of the great outburst of trap, already
noticed as forming a mineral axis in this region, in connection with
the old red sandstone, through which it has been erupted.

23. On the subject of these local variations, and the prevailing
similarity among the local groups, Mr. Montgomery of Cloak has the
following remarks respecting the fields of Kenfrew and North Ayr,
in his clear and accurate outline of the geology of these tracts :* —
" The different strata alternate in no definite order, while no one of
them seems essentially necessary to the formation of a coal field.
Even coal itself may be awanting, whilst all the other strata
usually found in a coal basin are there. The place usually occupied
by freestone or slate clay is occasionally filled by ironstone. Lime-
stone is as capricious in its presence or absence as any other of the
measures ; nor is it possible even to define its limits in the district
under consideration. It makes its appearance here and there, more
particularly upon the edges of the coal fields ; but its continuity from
one place to another where it is seen is by no means certain. In
various places it has been wrought out, perhaps indicating that the
quarries had been opened in masses detached by some convulsion
from greater strata. But whatever hypothesis may be adopted re-
garding this matter, none favourable to the opinion of the limestone
strata holding a necessary place in the coal measures of Renfrew and
Ayr can be entertained. If the strata of limestone were ever con-
tinuous, they certainly are not so now ; and to support the opinion
of their former continuity, a much more intimate acquaintance with
their numerous organic remains would be necessary, than it is sup-
posed that any one has yet acquired."

24. We do not know that these remarks, penned twenty years ago,
need any modification at the present time, with all the knowledge
we have since acquired respecting the organic remains of these beds.
They support the opinion already advanced, upon evidence furnished
by other districts of our great coal tract, that there is no great
persistent body of "carboniferous limestone" separating by a well
marked horizon the "upper" from the "lower" coal measures, and

* Jour. ofAgricul. and Trans, of Highland Soc., vol. xliii., p. 441, 1839.

30

that the millstone grit also finds no place in our series. In England
and Ireland the development is more complete, and the lines of
division more strongly marked. The mountain limestone is an
important formation, and widely persistent in both countries ; and in
England the millstone grit, overlying the limestone, in most cases
fully developed. In Ireland it is less universal, and its thickness is
much less. In Scotland, on the other hand, the millstone grit has
not been identified ; and as to the mountain limestone, we may
almost say that it is, as it were, split up into numerous bands ; and
strata of shale, coal, ironstone, and sandstone, intercalated among
the separated members. The mineral type differs widely ; but the
organic remains are identical throughout the two series. They are
thus of one age, but formed under different conditions of the ter-
restrial surface which adjoined. An ancient sea channel filled the
space already described (Art. 14) as forming the great synclinal
trough in which lie our coal strata. Warm and humid lands
stretched far and wide to the N.W. and S.E. ; they nourished a
luxuriant vegetation of tropical or sub-tropical species, and were
drained by large rivers emptying into this common receptacle.
Like the tropical rivers of our own era, these were subject to sudden
and violent floods, which swept away the exuberant vegetation and
spread it widely over the bottom of that ancient frith. Sand and mud,
mixed with peaty matter, produced by decomposition in sheltered
situations, were the river sediment, in an incalculable disproportion
to the trees and plants carried down. The calcareous matter, sus-
pended in small proportion in these turbid waters, formed, by
chemical segregation, subscrystalline beds of limestone of trifling
thickness and limited horizontal extent. Under peculiar circum-
stances existing in particular spots, the purity of the water and a
lengthened period of repose favoured the growth of a few corals, and
the rearing of pigmy coral banks from the bosom of that primaeval
sea. In the region of the ancient Earth which we now call Ireland,
the conditions were widely different : the whole interior, to two-thirds
of the present area, was occupied by the waters of an inland sea or
gulf, as large as the Aral Lake. Around its shores on all sides rose
high ridges of granitic rocks and silurian slates, breached in a few
places by narrow straits, uniting it to the ocean outside ; and its
surface was varied by a few islands of elongated form, less elevated
than the bordering land, but formed of rocks of the same old types.
The pure and warm waters of this archipelago were tenanted by
myriads of rock-building polypi, whose ceaseless toil through long
ages reared up from its still depths numerous reefs of coral ; while
the high temperature of the waters favoured the prolific growth

31

of other coralline species, and the development of chambered
cephalopods (nautilus, orthoc&ras,) to an enormous size, bearing to
the Scottish species somewhat of the same relation as do the
Tridacnas of the Eastern seas to the dwarfish bivalves of our north-
ern latitudes. The suspended lime, calcareous sand formed of
triturated coral, and the countless myriads of testacea, zoophytes,
and other creatures with which the waters teemed, united in forming
vast deposits of limestone with a prevailing crystalline structure
rarely found in the limestones of this age in Scotland.

Conditions very similar to these prevailed over large tracts in the
centre and North of England, where the formation follows the crys-
talline type, and has less of that mechanical character which marks
the Scottish deposits. Yet are the fossils most markedly alike
throughout these groups in the three countries, and all are evi-
dently of the same age. We speak, however, rather of the lower
groups, the carboniferous limestones of England and Ireland, and
the shale and sandstone beds with coal and ironstone seams, in Scot-
land. The upper portion of the Scottish series is, we have seen, of
fresh- water or estuary origin, and formed under different conditions ;
while the upper portions of the Irish series perhaps differ in age from
both the others, and in amount of development are far less complete.

25. For Fifeshire and the Lothians, Mr. Page has recently*
given a classification very similar to that set forth by us, but some-
what less minute, and perhaps on that account to be preferred in
the present state of our knowledge. Founding his deductions upon
his own inquiries and the published reports of Mr. C. M'Laren, Sir
D. Milne Home, and Mr. Cunningham, he arranges the strata in
the following order : —

" 1. True coal measures — consisting of numerous alter-
nations of coal, shales, sandstones, ironstones, and occa-
sional beds of impure limestone, . . -~ . . . 2,500ft.

"2. Several strata of crinoidal and productus limestone,
with intervening beds of shale, sandstones, and thin seams
of coal, ... . .180ft.

" 3. A vast thickness of whitish fine-grained sandstones,
bituminous shales, a few thin seams of coal, mussel-bands
or shell-limestone, and fresh-water limestones abounding
hi cyprides, . . . . • , • • • 1,500ft.

" In this instance there is no development of millstone grit, the
whole system resolving itself into upper coal, mountain limestone,

* In his excellent " Advanced Text-Book of Geology," a work remarkable for accu-
rate and clear statement and sober generalization, and adorned by many eloquent
passages.

32

and lower coal How far these subdivisions may indi-
cate great life-periods, or only portions of one great epoch, has yet to
be determined by a more minute and rigorous comparison both of
vegetable and animal species, — a task which has hitherto been
neglected for the lighter labour of popular description and attractive
generalization."

The second group in this arrangement corresponds to Nos. 3 and
4 in our division (Art. 17) ; the third corresponds to our fifth, and
in it there occur, as with us, intercalated beds of fresh-water origin,
consisting chiefly of a mass of cypridae. Our sixth group, the
Ballagan series of beds, finds no representative in the eastern fields,
though occurring, as already noticed, in a state of less perfect devel-
opment in the Merse of Berwick. But to constitute the middle
portion into a separate group under the designation of " the moun-
tain limestone," appears to us only calculated to mislead the student,
and to give a false impression to geologists regarding the true char-
acters and great distinctive feature of our lower groups. Thick
beds of marine limestone occur at the base, in the middle, and at the
top of the series, and contain the same fossils ; while at each end of
the series, fresh-water strata are intercalated among the prevailing
marine groups.* The entire series of beds thus forms one great
natural group of strata, uniform throughout in the character of its
often repeated alternations of similar bands of rock, and in its
organic contents. Its prevailing character is that of a mechanical
deposit, the crystalline limestone bearing an incalculably small ratio
to the shales, sandstones, and impure earthy limestones. Yet is
this entire series the representative of the great crystalline masses
at the base of the coal formation in England and Ireland. The
whole group seems to us to be in the place of the mountain lime-
stone ; but this rock nowhere exists as a base or geological horizon.
This view was first, we believe, put forward at the Edinburgh
meeting of the British Association in 1850, but met with con-
siderable opposition, and has since been often canvassed. Mr. Miller
remarks regarding it as follows :f —

* The marine limestones of the Lennoxtown valley, and white cyprida limestone (/),
have been already noticed (Art. 16). Mr. John Young of Lennoxtown also finds a
fresh-water limestone among the marine beds at Bishopbriggs ; and very recently
(March, 1857), Mr. John M'Diarmid of Glasgow has found within the city, south side
of Parliamentary Road, opposite the Town's Hospital, beds of limestone and calcareous
sandstone, with numerous marine fossils of the ordinary genera, and fossil plants, at the
very top of the marine series, and closely adjoining the fresh-water series of our second
division (Art. 17).

f " The Fossiliferous Deposits of Scotland," being an address to the Royal Physical
Society of Edinburgh, delivered November 22d, 1854. Pp. 16, 17.

33

" There are lew finer sections of the coal deposits anywhere in
Britain than those laid open along the shores of Granton, Mussel-
burgh, and Prestoupans ; and the section of the mountain lime-
stone exposed in the ravine at Dry den, is, as far as I have yet
seen, the most extensive in Scotland. By those who hold, as is
done by some of the geologists of our Western capital, that this
formation is wanting as a base to the Scottish coal field, a visit to
this section might be found very instructive. It does not exhibit
that great thickness of limestone for which the corresponding
formation in England is so remarkable, but presents for several
hundred feet together, in its encrinal bands, intercalated amid shales
and sandstone, evidence of a marine origin ; and its upper calcar-
eous beds, laden with spirifers and producta, and of very considerable
thickness, show that a tolerably profound sea must have covered the
field shortly ere the formation of our older beds of workable coal."

These remarks, however, hardly impugn the statements already
put forward ; this limestone is not at the base ; its thickness is
not great ; and its encrinal bands are intercalated among shales and
sandstones, which contain the same fossils. The sea was indeed
deep ; but it was not a sea of coral reefs, nor of pure chemical de-
posits; its waters, by means of frequent floods, were widely dis-
coloured by vast irruptions of black mud, and red or white sand,
with which calcareous matter was sparingly mixed ; and thus the
whole deposit is of one age, while the limestone is truly, from its
fossils and mineral character, the same as the mountain limestone,
though not en masse in the same position. The shales and sand-
stones, with its separated portions intercalated among them, represent
in all particulars the great English formation, underlying tJie coal.
—What a long series of changes and vast lapse of time are implied
in the elaboration of these strata in the bosom of the primaeval
ocean ! Its deep bed was often laid dry, and on the desiccated sur-
face lakes were formed, which became the abode of cyprides and
other fresh-water genera. These conditions so long prevailed, and
the individuals continued to exist in such countless myriads, that
thick and widely continuous beds of limestone were accumulated
from their exuviae. Again the area subsided to a small depth,
the sea found an entrance, and a thick coal seam and shale beds
with marine remains were deposited. A continued subsidence to an
enormous amount succeeded, and a vast series of shales and sand-
stones, and a few seams of coal and beds of limestone, charged
throughout with a prodigious variety of marine fossils, were slowly
accumulated. Again, by some mighty internal convulsion, a new

F

34

aspect was given to the region, most probably that of a wide archi-
pelago, in whose winding channels and on its little elevated lands,
was formed a new series of alternating marine and fresh-water
strata, almost a repetition of those far down in the series. To ex-
plain the origin of the upper portion of the marine series, the thick
body of strata ranging north of Glasgow and across the higher
portions of the city, we must again suppose the existence of a sea
of considerable depth, receiving an abundant and very mixed sedi-
ment, and the waste of a prolific land vegetation of a tropical or
sub -tropical character. The close of this period was marked by the
elevation of large tracts along the margins of the area, and the
formation of a lake or estuary filling the central and depressed
portion, now occupied by the upper or fresh-water coal series already
described in Art. 17. The climate remained unchanged, and the
vegetation then attained its maximum of development, resembling
more that of a tropical jungle or river-delta, than anything now seen
in our latitudes. Then began that remarkable series of changes in
repeated depressions and elevations of the bottom and margins of
this lake or estuary, which geologists have often attempted to
chronicle, in describing the physical geography of the coal period.
These are much the same in Clydesdale as in other coal tracts, and
we need not here attempt the description. We may observe, how-
ever, that the underclay, or floor of the coal, generally exists in our
fields, roots being often seen passing down through it ; and that
ranges of upright trees have been met with at several levels amid
our coal measures. These underclay s and seats of the trees point
out the successive surfaces on which the vegetation flourished, and
which, though perhaps slightly depressed, cannot have been far
below water ; the coal seams are a sort of rude chronometer indi-
cating the time occupied in the deposit, while the interposed sand-
stones and shales show the amount of depression which took place
before the surface was again fitted for the growth of plants. This
series of changes was continued through vast periods of time, till
at length the rich storehouse was furnished with those materials
which were destined, in the providence of the Creator's goodness,
to contribute to the wants and happiness of Man, when he should
be called into being upon that theatre, already the scene of the
creation and extinction of many races which had served their
purpose and disappeared. — But the series of revolutions was not
yet completed. The entire area, with portions of its borders, was
again submerged to a depth probably exceeding 300 fathoms ; the
strata were fractured and dislocated in all directions, and successive

35

streams of volcanic matter were poured out from the heated interior.
These spread out among the beds in sheets, pierced them through
n dikes, and were accumulated over them in great mountain masses.
The succeeding revolutions by which the existing aspects were
^iven to the surface have been briefly sketched in the preceding-
part of these notices.

26. With regard to the distribution of these igneous products
.t is remarkable that they have been chiefly erupted along the
Doundary of the Devonian and carboniferous rocks, from Ardrossan
;o the mouth of the Eden, in the Coast Range, the Lennox, Ochill, and
•Jidlaw hills, so nearly continuous with one another, as to be sepa-
•ated only by the channels of the Clyde, Forth, and Tay. This
ine is parallel to the principal axis of the Grampians, which were
elevated at an earlier period ; and is also in the direction followed
>y the many earthquake movements recently experienced in Scot-
and. There is also evidence of elevatory movements in connection
vith another band of these rocks near the border of the primary
Highland tracts.* On the south border of the coal districts there
s also an extensive development of these rocks ; and they constitute
everal considerable ranges within the area, as the Fereneze and
^athkin hills separating the Ayrshire fields from those of Lanark
,nd Renfrew, the Bathgate hills, and other lesser ridges. The
iuge trappean mass of Tinto, and the varied igneous products of
he Pentlands seem to belong to an older era. That the trap
anges on the borders, and within the area, were erupted since the
leposition of the coal strata is shown by many facts. Along the
)ase of the Cathkin hills, in the glens near Barrhead and Neilston,
ind in natural sections among the Gleniffer hills, the coal strata
aay be seen gradually raised to a high dip, set on end, and finally
eversed when in contact with the trap. The Coast Range of old
ed sandstone from Ardrossan to Port-Glasgow, through which
he Clyde has forced a passage between Bishopton and Dumbuck is
>verlaid throughout by trap rocks. These cover also the eastern
lopes, and come in contact with the coal strata, which are over-
opped by and disappear beneath them. Similar phenomena have
ieen already noticed in describing the Campsie district. The case
igured in the cut of Art. 12 is very interesting. The great stream of
•asaltic matter intruded into the coal strata, encloses a shale bed, c,
fhich has been altered through a considerable distance to the state
f a coarse opal. The sandstone also in the river bed adjoining con-
ains crystals of galena in close proximity to the trap. The changes
* Journal Geolog, Soc., 1852.

36

generally throughout the district are similar to those often described
in connection with the contact of the trap rocks and the sedi-
mentary strata. Some very peculiar effects will be described
farther on.

V.— THE OLD BED SANDSTONE AND ITS LIMESTONES.

27. In addition to what has been already said regarding this rock
as a base to the carboniferous formations, we have now only to
notice those portions of it which appear upon the shores of the frith.
Those on the north are prolongations of the Kilpatrick hills, which,
subsiding at the valley of the Leven, rise again to much lower
altitudes in a ridge bounding the Clyde on the north as far as the
shores of Gareloch. Thence the old red sandstone passes into the
peninsula of Roseneath, in which its junction with the underlying
old slates is strikingly marked on the features of the landscape.*
It crosses nearly through the middle of the remarkable and very
picturesque dell, which intersects the peninsula from Campsail Bay
to Kilcreggan in a direction nearly north-east and south-west.
Thus, in external aspect, and in the nature of its rocks, this southern
portion is isolated from the rest ; it consists of a single hill of a
depressed conical form, having a smooth outline, and extending in
gentle and fertile slopes to the water's edge on three sides. Here,
as in other places, the soil formed by the decomposition of the
sandstone contrasts most favourably with that which rests upon the
cold retentive clays of the coal formation on the one side, and the
old slate rocks on the other. The series exhibits but its lowest
members — conglomerates, coarse sandstone — and finely laminated
red sand, irregularly disposed. The base of the conglomerate is
coarse red sand ; and the imbedded fragments are granite, porphyry
quartz, and various kinds of slate ; the three former are very much
rounded, the latter have lost their angularity, and present elliptic
forms. The origin of these is to be looked for in some near district
of the Grampians, where such varieties exist, and which we know
were elevated and exposed to the action of mechanical forces prior
to the epoch of the old red sandstone ; the quartz and slate pebbles
are from the adjoining strata.

The contact of the sandstone and slate is nowhere seen. In the
western part of the cliffs at Portkill Bay, the two rocks approach

* "Rosencath" is said by some to mean in the Gaelic language, "the little dell, or
dingle ;" and that the name was given to the whole from this peculiar feature. See
Ncic Statistical Account tinder " Roseneath Parish, Dumbartonshire,''

37

very close, the sandstone dipping at a small angle towards the nearly
vertical slate; and in Campsail Bay a considerable space of flat
beach intervenes, concealing the contact. The line of junction
passes near the Saw-mill, and across the upper part of the fields
sloping down from the northern edge of the plantation which crowns
the heights on the south side of the great hollow or dingle.

On the southern coast of Portkill the sandstone dips for a short
distance toward the south ; the dip then changes, and continues in
other parts to be between west and south-west, at an angle of about
15° to 20°. About Tnellan, and thence to Toward Point, the old
red with subordinate beds of limestone occupies the coast, occurring
in small patches over the slate, extending, however, no farther
inland than the well marked terrace which exists here, whose front
shows the slate rock from base to summit. But neither in the
sandstone nor limestone have fossils yet been found. Similar
limestone bands occur in the old red on the opposite coast at
Innerkip ; and at the south base of Benlomond they descend to the
very bottom beds of the old red, not far from the mica slate. In
none of these localities have we ever found any fossils save a few
crushed bivalves. The English cornstones (Momnouth and Pem-
broke) have yielded some ichthy elites (ceplwlaspis) . The most
considerable body of cornstone in the West of Scotland is at Kil-
chattan, in Bute, to which reference will again be made,

28. The coast section of Renfrewshire presents only old red sand-
stone and trap with occasional beds of limestone. The sandstone
rises seaward, dipping east and south-east, at a small angle, and
everywhere occupies the coast except at Kempoch Point and
Cloch Point, where the overlying trap reaches the coast line, and is
seen between high and low water, resting upon and altering the
sandstone. The great overlying mass of trap sends out innumerable
dikes intersecting the sandstone of the coast, and running in very
various directions, but with a general tendency to the west and
north-west. Into a minute description of these, and the changes
produced by them upon the rocks which they intersect, we cannot
enter in this place. One instance only will be given, as bearing
upon the changes induced on limestone. This rock appears in two
places near Innerkip ; one bed extends from the bridge on the
Greenock road, at the north end of the village, up into the hill on
the south-east of the village, rising with the slope of the sandstone
beds, and preserving a thickness throughout, of about twelve feet ;
it has been extensively quarried behind -the village, but is now little
worked. As it is extremely hard, and contains much chert dis-

38

seminated in veins and bands, the rock is capable of taking a fine
polish, and of being applied to ornamental purposes ; — the colour is
dark gray. Between the limestone and the sandstone above it,
there is interposed a bed of loose materials, consisting of red sand,
marked with round gray spots, and enclosing pieces of limestone and
sandstone. Hence the bed of lime must have been exposed to
considerable decomposition before the sandstone was deposited over
it. A lengthened and careful search was not rewarded by the dis-
covery of any fossils. It is, however, obviously in the position of the
cornstones of England,

Several beds separated by strata of sandstone occur on the shore
at the mouth of the river. The whole series is here traversed by
dikes of greenstone, the largest of which is about sixty feet wide,
and ranges about N.N.W.; the others are so numerous, and so
ramified, as almost to defy description. They pierce through the
limestone in every direction, thin veins branching from the greater,
and often again uniting, while small portions of the limestone and
sandstone are entangled in the trap, and traverse it in disconnected
veins. The changes produced upon the limestone are of the most
interesting kind ; we know of no locality in the West of Scotland
where the posterior origin and intrusive character of the trap rocks
are so clearly manifested, and would strongly recommend it as a
point to be visited by the student of geology. The changes which
the limestone has undergone run through every variety of external
aspect, from the impure, dark coloured, perfectly opaque state, to
that of a pure white marble, translucent on the edges, homogeneous
throughout, and devoid of stratification, or visible lines of cleavage.
Intermediate between these extremes there are an indurated semi-
crystalline limestone, a granular saccharine marble crumbling into
fine powder under slight pressure, and phosphorescing when thrown
upon a heated surface ; a very hard white or blue crystalline marble,
having the crystals in distinct plates ; the degree of alteration
depending on the distance from the sides of the dike. The
entangled portions are among those which exhibit the greatest
amount of change. The most altered parts of the sandstone re-
semble quartz rock.

In order to determine whether any and what chemical changes
had been induced simultaneously with these alterations of mineral
character, and to afford terms of comparison with metamorphic
action upon other limestones, Dr. Robert Dundas Thomson most
kindly furnished us with analyses of several specimens, made under
his own care. These are as follows : —

39

Specimen No. 1. is the unaltered limestone, as pure a specimen to
the eye as could be selected.

No. 2. is a saccharine marble, crumbling readily into powder.

No. 3. is the most altered specimen in this locality, described
above as "a pure white marble, translucent on the edges," &c., and
which turns out to be table spar.

No. 4. is a carefully picked specimen of the same, free from car-
bonate of lime.

No. 5. is a calcareous sandstone, altered by contact, scarcely
distinguishable from No. 2.

No. 1.

Carbonic acid, 42*40

Lime...... 54'58

Silica, 0-70

Magnesia, 0'40

Water and loss, 1*92

100-00

No. 2.

Carbonic acid, 42-52

Lime, 54-68

Insoluble siliceous matter, 1*14

Magnesia, ...a trace.

98-34
No. 3. — Spec. Grav. 2-88

Silica, 47-50 48-00 46-64 49-38

Lime, ; 44-90 45'40 46-27 44*59

Protox. of ironl K ,A 1-61 -, AA * An

and alumina, } 5'40 2«01 1<44 1>49

Water, 0'80 0-80 0'80 1-60

Magnesia,..., 0'70 0'83.. 1-05

Soda, ....... 0-92 -94

Carbonic acid and ) 4-85 -QK

loss, 5

99-30 99-57 100-00 100-

No. 4.

Silica, 49-380 In atoms this is

Lime, 44*596 Silica, 24-89 1*93

Alumina and protox. of) ^.490 Lime, 12'74 1

iron, ) And the formula is, omitting

Soda, '936 the impurities —

Magnesia, 1-050 CaO,2SiO,

Water, 1-600 or Bisilicate of lime.

99-052

40

No. 5.

Carbonate of liine, 31*94

Insoluble siliceous matter, 68*06

100-00

It appears from these analyses, 1. That the cornstones of Innerkip
are carbonates of lime and not dolomites.

2. That in this locality igneous action has converted a carbonate
of lime into a bisilicate. Now, as it appears from analyses 1 and 2
that there is but a trace of siliceous matter in the limestone, the
origin of the silica must be sought in the igneous rock ; in fact, a
transference of a portion of its silica must have taken place when the
basalt was in a state of fusion. Such transfer, indeed, could readily
take place under the influence of chemical attractions, when the rocks
were in a state of even imperfect fusion. On No. 4, or the table
spar, Dr. E. D. Thomson remarks : —

" It is an interesting fact in connection with this mineral, that it
gives a yellow colour before the blowpipe when moistened with
muriatic acid ; and yields crystals of common salt when treated with
the same acid. It is thus associated with Wollastonite, or soda table
spar, a mineral occurring in the Bishopton tunnel, and in the Kil-
patrick Hills." There is, however, this difference between the two
cases, that in the localities last mentioned the mineral has no direct
connection with limestone, although calcareous spar occurs abun-
dantly ; whereas at Innerkip, it has obviously originated in a change
induced upon common limestone.

VI.— THE OLD SLATES.

29. These rocks are portions of the great bands of sedimentary strata
which traverse Scotland from sea to sea, in a direction parallel to the
principal axis of the Grampians, and to the great Caledonian valley.
They first strike the shores of the Clyde a little to the east of
Kilcreggan pier in Porthill Bay, where the junction with the old
red sandstone is concealed as already mentioned. They deviate very
little from their ordinary type, and it is therefore unnecessary to
enter into any lengthened descriptions. The usual varieties, depend-
ing upon the varying proportions of the constituent minerals, occur
abundantly, but in no definite order, and without much continuity.
Thus the clay slate series exhibits beds of flinty slate often approach-
ing to quartz rock, of highly bituminous slate, and of coarse grained
compact thick bedded slate, mixed up irregularly with the commoner
kinds, such as coarse and fine roofing slates, and a semi-crystalline

41

silky slate, passing into chlorite or talcose schist. All these varieties
are well seen on the road-side between K-oseneath and Kilcreggan,
and on the shore between the latter place and North Ailey. On the
same coast thick cotemporaneous beds and also veins of quartz
occur, in the cavities of which rock-crystal is often met with.
Roofing slate of good quality is obtained from several quarries ; but
neither in this rock nor in the mica slate which underlies it, have
any indications of metallic ores been noticed. Iron pyrites occurs
in the slate rocks in many places. Beds of quartz containing rock-
crystal occur frequently in the mica slate, and are well seen on the
road-side to the west of the village of Gareloch-head. To the east
of Tom-na-hary hill crystals of schorl are found in a variety of mica
slate, containing very little quartz.

30. On a geological map these two slate rocks would be marked as
separated by a definite boundary; but in nature no such distinction
exists ; the transition is in fact so gradual, that it is impossible to
say where the micaceous series terminates, and the argillaceous com-
mences. Towards its outer boundary the mica slate begins to assume
the character of chlorite schist, and to contain occasional beds of fine
roofing slate, the true mica slate still constituting the greater part
of the mass. Farther out, the argillaceous and chlorite slates begin
to prevail, so that the micaceous beds may be said to be subordinate
to them; and thus through oft repeated alternations, we at last
reach the true clay slate series. We can conceive, therefore, of a
certain middle line, along which the strata partake equally of both
characters ; it is this imaginary line which in such a case may fairly
represent the boundary. These remarks are equally applicable to the
other slate rocks of the district, and indeed to all the rocks of this
class in the West of Scotland. In order to explain the mode in which
this gradual loss of a marked character, and assumption of one con-
siderably different was brought about, it is necessary to remember
that the slate beds were originally deposited from the sea, layer over
layer, in a state of silt or fine mud, and afterwards exposed to great
heat, combined with pressure. A slight change in the nature of the
sediment, or in the amount of heat or pressure, would be sufficient
to produce the want of uniformity, and the variations from a definite
type, which we now observe. The arrangement usually is, upper
green or chlorite slate, middle dark coloured clay slate, and inferior
mica slate, in some tracts passing into gneiss, and extending inward
to the Grampian granite. The mica slate has a remarkable structural
arrangement which distinguishes it from the two others ; its crys-
talline laminae are simple foliations, and form only one set of divisional

42

planes ; whereas in the other slates the bedding is traversed by a
second set of planes, those of slaty cleavage, perpendicular to the
bedding or stratification. The general direction of the beds is about
north-east and south-west, the dip being to the south-east, at angles
varying from 40° to 70° ; — but there are many local exceptions.

The great upward movement attendant on the elevation of the
mica slate mass of Benlomond, has thrown the two other slates
several miles southward of the line of bearing which they observe to
the eastward of the mountain ; and in like manner in other tracts
along the Highland frontier, horizontal displacements on a great
scale appear to have affected the two upper slate bands, so that the
middle or dark slate is often seen in direct continuation of the upper
chloritic band, or vice versd. And thus the appearance of frequent
alternation is produced when these bands are traced from point to
point on the line of bearing.

Plutonic and Metamorphic Rocks.

31. The slates above described contain subordinate beds and veins,
which possess considerable interest.

To the right of the summit level of the road between Gareloch-
head and Portincaple Ferry, a remarkable ridge projects from the
smooth outline of the hill side, and trends in a straight line towards
the base of the mountains. It consists of a highly felspathic rock
erupted through the slate. The base is a very compact mixture of
quartz and felspar, in which crystals of felspar and mica are im-
bedded, the latter ingredient being constantly present, the former
often wanting. The prevailing colour is yellowish-red, given by the
felspar in the base. From the prevalence of felspar, and the mode
in which the crystals are disseminated, the rock must be called,
according to the present views, a felspar porphyry ; though the con-
stant presence of mica as a constituent, and the compound character of
the base, seem rather to require that it should be considered a granite.

At the sides of the vein next the slate, the rock is of a more
homogeneous character, resembling a compact claystone or flinty
slate, but still enclosing crystals of mica. The laminae of the slate
in contact with the sides of the vein have a very close resemblance
to this variety: being, in fact, a yellowish-gray fine grained flinty
slate, with occasional spangles of mica. It is thus difficult to de-
termine the exact boundary line between the slate and the vein.
This assimilation of mineral character has obviously been induced by
the coolinjj of the masses from a state of fusion, at nearly the same
rate, but jnore rapidly than the inner portions of the vein. The

43

breadth of the vein is various ; in some places no more than twelve
or fifteen yards, in others as much as twenty-five, and even thirty,
and perhaps considerably more, as it cannot in many places be
exactly measured. It rises above the surface of the hill side from
fifteen to forty feet, and with several undulations runs in a general
N.N.E. and S.S.W. direction.

In the northern part of its course it is interposed as a bed between
the strata of slate. To the south of the high road, on the side of a
little stream, it is seen intersecting the beds at a small angle. A
little farther south the ground rises, and the vein does not appear
upon the surface ; but on the lowering of the ground still farther
south, it again emerges from beneath the slate and occupies the sur-
face for some distance. A similar overlapping occurs farther north,
near the high road.

The appearance of this plutonic rock, now as a bed interposed
among the strata, and again as a vein intersecting them, and the un-
dulating course which it pursues, point out its posterior origin and the
nature of the resisting force. This is plainly to be found in the pecu-
liar undulations and twisted forms which everywhere characterize the
mica slate, indicating the power-
ful compressing forces which
acted upon it while yet plastic
under the influence of heat.

Near the summit of the
ridge, and at a curvature in
the vein, the outer or salient
angle is intersected by a dike
of greenstone and basalt, in
such a manner that a portion
of the felspathic rock is isolated
between the whin dike and the
mica slate on the west side, and
the continuation of the vein lies
on the same side of the dike as
before the intersection. The an-
nexed sketch, which is a ground
plan, shows the mode of this
intersection, one of the most
singular we have ever met with.

The dike is very distinctly
traceable for several hundred yards towards the north-east, the
surface occupied by it rising into conical hummocks. It is then

(a a) Vein of felspathic rock,
(b &) Altered schist.
(c c) Dike of greenstone and oasalt.
(dd) Mica slate.

44

lost in marshy ground for a short distance, but is again continued
towards the mountains. In the other direction, its course was satis-
factorily made out as far as Portincaple Ferry, where it is well seen ;
and a dike of the same width and bearing, which seems to be a pro-
longation of this dike, was met with near the top of the mountain on
the east side of Loch Eck, traversing mica slate and altering it con-
siderably. The width is about twenty-five yards, and it bears a point
S. of W. It is in many places inclined at the same angle as the
slate, among the beds of which it seems to have insinuated itself
in a serpentine course. The mica slate in some places is slightly
changed by the contact, being rendered harder and more massive :
the lamination is partially destroyed, and the rock is banded,
parallel to the sides of the dike. In one place pieces of the slate
are seen enclosed in the dike, and slightly altered. Portions of
the wedge-shaped mass of slate (d), between the two veins, are
entangled in the basaltic dike, and altered in the same manner.
The circumstances of this case clearly show the posterior origin of
the basalt.

At the edges the dike consists of blue slaty basalt, but the greater
part of the mass is a coarse grained greenstone, which at several
points exhibits in great perfection that peculiar structural arrange-
ment in concretionary spheroids, which is the most frequent and
characteristic form assumed by the trap rocks, and of which the
columnar is but the result, when under favourable conditions, they
parted more slowly with their heat of fluidity. The best marked of
these is in a cliff about sixty feet high, overhanging the marshy
ground above mentioned, where the dike has a considerable underlie,
the slate being in contact on both sides. It is here divided into
columns of spheroids perpendicular 'to the sides of the dike, and
separated from one another by imperfect joints. Sometimes each
joint is composed of a single spheroid ; one was noticed measuring
fifteen inches by ten ; in other cases numerous small closely packed
spheroids make up a joint. Instead of a distinct separation as in
basaltic pillars, the columns are connected by narrow seams of de-
composed greenstone. The columnar structure is here seen in the
act of development. If the heat had parted more gradually, a fagade
of pillars would have been the result. This spot affords an excellent
illustration of the remarkable experiments of Mr. Gregory Watt on
fused basalt (Phil Trans., 1804).

It will appear from the foregoing statements, that the small area
we have been describing, is one of considerable interest, exhibiting,
as it does, the rare association of many species of erupted rocks in

45

connection with the primary strata; and affording illustration of
some curious questions in theoretical geology.

Limestone.

32. On the shore of Loch Long, north of Kilcreggan, and
about 250 yards south of the landing pier at Cove, a bed of lime-
stone is interstratified with the clay slate. It has been originally
six or seven yards wide, and has extended eastwards across the low
ground between the shore and the cliff, into the cliff itself, and
probably much farther inland ; but it cannot be satisfactorily traced.
The part next the shore has been almost entirely removed by quarry-
ing ; but from portions which are found among the slate — as shown
in the annexed sketch, which is a vertical section — there can be no
doubt of the true position of the bed.

(a a) Inclined strata of clay slate; (6) Bed of limestone ; (c) Bay with accumulations

of shingle.

The limestone is impure, from intermixture with slaty lamina? ;
the prevailing colour is bluish-gray; it contains much calcareous
spar ; and, like the slate, is destitute of fossils.

In the new statistical account of the parish of Row adjoining, beds
of limestone are stated to occur in the slate rocks of Glenfruin ; these
are most probably similar to the bed now mentioned.

In a paper by Mr. Daniel Sharpe, F.Gr.S.,* many limestone beds
in various tracts which Dr. MacCulloch and other observers have de-
scribed as belonging to the primary strata are referred to the old red
system; and he expresses a decided opinion with regard to all of
them, denying the occurrence of such beds in association with at
least the clay slate system. The cases here given clearly disprove
this view.

Slates of tlie Cowal Coast.

33. This coast consists of slates of the chloritic and agrillaceous
series, passing westwards into mica slate. The slates near Dunoon
are associated with rocks of igneous origin, to whose effect upon the

* Jour. ofGeol Soc., 1852.

46

slates, and their own peculiar forms, much of the picturesque beauty
of this favourite watering-place is due. Thus the ridge lying be-
tween the coast and the valley of Hafton lake, owes its elevation and
bold outline to an outburst of igneous rocks, which have induced a
very decided change upon the slate along the planes of contact. It
consists of crystalline greenstone, of a different type from that of the
dikes common on the coast, the structure being slaty and the horn-
blende in excess. It is from 60 to 100 yards wide, and ranges from
near Hunter's Quay, across the highest part of the ridge, trans-
versely to its length, appearing along the summit in a series of conical
hummocks, with deep hollows between ; and thus presenting a bold
picturesque outline when viewed from the low grounds in the neigh-
bourhood. It is interrupted by the Hafton valley, but is resumed
on its western side, and attains its greatest altitude in Dunloskin
hill, which rises prominently above the surrounding slopes, strikingly
relieving their monotonous outline. Westwards, for about half, a
mile, it is seen in other rocky eminences, but its farther extension
in this direction was not traced. The ridge is not seen intersecting
the coast, which is everywhere occupied by the slate rocks ; so that
it seems to terminate before reaching the shore. Owing to the
metamorphic character which has been impressed upon the adjoining
slaty beds, it is difficult to determine the precise limits of the
plutonic rock ; near the contact the slate breaks under the hammer
into very compact four-sided prisms.

In a similar manner, the high ground dividing the East and West
Bays, and projecting beyond the general line of coast, has acquired
its strikingly picturesque aspect from a great dike of basalt which
traverses it. The castle hill consists of this dike, and of slate borne
up with it, and adhering to it. By contact with the dike, the slaty
structure is effaced ; the rock has been fused and reconsolidated into
a compact flinty slate, closely resembling basalt; crystals are de-
veloped along the boundary, and bands of different colours are dis-
posed parallel to the sides of the dike. The width is about 100 feet,
and the bearing W.N.W. The G-antock rocks are exactly in the
line of bearing, but were found to consist of very hard slate. On
the opposite coast, however, near Ardgowan, a dike of the same
width and direction occurs, which may be the continuation.

Near Inellan the slates are covered by patches of old red sand-
stone and its associated cornstone, as already mentioned.

47

VII.— THE CLYDE ISLANDS.
BUTE.

34. A pretty full and generally accurate account of the geology of
Bute has been given by Dr. MacCulloch in his work on the Western
Isles, published in" 1819. For thirty years after, no observations,
so far as we can learn, were put on record respecting it, except some
notices of its remarkable coast terrace and raised shelly deposits by
Mr. Smith of Jordanhill. The greater variety of the strata in
Arran, and the bearing of the phenomena there exhibited upon
questions in theoretical geology actively discussed at the time, drew
attention entirely to that island, and Bute, in common with other
parts of the West of Scotland, was overlooked. Yet it has many
points of great interest ; strata occur here to be met with nowhere
else in Scotland ; and the effects of its trap dikes upon the adjoining
strata, are without parallel in the history of theoretical geology.
The phenomena to which we allude were not observed by Dr.
MacCulloch ; and were first made known to geologists in two papers,
published in The Transactions of the Glasgow Philosophical Society
for 1848, and The London Philosophical Magazine for August,
1849. We shall first briefly notice the general structure of the
island ; and then describe at greater length the remarkable changes
referred to, and those strata to be seen nowhere else, and therefore
more worthy of the student's attention.

35. Three deep depressions or valleys traverse Bute perpendicularly
to its longer axis, dividing the island into four portions, and marking
the boundaries of as many distinct geological formations. They
terminate on either side in bays or indentations of the land, formed
here as in most other cases at the points of least resistance, the
junctions, namely, of dissimilar strata. Those on the east side are
the well known sheltered bays of Kames, Bothesay, and Kilchattan.
The low tracts in question show no rock in situ, but are filled with
shingle and alluvial deposits concealing the junctions, strata of
peat, and occasional shell beds. The deposit already referred to
(Art. 5), as described by Mr. Miller in The Witness of July, 1855,
lay in the Bothesay valley ; and a similar one with numerous shells
has since been found in the valley at Kames bay. These have not
yielded any additional species to those found by Mr. Smith, and
already given in our list. The elevation above the sea level has been
shown by Mr. Bobert Chambers in his interesting and beautifully
illustrated work on ancient sea margins, nowhere to exceed thirty
feet ; and as this is also very nearly the height of the terrace already

48

referred to as encircling the island, it appears that when the sea
stood at that ancient level, Bute consisted of four islands separated
by narrow channels.

The various strata exhibited in Bute, are the terminal portions
of those great bands of rock, sedimentary and igneous, which
extend across the country from sea to sea, as already noticed. Mica
slate occupies the northern portion between the Kyles on the north,
and Kames and Ettrick bays on the south. The rock has its usual
character and aspect ; and rises into hills of nearly 1,000 feet eleva-
tion. The district south of this, bounded by the Eothesay valley,
consists of the two upper slates, the common clay and chloritic.
Subordinate to these are great beds of quartz rock, the most con-
siderable of which forms the high ridge called Barone hill, with a
picturesque old ruin overlooking Rothesay on the west ; and also in
the vicinity of Kames bay, copper veins very recently discovered
and of considerable promise, arrangements for working which are
now in progress. The portion extending from Eothesay valley to
Kilchattan is occupied by red sandstone ; and finally the southern
portion with a sub-stratum of red sandstone, consists mainly of
various rocks of the trap family, erupted through and overlying the
sandstone. The accompanying outline of the island shows the
relation of these strata to the valleys or depressions, which are
obviously a part of that system of parallel fractures ranging N.E.
and S.W. on both sides of the Grampians, and probably due to the
upheaval of this chain, and the later igneous eruptions already
noted.

(a) Kames bay ; (6) RotJiesay ; (c) Kilchattan ; (m) mica slate ; (n) clay and chlorite
slates; (s) red sandstone ; (f)trap; (r) the terrace.

A description of these rocks would be useless, as it would
merely be a repetition of facts contained in all elementary works.
The great body of sandstone obviously belongs to the old red
system ; and as well from its position in immediate sequence to the
old strata, as from its general mineral character seems to form
the lower portion of that system; but hitherto no fossils have
been detected in it. Like the corresponding strata on the mainland,
at the base of Benlomond, Innerkip and Inellan, it contains sub-
ordinate beds of cornstone. These are seen in several places along
the shore south of Bogany point ; but the beds are thin, and
generally contain much siliceous matter, so that the limestone is of

49

no economical value. The Kilchattan beds are of the same age ;
they are subordinate to sandstone and without fossils, but being of
considerable thickness, they have been extensively quarried.

36. But there are in Bute sandstones and limestones newer
than these, which have been till very recently quite overlooked
by geologists. There occurs, in fact, hanging on to the flanks of
the old red sandstone at Ascog, a small coal formation, a portion of
the lower marine series. This was lately discovered and identified
by means of its fossils, about the same time, and independently of
one another, by Mr. James Frazer of Glasgow and the writer of
these notices, and may yet turn out to be of economic value. It is
connected with an isolated overlying mass of trap appearing on the
shore, and occupying the cliffs near Ascog mill. On the north side
of the promontory, south of the mill, several thin courses of nodular
limestone traverse beds of brown coloured crumbling shale subordi-
nate to sandstone. The shale is of considerable thickness and rises
into banks above the road. The south side of the promontory pre-
sents the following section : —

(a) Limestone; (6) shale with thin coal seams; (c) limestone breccia; (d) trap.

The lowest bed (a) is a fine grained, bluish-gray, nodular lime-
stone. Over it is a bed of black bituminous shale (b), containing
veins of coal about a quarter of an inch thick ; and upon these rests
a bed of concretionary limestone (c), the base or paste being a dark
coloured limestone, and the concretions rounded lumps of the same
rock, often of considerable size. The upper part of the cliff is
occupied by trap in various prismatic forms. The base of the con-
cretionary limestone is so much altered by the contact of the trap,
that the two rocks can only be distinguished by the action of a
strong acid. A like change is produced upon the imbedded lumps

50

in the upper part of the hed. The limestone, shale, and coal seams
extend under high-water mark, and when the tide is very low con-
siderable pieces of coal are often dug out from beneath the sand
and mud covering the tide-way. Several sinkings have been made
here for the purpose of discovering workable coal seams, but without
success. The fossils by which the strata were identified as belonging
to the carboniferous system are given in the following list. The
species have been determined by Mr. Frazer, from specimens in his
collection and our own : —

Plantae.
Sphenopteris bifida, not uncommon in the shales.

affinis, ditto,

furcata, ditto,

dilatata (rare).

Pecopteris nervosa (rare).

Calamites nodosus, abundant in the sandstone and shale,

undulatus. ditto.

Trigonocarpmn olivaeforme (rare).

Brachiopoda.

Producta punctata, not abundant.

• sulcata, ditto.

Spirifer semicircularis, somewhat common.

trigonalis (rare).

Spirifer duplicostata (rare).

Lingula squamiformis, abundant in the shales.

Orthis radialis (rare).

37. The trap above referred to as overlying these strata is a pro-
jection or tongue, running down to the shore from the principal
mass above, which occupies a considerable area inland towards
Ascog lake, and is upwards of 100 feet thick. It is seen in the
summit of the cliffs on either side, the line of junction ascending
rapidly as it retires from the shore. These trap rocks at Ascog
derive their chief interest from being the repository of beds of lignite ;
a substance so rare in Scotland, that no well-marked beds occur on
the mainland, and but few in the other islands ; and these in
situations very difficult of access. A careful examination of this car-
bonaceous deposit was suggested by the statement of Dr. MacCulloch,
that some of the beds occurring here were unlike any he had seen in
his survey of the Western Islands.

The principal bed is situated in the face of the cliffs above the road,

51

a little to the south of Ascog mill, as shown in the annexed section
giving the various beds : —

(s) Sandstone; (f) terrace and road; (jf) greenstone; (a) trap-tuff; (5) red ochre;
(c) lignite bed; (c?) pisolitic ochre; (e) porphyritic amygdaloid, the upper portion
much altered.

The lowest bed resting on the sandstone is a small-grained rudely
columnar greenstone ; the junction is, however, concealed. Over
this is a trap-tuff with a base of greenstone, and imbedded spherical
lumps of the same substance. This is followed by a bed of red ochre
of coarse texture, traversed by numerous black iron-seams, which
have doubtless been produced from a change in the oxidation of the
component iron. Over this is the lignite bed : it is three feet thick,
and consists of hard stony coal, interstratified with a yellowish-white
shale, both being much intermixed with pyrites. The coal has been
so much altered throughout its whole thickness by the contact of the
trap rock, that Mr. Rose of Edinburgh, to whose examination the
best specimens that could be selected were submitted, in order
that he might determine the species of wood, but without any note
of the geological situation of the coal, was " unable to obtain a slice
in consequence of the structure being altered by the contact of a whin
dike." The coal has been worked to some extent by driving an
adit inwards on the line of the dip, which is about 20° to the
westward ; but the workings have been for some time abandoned,
and the inner and lower portions are now full of water.

The floor of the coal has been already described. The roof is a
peculiar rock. It consists of a base or paste of an ochreous steatite,
with imbedded round pieces of the same substance, and may hence
be called a pisolitic ochre ; it is three and a-half yards thick. The
bed above this 'Lis of the same character ; but the base feels less
unctuous, and with the imbedded steatite it contains also imbedded
calcareous spar. The base effervesces briskly with an acid; and

52

hence we may call the rock a calcareous amygdaloid. The upper
portion of this bed, to the thickness of a few inches only, is very
hard, and has a semivitreous appearance, and thus closely resembles
a porphyry. In common with the trap above, and, indeed, all the
beds in this locality, it contains much disseminated iron. The rest
of the cliff is occupied by greenstone, similar to the lower bed in
contact with the sandstone.

Another bed of lignite occurs on the opposite, or north-west side
of the trap district, overlooking Ascog lake. The coal dips to the
interior of the area, that is, nearly south. It is of about the same
thickness, and is accompanied by beds of steatite and red ochre, very
similar to those above described ; but the nature of the ground is
such that a complete section cannot be had, and the precise number,
therefore, and order of the beds cannot be exactly stated. The
association, however of the lignite with ochres and steatites here also
is sufficiently distinct, and it is even probable that these beds are
persistent throughout the whole of this district. It is to these
ochreous and steatitic beds that Dr. MacCulloch refers when he says
that he "has met with no similar substance among the numerous
trap rocks examined in the course of the survey of the Western
Islands." He has not indeed described any such strata ; yet casual
mention is made (vol. i., p. 376) of an iron clay and jaspery substance,
forming extensive beds in the trap of the cliffs of Talisker in Skye
— the same in which the lignite also occurs — and that these are
often variegated with red, gray, and purple colours. No further
description is given, nor is the precise position of the lignite men-
tioned, ttie cliffs being of very difficult access.

But even by such a brief notice the steatitic beds and variegated
ochres are easily recognized; and though these characters are not
very distinctly marked in the beds we have been describing in Bute,
yet they apply exactly to the red and variegated ochres, which
occur as members of the trap series of the north-east of Ireland.
The trap rocks there cover an area of upwards of 1,000 square miles,
and vary in thickness from 300 to 1,200 feet. They repose upon
chalk, while the Scottish series rests on the old red sandstone and
coal strata. In the Irish series the lignites occur in the middle
and upper parts, associated with variegated ochre and basalt. There
is, as we have seen, a like association in Bute. The interesting
leaf-beds and associated lignites, overlaid by trap in Mull, discovered
and described by the Duke of Argyle (Jour. Geol. Soc., 1851),
seem to be a deposit precisely analogous to the Antrim and Bute
lignites ; and from the casual observations of Dr. MacCulloch it

53

would appear that such beds occur also in Skye and others of the
Western Isles. Similar conditions thus appear to have prevailed over
a very wide area, the successive eruptions of igneous matter over the
sea bottom were very similar, and there were like periods of repose,
during which the productions of the adjoining land were swept
down to be buried under the next flow of submarine lava.

The wood which has supplied the Antrim and Mull lignites, has
been ascertained to be coniferous ; but the species have not been
determined. Mr. Eobert Brown and Professor Lindley referred the
former with some hesitation to one of two species — the common fir
(Pinus Abies) or the Weymouth pine (P. Strobus); and Professor
Edward Forbes, who reported upon the Mull leaves, at the request
of the Duke of Argyle, found that they belonged to a taxus, a
platanus, and several species of rhamnites, upon which he did not
venture to pronounce positively (Jour. Geol. Soc., vol. vii., p. 103,
1851). The lignites which occur in Mull in a bed under basalt,
apparently in direct continuation of the leaf-beds, have been
recently submitted by Professors Harkness and Blyth to a micro-
scopical and chemical examination, and their structure compared
with that of the Causeway lignites (Ed. Phil. Jour., New Ser., iv.,
p. 304, 1856). The results show that the variations from the ordinary
coniferous structure are the effects of the great pressure to which
they were subjected by the accumulation over them of thick beds
of igneous matter. We have failed, as already remarked, in deter-
mining the nature of the Bute lignite ; but it has quite the appear-
ance of being coniferous ; and the beds associated with it being
exactly the same as accompany the Antrim lignites, there is every
probability that both are of the same age. Now, the basaltic series
of the north-east of Ireland, as it overlies the chalk formation,
clearly belongs to the tertiary era, and was long ago recognized as
of this age. But many cases occur in which the same basaltic flow,
which alters the chalk to the state of a saccharine marble, spreads
out beyond the limits of the chalk, and overlies and alters the
new red sandstone and coal measures. Such overlying masses must
also belong to the tertiary period. It is therefore not improbable
that the basalts forming the lofty cliffs on the west coast of Mull,
superimposed upon the lias and oolites, may also be tertiary. The
Duke of Argyle is inclined to refer these to an older date ; while
his Grace, in the able and interesting paper above mentioned, clearly
shows that the Ardtun leaf-beds and lignites are of tertiary age. It
seems to us, however, to be premature to place these and the Antrim
lignites in the miocene group, as his Grace and Sir Charles Lyell

54

have done, until greater certainty is attained with regard to the
species to which the leaves and lignites are to be referred. — It is not
then improbable, that our Bute trap formation, with its ochres and
lignites, may also be of tertiary age, though overlying the older
secondary strata.

The chemical composition of ochre is almost exactly the same
as that of basalt ; 100 parts consist of — silex 56'40, alumina 3'46,
per-ox. iron 24'14, carb. lime 0'90, water 15 '10. It is in fact a
decomposed basalt, partially refused and reconsolidated by the suc-
ceeding flow of igenous matter.

38. The Kilchattan limestone already referred to is the most
considerable mass on the island. It is a cornstone subordinate to
the old red sandstone ; the strata of the two rocks are conformable,
and the dip nearly south at a moderate angle. At the summit of the
ridge near the picturesque ruins of the ancient castle of Kelspoke
the sandstone over the limestone is seen dipping under the trap
which bounds the rugged terraced ridges descending towards Garroch-
head on the south coast. These ridges have the same inclination
southwards as the underlying sandstone strata, and present a sue.
cession of bold fronts towards the north. The sandstone appears to
have had its present inclination when the submarine lava streams,
of which these ridges consist, were poured out over it ; the scarped
fronts were no doubt formed by the action of currents when the
land was rising. The arrangement of the strata at Kilchattan is
shown in the annexed cut.* No fossils were found in the limestone.

(a, 6) Sandstone; (c) limestone; (d) trap.

39. The dikes of Bute are composed of greenstone, or basalt, and
are very numerous, especially on the east coast. They traverse the
strata in various directions, and in some cases can be traced for several
miles continuously, preserving nearly the same width and direction
throughout, t Two or more are sometimes seen to meet and coalesce

* This and the other cuts illustrative of Bute are copied, by permission, from the
Journal of the Glasgow Philosophical Society for 1848.

f A dike seventy feet wide emerges from the sea at the mineral well near Bogany point,
and ranging nearly west is seen in Huntly Place, where it has been largely quarried ;
interrupted by the bay it rises again, is conspicuous across the high grounds west of the
town, and crossing the island, enters the sea at Ettrick bay. Here another dike, two

55

for some distance, and again to separate ; — a narrow dike branches
off into several filaments, which unite again — portions of the rock
traversed are often found entangled in the dike ; and these, as well
as the contiguous strata, present the usual metamorphic effects
recognized as due to igneous action, besides others of a peculiar
and exceptional character, to which we shall now allude.

The Kilchattan limestone is altered in a remarkable manner by
a large dike, crossing it nearly in the direction of the dip, and
the effects are well seen at the eastern side of the quarry. Along
the plane of contact with the dike the limestone is altered to the
state of a granular saccharine marble, which on the application of a
slight pressure crumbles into a fine powder. This is succeeded by a
hard crystalline marble, the crystals appearing in distinct flakes.
Between this and the first change, which is one of simple induration,
there are many gradations. Similar effects are common at the
contact of limestone with plutonic rocks ; in some localities they are
accompanied by other singular changes of a chemical nature. Mag-
nesia, and sometimes silica and alumina, are introduced into the
composition of the limestone, so that simple carbonate of lime
becomes a double carbonate of lime and magnesia. The source
whence this magnesia has been derived has occasioned much dif-
ference of opinion among geologists. Some imagine that it has
been transferred from the plutonic rock to the limestone ; while
others hold that, as fractures and dislocations of the earth's crust
accompanied the eruption of these plutonic rocks, gaseous exhala-
tions might find their way from beneath, and introduce carbonate
of magnesia and other substances into rocks near the surface. In
confirmation of this view Mr. Phillips has shown, in his Geology of
Yorkshire, that " common limestone is dolomitized by the sides of
faults and mineral veins far away from igneous rocks of any kind ;"
and some distinguished chemists have expressed their belief that
carbonate of magnesia may be sublimed by the action of great heat.
(Rep. Brit. Assoc. for 1835, Trans. Sect., p. 51 ; Phillips's Geology,

or three times the width, enters near it, crossing from Ascog, and visible in several
eminences in the interior. The Eothesay mineral water, which has acquired some repu-
tation for efficacy in rheumatic, cutaneous, and glandular complaints, rises in the former
of these two dikes, at Bogany point. The gallon'of 277-274 cub. inches contains, accord-
ing to the analysis of Dr. Thomson, — com. salt, 1860'73 grains; sulph. lime, 125-20;
sulph. soda, 129-77; mur. magnesia, 32-80; silica, 14-39; sulphuretted hydrogen, 17-4
cub. inches. Both dikes and this mineral water are noticed at some length in Wilson's
Guide to Rothesay and the Island of Bute, an excellent and neatly illustrated little
work, full of interesting historical and antiquarian matter, but unfortunately, extremely
meagre on the geology.

56

in Cab. Cyclop., vol. ii., p. 98). Much doubt, however, still hangs
about this subject. Cases occur in which magnesia has been intro-
duced, although the limestone could not have been subject to such
a pressure as would confine its carbonic acid when the rock was
softened by heat.

In order to elucidate, if possible, this obscure subject, two speci-
mens of the rock were submitted to Mr. John Macadam, lecturer
on chemistry, now of the Melbourne Philosophical Institution, for
examination with reference to the presence or absence of magnesia.
The following is Mr. Macadam's report ; the specimen referred to
as No. 1 is the saccharine marble from contact with the dike ; No. 2
is the unaltered limestone — both were average specimens : —

" I have carefully subjected to chemical analysis the specimen of
limestone No. 1, with special reference to the presence or absence
of magnesia ; and I find from the indications given that carbonate
of magnesia constitutes about 2^ per cent, of the whole mass. The
mineral is not, therefore, a double carbonate of lime and magnesia.
Its other and principal ingredients are carbonic acid and lime,
besides which silica is present, as also traces of oxide of iron and
alumina.

" In the specimen No. 2, I find magnesia in great abundance, the
amount present being equivalent to 33*72 per cent, of carbonate of
magnesia. The other constituents present are similar to those
reported in No. 1. From the large proportions of carbonate of lime
and carbonate of magnesia present in specimen No. 2, it would
appear to be a species of dolomite. It may be noticed that the
physical characters of No. 2 are very different from those of No. 1 ;
the former is difficult to pulverize, the latter is extremely susceptible
of division.

" The action of strong hydrochloric acid on both specimens causes
a portion of gelatinous silica to appear, showing the presence of a
silicate, which may be that of magnesia, since the quantity of gelati-
nous silica is about sufficient to combine with the 1*28 per cent, of
caustic magnesia existing in the specimen No. 1. There is a less
quantity of this gelatinous sih'ca in No. 2. The greater portion,
however, of the silica present in both specimens remains undissolved
in the gritty or pulverulent condition, and is hence in a state of
mere mechanical mixture with the other constituents of the lime-
stone. It would require a minute quantitative analysis to determine
whether the T28 per cent, of magnesia exists as a carbonate or
silicate, or partly as both."

The phenomena are thus of a contrary character to what is usually

57

found ; the unaltered rock is a dolomite, and contains nearly 34 per
cent, of carbonate of magnesia, while the altered rock contains less
than 3 per cent. What has become of the constituent magnesia ?
Has it been driven off by the heat to which the limestone was
exposed ? Most chemists are unwilling to admit that this is pos-
sible ; and it may reasonably be objected, that if the limestone had
been exposed to so high a temperature as to vaporize its magnesia,
the silica would not be mechanically present, but would have entered
into chemical combination with the lime or the magnesia, and have
formed a silicate.

That whin dikes have sometimes been the means of producing
such a combination has been shown by an eminent chemist. In a
valuable paper by Dr. Apjohn on the Dolomites of Ireland, published
in the Dublin Geological Journal, vol. i., the details of an analysis
of the white chalk of Antrim, altered to the state of a saccharine
marble, are given (p. 376) ; and it is remarked in conclusion, that
" the stone under consideration consists of silica, combined with the
mixed oxides of calcium, magnesium, and iron (the carbonate of lime
being mechanically present), and is therefore a mixture of trisilicates,
very analogous in its composition to olivine. We are thus enabled
to understand why olivine should be so very frequently found in
trap rocks, and to refer its origin to the contact of silex at a high
temperature with an excess of the basic oxides ; and we have in some
degree a demonstration that the dolomites which contain siliceous
sand could not have been exposed at any time to a heat sufficiently
high to account for the introduction into them of magnesia in the
vaporous state ; for by such a heat a silicate of lime or magnesia, or
of both, would have been produced."

The presence of these silicates in both our specimens is shown by
the appearance of the gelatinous silica ; yet a greater quantity of
silica is present mechanically, which, as already stated, seems incon-
sistent with the exposure of the rock to intense heat ; unless, indeed,
we could suppose that the silica has been introduced by infiltration,
or the magnesia removed by the solvent power of free carbonic acid
at a period subsequent to the consolidation of the dike from a state
of igneous fusion.

Careful quantitative analyses of the limestones were afterwards
obtained through the kindness of Dr. Eobert D. Thomson. It ia
hoped that these will afford definite terms of comparison with other
analyses, such as those of Dr. Apjohn already referred to ; and that
their publication may lead to the formation of clearer views respect-
ing an obscure question in theoretical geology.

58

The analyses kindly furnished by Dr. Robert D. Thomson are as
follows : —

Specimen No. 1 is the saccharine marble from contact with the
dike at Kilchattan, — in the highest state of alteration.

No. 2 is the hard crystalline marble, having the crystals in distinct
flakes, more remote and less altered than No. 1.

No. 3 is the unaltered limestone from the middle of the quarry,
remote from the dike, — an average specimen.

No. 4 is the altered limestone from contact with the overlying
trap at Ascog Mill ; it is an impure dark coloured rock of an earthy
aspect, and very like the trap which rests upon it.

No. 1. — Spec. grav. 2*710.

"

Protoxide of iron, ............... 1-68 1-50 1-28

Carbonate of lime,.... ......... 90'65 ... 91-08

Carbonate of magnesia, ........ 1*00 ... 1*17

100-24 99-23

No. 2.— Spec. grav. 2-570.

I. II.

: ........................... I 1-94 0-28 0-28

Alumina, ....................... )

Protoxide of iron, ............... 0'52 ... 0'56

Carbonate of lime, .............. 96-48 98'76 96-58

Carbonate of magnesia, ........ 1*23 ... 2 '24

100-17 99-66

No. 3.— Spec. grav. 2-679.

I. II.

I 9-70 9-08

Alumina, ....................... >

Protoxide of iron...... .......... 1-12 ... 1-12

Carbonate of lime, .............. 67'42 72-12 67'00

Carbonate of magnesia, ........ 17'31 ... 18-06

Water, coaly matter, and) ... A-4

i • * i /"TtrtO ••• T. / *±

carbonic acid, .............. )

100-00 100-00

No. 4.

I 64.21 64.46

)

Alumina,

Protoxide of iron, ............... 6-42 6'60

Carbonate of lime, .............. 24-00 21-20

Carbonate of magnesia, ........ 4-62 2'85

"Water and carbonic acid, ..... 1*75 4"89

100-00 100-00
The silica present is in a state of mechanical mixture.

59

These analyses are confirmatory of the main points of the views
already stated, and seem clearly to establish the new and remarkable
fact, that by the igneous action in these instances the magnesia
has been driven off from the limestone. The unaltered rock is a
dolomite containing nearly 70 per cent, of carbonate of lime, and
nearly 20 per cent, of carbonate of magnesia ; while the altered rock
contains but from 1 to 2 per cent, of the latter ingredient. To
what cause are we to assign the changes that have taken place?
Has the magnesia been sublimed by heat ? or has it been withdrawn
by the solvent power of free carbonic acid ? On the nature of these
and the other chemical changes that have been induced, it is diffi-
cult to express an opinion ; and from such limited premises it would
be unphilosophical to draw any general conclusions. The subject is
one, however, of great interest both to the geologist and chemist,
as the facts are directly opposed to the received views ; * and as no
instance of similar changes on dolomitic rocks has, so far as we are
aware, ever been put on record.

40. A remarkable dike intersects the sandstone between Ascog
and Kerrycroy, well worthy of attention on account of the striking
illustration it affords of the mode of cooling of basaltic rocks from
igneous fusion. It runs parallel to the shore for some distance, and
then retires from it towards the S.W., and striking the inland cliff

Side view of whin dike between Ascog and Kerry eroy.

already mentioned, whose direction is here the same as that of the
dike, it forms the perpendicular face of the cliff in front of the sand-
stone, rising like a wall to a height of twenty or thirty feet. The direc-

* For the latest and best account of the views of geologists on this subject see the
well known work of Dr. Daubeny on Volcanoes, new edit. ; also an admirable resume in
the anniversary address of Prof. Oldham in the Journal of the Dublin Geological Society r,
1R19.

60

tion of the cliff soon changes, however, and the dike then enters the hill
behind, and is lost. The sandstone having been completely worn away
from the eastern or seaward face of the dike by the action of the sea,
when it covered the present terrace, a very large surface of the side of
the dike is laid bare, and thus the structure is exhibited in the most
satisfactory manner, as shown in the annexed cut representing the
dike as seen on the east side.

These dikes, as already remarked, are prismatic across, not vertically
as in the overlying trap. The cause has been alluded to in a former
article (Article 31); the imprisoned caloric of the submarine lava-
stream passed off perpendicularly to the cooling surfaces, and hence
the divisional planes are also perpendicular to these surfaces, or the
dike is prismatic across. In this case the prisms are mostly penta-
gons and hexagons. The dike is composed of greenstone, and is about
fifteen feet wide.

THE CUMBKAYS.

41. These islands are composed of old red sandstone similar to
that of the mainland adjoining, broken through and overlaid by
various traps, chiefly greenstone. The cliffs at the lighthouse on
the lesser Cumbray are composed of sheets of prismatic greenstone
rising above one another in successive terraces, having a dip N.E. or
contrary to that of the sandstone and trap of Garroch head, and
hence suggesting the existence here of a great fault in the strata,
giving origin to this main entrance into the proper estuary of the
Clyde. The chief interest of the islands is in their whin dikes. These
alter the strata remarkably: the sandstone has been fused by them,
and reconsolidated into a substance closely resembling a dark quartz
rock ; simple induration is induced at a greater distance from the dike.
Many of the dikes also stand out boldly from the adjoining sand-
stone, which has been worn away on either side as in the case men-
tioned in the last article, the amount of wearing in the ancient
tideway, compared with that in the present, affording a rude measure
of the time during which the sea remained at the higher level.
Attention was first called to these remarkable dikes by Mr. Smith of
Jordanhill. The best example is seen a little to the east of the
entrance of Millport harbour, where a large dike rising from the sea
level like a huge wall runs far up along the hillside, raised as if by
art above the surface of the fields. On the shore of the mainland
opposite, another dike, having the same direction and apparently a
prolongation of this, stands out in the same manner from the surface
of the sandstone. The similarity of the two masses of rock and their

61

former connection are pointed at in the legend that this strait was
once spanned by an enormous bridge, raised by the hand of mighty
wizards, of which the only portions that remain are these two
ancient abutments.*

ARRAN.

42. The Island of Arran is about twenty miles long from N.N.W.
to S.S.E. ; about ten miles broad, and, with Holy Isle and Pladda,
includes an area of about .100,000 acres. The number of rock forma-
tions, sedimentarv and plutonic, which are found within this limited
space, is truly remarkable ; perhaps unparalleled in any tract of like
extent on the surface of the globe ; while the varied phenomena
which they present in their mutual contacts and general relations to
one another, are of the highest import in theoretical geology. The
variety indeed is so great, and the interest so lively and pleasing,
which an examination of the structure of the island and its charming
scenery excite, that, as Professor Phillips has remarked, every geo-
logist who visits Arran is tempted to write about it, and finds some-
thing to add to what has been already put on record. For the
student there cannot be a finer field ; the primary azoic rocks, the
metamorphic slates, the lower palaeozoic strata, the newer erupted
rocks, and phenomena of glacial action, may all be examined by him
in easy excursions of a few days ; and the exposition of the strata is
so complete in the rugged mountains, deep, precipitous glens and
unbroken sea coast sections, that the island may truly be called a
grand museum arranged for his instruction by the hand of nature.

Physical Features. •

43. A line running from the north angle of Brodick bay almost
due west to lorsa waterfoot, divides the island into two nearly equal
portions, strikingly different in their geological structure and in
their outward features. The northern half consists of a mass of
peaked and rugged mountains, intersected by deep and wild glens,
which diverge from a common centre arid open seaward on a narrow
belt of low land. This belt forms the terrace so often noticed
already as marking the ancient sea level, and is bounded inland
by cliffs pierced with caves and otherwise sea-worn. The road is
carried along it from Brodick bay to the mouth of North Sannox
water, and again from Loch Ranza to Dugarry at the mouth of lorsa
water, and affords throughout views of surpassing beauty. The
mountains are naturally divided into three separate ridges, which

* Quart. Jour. ofAgric. and Trans, of (he Hlghl Soc., No. 43, or vol. ix., p. 430.

62

may be named after their most conspicuous summits — the Cior-Mhor,
Goatfell, and Ben-Varen groups. Of these by far the most con-
siderable is the first, which forms a long irregular, narrow, and
jagged ridge, extending from Ben-Ghnuis on the south to Suithi-
Fergus on the north-east. Cior-Mhor stands near its centre at a
point where 'a salient angle in the ridge closely approaches to the
Goatfell group on the east. Its connection to this group by a
cross ridge or col about 1,000 feet in height, which separates the
heads of Glen Rosa and Glen Sannox, and its position near the middle
of the range, constitute the prominent peak of Cior-Mhor, the geo-
graphical centre of the whole north-eastern mass of mountains. Its
height is about 2,500 feet ; but it is exceeded by Caistael-Abhael,
and perhaps another summit. The whole ridge has great persistent
altitude, no point descending below 1,600 feet, and there being at
least six summits not less than 2,000 feet. Fronting the concavity
of this arch-like ridge on the east, is an assemblage of closely con-
nected mountains dependent upon Goatfell. The most northerly
summit is the lofty conical peak of Ciod-na-Oich, or the Maiden's
Breast, guarding the south-east angle of Glen Sannox ; on the south
the group terminates in the bold precipice called Glen Shant rock at
the entrance of Glen Rosa. Both groups front the interior glens in
tremendous precipices, while they descend with less abruptness to
Glen lorsa on one side, and the sea on the other. To the west of
the geographical axis of the island lies the Ben-Varen range, with
some connected and lower heights east of it, the entire group being
separated from the other mountains by Glen lorsa and Glen Eais-
na-Vearraid, running respectively S.S.W. and N.N.W. through the
length of this half of the island. These glens have a common
watershed in Loch -an-Dea vie, a small mountain lake or tarn, which
when it stands at a high level, as in winter and in wet summers,
discharges its waters at both ends. Another small lake adjoining,
at a higher level, likewise discharges, when full of water, north-west
into the head of Glen Catacol and south-east into Glen lorsa ; but
it is a mistake to suppose that Loch Tanna, the largest lake in the
island, has this singular position ; the ground rises suddenly north of
it, and all the water passes off into the lorsa. These Arran lakes
illustrate an arrangement which occurs on a large scale in Canada and
Norway, where lakes extend across the entire watershed between two
seas.

The bleak uplands between Ben-Ghnuis and Ben-Varen are finely
varied by several heights, of which the most remarkable is the
prominent ridge of Sal-Halmidel, an outlier of the latter range. It

63

divides Glen lorsa from Glen Scaftigill, and is a conspicuous and
picturesque object from all the south-western portions of the island.
To complete our sketch of the northern section, it is only necessary
to notice the high ridge between the sea on the north, and north
Glen Sannox and Glen Chalmidel on the south. In geological for-
mation it differs from the others, but is connected with the main
range which we have called the Cior-Mhor group, by means of a
ridge at the watershed between the two glens which bound it. This
ridge joins on to the eastern flanks of Tornidneon, an abrupt, massive,
but not lofty mountain, overlooking Loch Ranza on the south, and
forming the termination of a long but not generally high ridge which
sweeps round the east side of Glen Eais-na-Vearraid, and runs in
upon the north side of Caistael-Abhael near the watershed at Loch-
an-Deavie. This northern range terminates in bold heights forming
the east side of Loch Ranza; its western boundary is formed by the
nearly precipitous sides of Meal-Mhor, the most northerly mountain
of the Ben-Varen group. Thus at the northern apex of the island,
the principal ranges closely approach one another, their terminal
portions forming the lofty abrupt framework to the secluded inlet of
Loch Ranza, whose many picturesque features excite the admiration
of every visitor.

Various estimates have been formed from time to time of the
heights of the Arran mountains ; all of them, including some of our
own made by trigonometrical measurement, pretty near the truth.
They have lately been determined, in the conduct of the Ordnance
Survey, with that exactness which marks all the operations of the
Royal Engineers. The following principal heights have been kindly
supplied by the Superintendent of the Survey, Colonel James, R.E. :
— Goatfell, 2,875 feet ; Caistael-Abhael, 2,801 ; north top of Goat-
fell, 2,628 ; Ben-Varen, south summit, 2,342 ; north summit, 2,310 ;
Holy Isle, 1,020 ; highest point of the slate ridge on the north,
over the Cock of Arran, 1,097 feet.

The southern half of the island consists of a rolling table land,
bleak and unpicturesque inland, but breaking rapidly down seaward
into a coast border of great romantic beauty. The general elevation
is from 500 to 800 feet ; and the irregular ridges which traverse it,
most usually in a direction nearly east and west, rise to about 1,100
or 1,400 feet. These separate the various glens and river-courses,
whose origins lie near the central line or axis of the island, but
often interlace with one another, so that a stream issuing westward
has its source nearer the east coast than the west, and vice versd.
The views of the northern mountains, from these uplands, are

64

very grand, especially when they are seen in the early summer
twilight, their dark jagged peaks projected against a background of
sky, still lit up with brilliant hues from the departed sun. Their
aspect from one such point of view has been given with noble effect
by a living artist. The terrace border, so conspicuous around the
estuary of the Clyde, is marked here with less continuity, owing to
the nature of the rocks which advance in many parts upon the sea
line in mural precipices. Still, however, it is sufficiently distinct in
many parts, as about Corriegills, Whiting bay, portions of the south
End, and towards King's Cove on the west, where its salient and
re-entrant angles, in their bold points and noble sweeps, afford some
of the finest scenes of quiet beauty to be met with in Scotland.

General Outline of the Structure.

44. The remarkable geological structure of Arran, and the strik-
ing physical features which give such a charm to its scenery, are
alike due to a single peculiarity generally overlooked by those who
undertake to describe it. This consists in the abnormal position of
its granite nucleus. The other granite tracts of the north-west of
Scotland lie amid primary slates, which are symmetrically disposed
on opposite sides of it, the granite ridge forming an anticlinal axis.
This is the case throughout the Grampians, where gneiss and mica
slate widely encircle the various outbursts of the granitic rocks ; the
silurian slates of the south of Scotland envelop in the same manner
the granitic bosses which rise amid them. But in Arran there is no
such symmetrical arrangement ; granite does not form a mineral axis
in reference to the slate rocks. It has been protruded close to the outer
border of the two upper slates, so as to come into contact on one
side with the newer sedimentary strata. Its position is thus very
different from that of the Grampian granite, being far removed from
the axis of the old crystalline slates, and associating it with sedimen-
tary strata of a much later age. The newest of the two upper slates
noticed in Art. 30 is not found in Arran, and is probably either
thrown out westward beyond the line of bearing of the second slate,
or is so altered by the near proximity of the granite as to be undis-
tinguishable from the middle or dark coloured slate, through whicli
the granite has been protruded. On the east side of the granite
nucleus about Corrie, this slate band is extremely narrow, probably
only a few yards thick in many places ; on the western side it is
much broader, but the underlying mica slate does not appear, and is
not found till we pass into the opposite peninsula of Cantire, where
we meet with it on arriving at the line of bearing which it preserves,

65

as already remarked, in crossing the country from north-east to
south-west. To this succeed the gneiss tracts, which, as we advance
north-west, keep with us till we reach the granite axis of the Gram-
pians. Along this axis, however, it is now known that the granite does
not form an unbroken continuous ridge or line of heights. It occurs
rather in independent elliptic shaped masses, its place on the axis
being often taken by mountains of gneiss, porphyry, or quartz rock.

Such, then, is the singular abnormal position of the Arran granite,
which gives to this island all its peculiarities, both as regards its
geographical features and its geological structure. The protrusion
of so large a body of igneous rock by plutonic fires along the line of
junction of the older slates and the secondary formations, and its ele-
vation to a great height in a space so limited, might naturally be
expected to produce phenomena of varied interest, such as have been
alluded to in the opening paragraph of this section.

45. The granite nucleus occupies by far the greater portion of the
northern half of the island. The three mountain groups already
described, with the glens and valleys penetrating and dividing them,
consist entirely of this rock. It is remarkable, however, that at no
point does the granite reach the sea coast. In its elevation from the
plutonic depths, it bore up with it a narrow band or framework of
clay slate, of the second or dark coloured variety, which completely
encircles the nucleus. The structure of this portion of the island is
shown in the cut annexed, representing an ideal east and west section

(a) Coarse grained granite ; (&) fine grained granite ; (c) slate; (d) old red sand-
stone ; (e) carboniferous strata.

from Corrie to White-Farland. From the mouth of the lorsa water
at Dugarry, round the west side of the island by Imochair, Thunder-
gay, and Catacol, to Loch Kanza, this slate occupies the coast, and
forms a belt of considerable but varying breadth. Its junction with
the granite is seen in almost every stream, and in many points along
the western slopes of the lower hills. It extends all round the preci-
pitous sides of the Loch Ranza valley, and to a short distance east of
Newton point, which forms the north-east angle of the loch, as far
as a small stream called Alt-Mhor. It here retires from the shore,
and forms the high northern ridge already mentioned, the coast from
this point eastwards, and then southwards, being occupied partly by

K

old red sandstone and partly by coal sandstones, beds of carboni-
ferous limestone and of coal and coal shale being interposed amid
the beds of the latter. The band of slate is of considerable breadth
in this northern ridge, but narrows very much on approaching
the opening of Glen Sannox; along the hill sides southward, by
the base of Ciod-na-Oich, and above Corrie it is extremely narrow,
apparently only a few yards in some places. Still farther south,
as it sweeps round south-west between Maoldon and the base of
Goatfell, it gradually widens — presents bold precipices on both
sides of the lower part of Glen Eosa, and along the south border of
the granite nucleus between Loch Ghnuis, Dugarry, and Imochair
attains its greatest development. Here the thickness of the slate
band between the granite and old red sandstone cannot be less than
2,000 or 3,000 feet ; whereas above Corrie, in the bed of a stream,
we noticed a spot where it is not more than ten feet, so close to the
outer margin has the remarkable outburst of granite taken place. It
has indeed been asserted by one -writer, and repeated by others, that
the continuity here is entirely broken, and that the granite is in con-
tact with the old red sandstone. This we consider is decidedly a
mistake. In frequent summer rambles along these romantic hill
sides, we have examined carefully every open section, and have never
seen such a contact. In the spot referred to, the rock is a hard
bluish-gray, flinty slate, very like a hard sandstone when taken wet
from the burn. The strata here come against the granite end-on,
or nearly at right angles. The prevailing dip of the slate over the
whole district is the same as that which it maintains in adjoining
tracts beyond the limits of Arran, namely, south or south-east at a
high angle ; it is not arranged in mantle-shaped strata around the
granite nucleus, but is inclined towards it in some places, and off
from it in others. Thus along the north side of the nucleus from
North Sannox to Catacol, the dip is south or towards the granite, at
angles varying from 65° to 75°. This is of course unconformable
to the granite centre ; but a like dip and inclination on the south
side give conformability ; and here, accordingly, from Maoldon by
Glen Eosa and Dugarry, and perhaps even as far as Thundergay, the
slate is seen to recline against the sides of the granite mountains in
a kind of mantling stratification. In many spots there is great con-
tortion and irregularity, indicating the operation of violent forces,
attendant on the upheaval of the granite. Reference will again be
made to several of these cases, as well as to local variations in the
mineral character of the slate.

46. Within the granite tract, whose limits are defined by the

67

slate as above described, there occur two distinct varieties of the
rock — a coarse and a fine grained, not intermingled with one another,
but occupying separate portions of the district. Mr. Ramsay called
attention to these marked varieties, and traced approximately the
limits of each. We have somewhat extended the bounds of the fine
grained variety. It occupies the space between the Ben-Varen and
Cior-Mhor ranges, rising high up on the east front of the former, and
on the west front of the latter reaching as far up as the passes from
Glen lorsa into Glen Rosa and Glen Sannox. It crosses the water-
shed at Loch-an-Deavie, and stretches from half a mile to a mile
north-east toward the base of the Castles, and down also into Glen
Eais-na-Vearraid. The coarse variety covers the rest of the district,
and forms the tops of all the mountains. The Goat fell group is
composed entirely of it ; as are also the whole east front and all the
summits of the Cior-Mhor range from Ben-Ghnuis to Suithi-Fergus ;
along the back of the range the fine grained variety reaches the
heights already noticed. Extending hence across the valley of the
lorsa, it rises on Ben-Yaren as high as the base of the last steep
ascent. The rest of the range is of the coarse variety. The two
kinds are very distinct from one another, though the component
minerals are the same. Both consist of quartz, felspar, and mica,
the two first being in nearly equal proportions, the last in less quan-
tity than either. In neither kind is this mica replaced by horn-
blende, so as to form the variety called syenite. This rock is indeed
found in Arran, but not within the district called the granite nucleus.
There are, however, several varieties of both kinds ; but these are
merely dependent upon slight changes in the colour or size of the
constituent crystalline grains. The fine variety of the interior has
often an arenaceous aspect and sandy feel, from the minuteness of
the grains. The distinctness of these two varieties of granite in
their mineral aspect, and the fact that they do not intermingle, but
occupy separate tracts, led Mr. Ramsay to conclude that they were
of different ages, and that this fine grained variety was the newest
rock in the whole island. He rests this conclusion on the non-exis-
tence of whin dikes in the fine granite, and on what he seems to state
with the confidence of personal observation, namely, that " in cut-
ting through the coarse granite, these dikes frequently approach the
borders where it joins the fine variety, and are then invariably cut
sharply off by the fine granite, when they approach it in the coarser
kind," (p. 65). We have never noticed any instance in which a
dike is thus cut sharply off, nor does Mr. Ramsay refer to any spot
where such a case occurs, and it is possible he may refer merely to

68

the non-existence of dikes in the fine granite, while they are often
met with in the coarse. He states his view with some diffidence,
and with the qualification that the tract of fine grained granite has
not been carefully investigated with respect to these appearances.
This examination was made by us last summer ; and the result was
the discovery of several trap dikes, ranging between north and north-
west across the tract of fine grained granite; but the intersec-
tion of these with the coarse grained variety could not be observed,
nor has such intersection been anywhere noticed by us. It is quite
possible, however, that there may be one system of dikes in the
coarse granite cut off by the fine, and another system in the fine
itself. If the intersection does indeed occur in the manner men-
tioned in the above quotation, the conclusion will be forced upon us
that the fine granite is of later eruption than the coarse, and also
later than the dikes in this coarse variety. There would thus be
granite of two ages, and trap of two ages, in this central district.
We must, however, express our belief, that the discovery of trap
dikes traversing the fine granite for considerable distances renders it
extremely probable that they are continued both ways into the
coarse variety ; and that, while the two granites may "be of different
ages, the dikes are of one age and posterior to both granites. We
shall have occasion hereafter to refer to the age of these two granites.
The veins of fine granite, which are so frequently found traversing
the coarse granite of Groatfell, Ben-Grhnuis, and other localities, are
certainly cotemporaneous, formed by chemical affinities or electric
forces acting in some peculiar way during the consolidation of the
rock, and not injected from below at a later date. In many cases
indeed they are seen quite isolated in a granite block. Sir Charles
Lyell, who "himself examined a great part of Arran in 1836,"
adopts the view set forth by Mr. Ramsay (El. of Geol., 5th ed.,
1855, p. 590). This view he illustrates by a cut (p. 591), which is
slightly inaccurate, as the facts above stated will show. The fine
granite does not rise into mountains, co-ordinate with those formed
of the coarse variety ; the fine grained is actually traversed by dikes
of common trap through considerable distances ; and we contend
that evidence is wanting to prove the injection of veins of the fine
variety into the coarse. An error in one of Mr. Ramsay's sections,
at the points 5, f, is also copied into this cut, to which we shall
again refer.

47. The encircling band of clay slate is succeeded on the east and
south by a band of old red sandstone, which, like the slate band, is
of irresrular breadth. It begins to overlie the slate at the Fallen

69

Kocks on the north-east coast, and occupies the shore thence to the
inarch of Achab farm, half a mile north of Corrie. Here it retires
inland, the carboniferous formations taking its place on the shore ;
is interrupted for a short space, south of Corrie, the newer sandstone
then resting on the slate; is again resumed on the west base of
Maoldon, and stretches thence continuously westward, around the
border of the slate to the mouth of Mauchrie water. Between this
point and Dugarry, near lorsa waterfoot, it attains its greatest
breadth. The breadth is also considerable from the Fallen Rocks to
a point a little south of the base of Ciod-na-Oich. A line from the
north side of Brodick bay to Dugarry very nearly marks out its line
of junction with the slate. The structure varies from a fine grained
red sandstone to a coarse conglomerate or pudding-stone, in which
the fragments are more than a foot in diameter. The coarse and
fine strata do not follow any particular order, but alternate through-
out the formation, indicating the operation of powerful currents, and
intermediate periods of repose. The imbedded fragments in the con-
glomerate are mica slate from a distant source, the ordinary slate
adjoining, and quartz of two varieties, of which one is the common
white quartz, forming veins in the slate, and the other a peculiar
resinous quartz, of a cinnamon colour, not found in Arran, and of
which we know no locality. This latter is rounder and polished,
while the other is often angular or slightly rounded. The resinous
variety is exactly the same as fragments which occur abundantly
and of large size in the conglomerates of the east coast of Antrim,
but not found in situ anywhere in the north of Ireland. It is diffi-
cult to account for the appearance of these in the conglomerates ;
they may have some distant source among the Grampians. It is
remarkable that fragments of granite do not occur in the conglome-
rate ; none of the Arran sandstones have as yet yielded a piece of this
rock to any observer. The conclusion to be drawn manifestly is —
that when these sandstones and conglomerates were in process of
formation by the wearing down of the slate rocks and the transport
of the fragments by water, the granite of the interior was not exposed
to disintegrating causes, but remained as yet in hypogene depths, pro-
tected most probably by the enveloping slate rocks. Facts to be
stated farther on will throw light on this curious subject. It may
here be merely noticed, that the sandstones of the coast have the
edges of the strata turned up towards the central granite, and that
north of the mouth of North Sannox water, the dip is towards the
north-east and north, while south of this point it is south-east and
south. Beds of limestone occur subordinate to the old red sandstone,

70

at the march of Achab farm, at Glen Laodh on the hill side south of
the road from Brodick to Shiskin nearly opposite Moniquail farm,
in Clachan glen, and a few other places. They are without fossils,
and similar to the cornstones already noticed in Arts. 27, 28, 35, 38.
We shall again refer to them in our separate " Excursions."

48. The southern half of the island, southward of the old red
sandstone boundary above denned, that is, from the String road and
valley of Mauchrie water to the South End, is composed of several
members of the carboniferous series, broken through and overlaid by
various igneous rocks, chiefly those of the greenstone type. The
prevailing rock and substratum of the whole southern plateau is red
sandstone, varying from a fine compact structure to that of a coarse
conglomerate. A narrow band of this sandstone extends also along
the eastern shore northwards to Corrie ; and again from the Fallen
Rocks north-west to the Scriden at the northern extremity near the
entrance of Loch Ranza. Subordinate to this sandstone are beds of
limestone, abounding in fossils of true carboniferous types, beds of
shale and coal, in which are found fossil plants and shells, such as
characterize these strata in the basin of the Clyde. The structure
indeed is quite analogous to that of the Clyde basin, the peculiarities
of which have been already explained in Art. 24. The limestone
does not occur at the base of the system, nor does it occupy any
determinate place in it, but is found throughout the whole series of
beds in repeated alternations with the sandstone and shales. These
alternations are seen in section on the sea shore along the east border,
on the hill side between Corrie and Brodick, along the high grounds
on both sides of Glen Cloy, in Clachan glen, Glen Scorodale, and
other water channels issuing westward ; and in the Alaster water
above Lamlash, they descend almost to the bottom of the glen,
where alluvial deposits obscure the old rocks. On this ground we
refer the whole of the strata of the southern division of the island to
the carboniferous series. The alternations in question are not seen,
it is true, on the Corriegills, Whiting bay, or Kildonan shores, nor
do they appear among the sandstones of the South End ; but such
massive strata of red sandstone as appear along the east and south
shores, are common in the carboniferous system, and form indeed
everywhere its prevailing member. They are conformable to the
strata inland, in perfect sequence with them, of the same mineral
structure, and without any fossils of New-Red types. We do not
therefore hesitate to refer them all to the carboniferous system ; and
we are persuaded that the distinguished geologists who established
such a classification for Arran, will be the first to agree in this view.

71

The Outlying Granites.

49. Perhaps the most remarkable feature in the geology of Arran,
is one made known by its recent explorers, and of which the British
Isles offer, we believe, only one other example. We refer to two
outbursts of granite amid the sandstones of the southern division
of the island, noticed in the last Article. One of these was dis-
covered by Mr. Eamsay in 1837 ; but the first description of it was
published in 1839 by M. Neckar, who named the district Plover-
field. The other was discovered by the writer of these notices in
the summer of 1855, and described in the autumn of that year at
the Glasgow meeting of the British Association. Both tracts occur
on that side of the sandstone district which is nearest to the " granite
nucleus;" and the occurrence of the rock here is thus intimately
related to the outburst of the central granite, in its abnormal posi-
tion— close to the outer border of the upper slate, and to the base of
the sandstone formations — already pointed out as the great leading
peculiarity of Arran. These tracts are represented in the annexed
ideal section from east to west between Corriegills and the valley of
Mauchrie water, the horizontal extent of the intervening sandstone
being much contracted : —

(a) Granite of Ploverfield ; (6) new granite tract at Craig- Dhu; (c) old red sand-
stone of Mauchrie water ; (d~) sandstone with beds of limestone, the whole of car-
boniferous age; (e) eruptive rocks of Doir-nan-Each, the highest hill in the west district
cfthe south section of the island, chiefly porphyry and highly hornblendic basalts.

The Ploverfield Granite.

50. The Ploverfield granite occurs amid strata which undoubtedly
belong to the carboniferous system. The tract is situated on the
west side of Glen Cloy, and that branch of it called Glen Dhu. The
hills here are the highest portion of a long ridge running up south-
west from the plain of Brodick, and dividing Glen Cloy from Glen
Shirag. At the origin of this ridge, are beds of carboniferous lime-
stone with fossils, under the north wall of the enclosure of Brodick
church. On the upper slope of the ridge, beds of limestone and
shale also occur in the sandstone, not far from the north base of the
Windmill hill — a high, elongated, narrow ridge, steeply overhanging

72

Glen Dhu, and composed of quartziferous porphyry. On its south-
west base, the granite first appears, separated, in some places at least,
from the porphyry by a narrow band of altered sandstone. Thence,
keeping at a high level, it extends along the hill slopes at the head
of Glen Dhu, and terminates southwards against a ledge or low
cliff of syenitic greenstone, a little west of the top of the Blackhill —
a high, bold point running forward between Glen Dhu and the upper
part of Glen Cloy. The top and front of this hill toward both glens
are composed of altered sandstone, resembling quartz rock, the
change of structure being, no doubt, due to the proximity of this
syenitic greenstone. The ledge or cliff seems to be the northern
front of a large dike ranging between west and north, and cutting
off the granite. To the south of it, the hills are composed of sand-
stone, with occasional knolls of overlying common trap. Westwards,
the granite extends across the moorland tracts, which lie between
Glen Cloy and a high ridge forming the watershed or axis of the
island at this part. It is seen in a few rocky points, but chiefly
rising through the sandy substratum of the peat, where this has been
worn away, or in the beds of the small streams. As we advance
westwards, it becomes gradually intermingled with S3renite and
porphyry ; but the relation of the three rocks cannot be made out,
owing to the nature of the ground. They appear to alternate, the
granite diminishing in quantity toward the west. On the summit
of the highest ridge or watershed, loose pieces of granite strew the
surface, mixed with syenite and porphyry. Bosses of the latter rise
through the broken-up masses of the sandstone, forming the main
body of this ridge. The surface is also strewn with masses of pitch-
stone, and of the coarse grained granite of the northern mountains.
Such must be taken as the hypothetical boundary of the Ploverfield
granite on the west. Its south boundary does not reach so far as a
line joining the heads of the Clachan glen and Glen Cloy, sandstone
being seen continuously between them. On the north side its
boundary runs from the west base of the Windmill hill to a point a
little west of the summit level of the String road. Here a high
ridge on the south side of the glen, and west of the watershed,
presents granite in its upper part ; the lower portion, on the level of
the watershed, is composed of sandstone ; but the junction is not
seen. These limits mark out an area much larger than that
assigned to the granite in Mr. Ramsay's map and descriptions. He
states, indeed, his inability clearly to define it. " From the depth
of the moss on the flat surface of the hills, the boundaries of this
granite have not yet been determined ; but by a little labour, property

73

bestowed, this object might doubtless be accomplished." — (Guide to
Arran, p. 12). The weathered surface of the granite is generally
white ; but the prevailing colour in a fresh fracture is red. It is
fine grained, with little mica in proportion to the quartz and felspar,
and is very similar to the fine grained variety of the interior. Drusy
cavities often occur, lined with crystals of quartz and felspar. Mr.
Ramsay states (p. 12), that "It sends forth veins into the adjacent
sandstone; while specimens of the sandstone, much altered by the
effects of intense heat, may even be found enclosed in the granite."
We have not noticed these cases of intrusion ; nor are the precise
spots mentioned, so that we might verify them. We have, however,
seen such in connection with the porphyry of Windmill hill, to which
the granite succeeds on the west, and also in connection with the
new granite tract to be next noticed.

The Craig-Dhu Granite.

51. The other granite tract lies on the south side of the Shiskin
road, nearly opposite the farm house of Glaister. Here the hill, whose
base is skirted by the road all the way down from the " String,"
overhangs the valley of Mauchrie water in a steep cliff called Craig-
more, Craig-Dhu, or The Corby's Eock. This cliff is the outer
edge of a small plateau or table land, cut off from the higher ground
behind, towards Doir-nan-Each, by a deep hollow which completely
isolates it. The summit is 700 to 800 feet above the valley, and is
more than a quarter of a mile long, by one to one and a-half furlong
broad. It descends steeply towards Shiskin on the south-west, and
slopes gradually north-east towards Moniquail. The summit and
sides of this plateau are formed of fine grained granite, very similar
to that of Ploverfield. The base of the cliff towards Mauchrie water
is covered by a long talus of granite blocks and smaUer fragments,
reaching to within 200 or 300 yards of the road, and appearing even
at that distance of very different aspect from fallen masses of sand-
stone.— See last cut, b, c.

The granite here seems to rise either through the old red sand-
stone, or at the junction of this rock with the carboniferous strata.
The granite is nowhere seen in situ at a low level ; the talus before
mentioned obscures the rocks along the base of the hill ; and the
ground by the roadside, and along the valley, is deeply covered with
alluvium. At one spot only could we detect any rock in situ. Im-
mediately below the bridge, by which the road crosses a small
stream, the water runs over a projecting mass, which seems to be
either a serpentine, a greenstone with much felspar, or an iron-shot

74

claystone. But at a high level on the west, south, and east sides
of the plateau, the granite is seen to rise through a coarse conglo-
merate ; and numerous contacts are observable. These are highly
interesting, and clearly indicate the intrusion of the granite sub-
sequently to the formation of the conglomerate. The base of this
conglomerate is a coarse sand, and the imbedded fragments sand-
stone, quartz, and granite. The base is highly indurated, and assumes
a porphyritic structure; the sandstone is rendered crystalline, and
the quartz has been fused, and reconsolidated into a substance
resembling porcellanite. The fragments of granite are of an elliptic
form, less rounded than the quartz, and are exactly like the adjoin-
ing mass of granite in structure and component parts. Whence have
these granite fragments been derived ? From the body of fine
granite among the northern mountains, or from the adjoining mass
itself? Mineral structure does not enable us to determine — the
two rocks are so similar. If from the former source, then we must
conclude that the granite of the interior was elevated so as to
be exposed to disintegrating causes, while the conglomerate was
forming; in which case granite fragments ought to occur abun-
dantly in the sandstone conglomerates ; but this is not found any-
where in Arran ; — a fact noticed by all observers. Even here the
fragments occur only in close proximity to the granite itself. Must
we not then rather suppose that pieces of the granite adjoining,
when this rock was erupted in a fluid or semi-fluid state, were
injected among the outer strata of the conglomerate, also fused by
the contact, and so became imbedded in these strata only ?

52. Granite, then, occurs in Arran, in three disconnected tracts,
amid slates in the northern mountains, in the old red sandstone of
Craig-Dhu, or at the junction of this rock with the carboniferous
strata, and also amidst these carboniferous strata at Ploverfield. In
each of these positions it is clearly posterior to the rock which
encircles it ; for it is intruded among these sedimentary deposits, and
produces a marked alteration upon them along the planes of contact.
We have, therefore, now to consider the question of age. Are the
three granites of three distinct ages corresponding with those of the
strata among which they intrude ? or were they erupted simultane-
ously, so as to pierce through the three formations during one and
the same period of disturbance ? In other words — and this view
narrows the question — since the Ploverfield granite is clearly of later
origin than the sandstones of Windmill Hill, and the shell lime-
stones subordinate to them, were the granites of Goatfell and Craig-
Dhu erupted at the same time with it ? or does their injection

75

among the strata, and elevation to the day, date back to an earlier
period ? The close proximity of the Craig-Dhu granite to the border
of the carboniferous formations, if it be not actually enclosed in these,
evidently points to an identity of age with that of Ploverfield, and
renders their simultaneous eruption extremely probable. How then
is the Goatfell granite related to the old red and carboniferous for-
mations ? It has been long established, and is well known that it
everywhere throws powerful veins into the encircling slate-band
around the borders of the northern district, greatly altering the slate
along the line of junction, and disturbing its stratification. The slate
is manifestly heaved up by it ; and in some vertical sections, as at
Tormidneon, and the hill sides north of Glen Catacol, we have slate
above and granite below, with numerous alternations where the two
rocks approach. The granite was, therefore, injected in a molten state
amid the already formed strata of slate. But, further, it was sug-
gested long ago by Murchison and Sedgwick, in their celebrated
paper on Arran (Geol. Trans., vol. in., second series, 1835), that the
bed of limestone on the north point of Maoldon may have once been
continuous with the Corrie stratum, and that its actual position is
due to an upthrow by a protruding mass of granite advancing from
the central mass east of Goatfell. If this be admitted, it would make
the intrusion of the granite posterior to the deposition of the car-
boniferous formations, and so render probable an identity of age
between the Ploverfield granite and that of Goatfell. We think,
however, that this view is liable to question ; we often find exactly
similar bands of limestone amid the strata of coal sandstone, without
any evidence of former continuity, or such cause of disturbance;
and the amount of vertical displacement implied in the supposition
could hardly have taken place here without a fracture of the
crust, and the appearance of granite on the surface, — so narrow is
the band of sedimentary strata superimposed upon the granite. A
positive conclusion, then, seems scarcely justifiable from -this case.
A stronger presumption is derived from the high angle generally
assumed by the sandstones, when they approach nearest the granite,
on account of the narrowness of the slate band along the Corrie dis-
trict. An extremely interesting junction in the Sannox burn throws
an unexpected light upon this question of relative age. A few hun-
dred yards above the Barytes mill a narrow band of slate crosses the
river at right angles, between the granite on one side, and the old
red sandstone on the other. The slate is very much altered by the
close proximity of the granite ; it has, in fact, the structure and aspect
of Lydian stone or basalt ; and the sandstone also has a highly meta-

76

morphic structure, firmly adhering to the slate, and intermingling and
interlacing with it, as if the slate had been forcibly injected among
the strata of conglomerate in a melted state. This interesting junc-
tion seems to have escaped notice, till observed by us, in the summer
of 1856. Something analogous, though less striking, is seen towards
the junction in the burn of the White water, above Corrie, where a
gradual passage takes place from slate to sandstone, clearly the effect
of metamorphism, by the heat to which both were subjected. The
facts clearly show the posteriority of the granite outburst to the
deposit of the old conglomerate, and that the entire slate stratum
on the east or Corrie side was in a plastic state, under the influ-
ence of the intense heat which fused the granite.

Viewing all these facts in connection with the general conforma-
bility of the carboniferous strata to the old red sandstone, and the
gradual transition from the one series to the other, observed in seve-
ral places, there seems a great probability that the injection of the
granite, in a melted state among the strata, took place after the
deposit of the carboniferous formations ; and that therefore the gra-
nites of the three disconnected tracts may be all of one age, or belong
to the same period of disturbance. But as the granite of the nucleus
is nowhere seen to alter the carboniferous formations, while it cer-
tainly does, as above stated, alter the old red sandstone, it is quite
possible that these carboniferous strata may have been deposited
upon the old sandstone during a period subsequent to the irruption
of the granite. But this irruption took place in hypogene depths,
not only prior to the elevation of the island above the waters of the
primeval ocean, but while the granite was yet enveloped by the
mantling slate rocks, and perhaps also by the later formations. It
is obvious, as already pointed out in Art. 47, p. 69, that these
secondary strata have not derived the detrital materials of which
they are made up from the disintegration of the granite ; this rock
was yet protected from disintegration by its mantle of slate ; and the
old red derived its materials from other, and some of them remote
sources. An extensive disintegration and denudation may even have
gone on for a long period, ere yet the strata were injected by the
molten granite ; for this injection, we have seen, alters the conglo-
merate^ partly made up of slate fragments, through the medium of
the fused or semifused slate ; and besides, the extreme narrowness of
this band on the east renders it very improbable that portions of the
injected veins, with adhering slate, should not be found in the con-
glomerate, if the injection had been prior to the denudation and to
the deposit of this latter rock. The elevation of the central granite

77

mountains to their present height may have been a gradual process,
during the continuance of which, in waters constantly becoming
shallower, the strata of slate may have been exposed to further
extensive denudation, which, joined to various atmospheric influences,
afterwards acting, would give their present form and outline to
the jagged ridges of the northern mountains. Long before this
elevation took place, the granite, under the pressure of the superin-
cumbent slate, and perhaps of the newer formations also, had acquired
its crystalline structure by the slow passage of its heat of fusion into
the adjoining strata ; and most probably it was quite solidified ante-
riorly to its elevation, so that it was protruded in a solid form.

53. The agent in this protrusion may have been a newer granite,
produced beneath the former. Let fresh accessions of molten matter
— the matter of granite — be slowly and constantly transfused from
the nether depths, amid the basement portion of the older granite,
already cooled and crystalline above, while fused below by contact
with the molten mass, — this latter will expand, and perhaps later-
ally extend the former, and raise it in a solid form. Thus a great
upward movement might be produced, forming the high mountain
nucleus of the north, and at the same time elevating and contorting
the strata of slate and sandstone resting on the flanks of the older
granite, and in some places perhaps even inverting the dip of the
slate, as being subject to a greater strain, and more likely to yield en
masse, without disruption ; while the sandstones of the southern pla-
teau, remote from the focus of intensity in the upheaving force,
would be elevated from below in more horizontal strata. The newer
granite below might likewise impenetrate the older, and so make its
appearance in lower situations, when the land was finally raised, and
had assumed, in virtue of denudations effected during the process,
and by causes afterwards acting, somewhat of the aspect which it
now retains. Formed under such conditions, this later granite
might be expected to differ in structure, if not also in composition,
from the older granite, invaded and displaced by it. Such differ-
ences we know do actually exist between granites in the Alps, Andes,
and other localities, which can be clearly proved to be of different
ages. Now, we have two such granites within the area of the moun-
tain nucleus — the coarse and the fine-grained — whose limits have
been already described, and whose mineralogical differences, as ori-
ginally recognized by MacCulloch, have been pointed out (Art. 46).
It is with this latter, or fine grained variety, deficient in mica,
that Mr. Ramsay's Ploverfield and our Craig-Dhu granite almost
exactly agree (Art. 50, 51). Is it not, then, probable that these

78

three belong to one period of disturbance — tbat they were simulta-
neously injected amid the rocks which now enclose them, at a period
subsequent to the deposit of the carboniferous strata? But the
evidence for this conclusion is incomplete without a decided example,
along the line of junction of the coarse and fine varieties in the inte-
rior, of veins from the latter penetrating the former. Such a case
has never been seen by us, or recorded by any observer, as already
noticed (Art. 46, p. 68). Its discovery would amply repay the
trouble of a careful search, and render much more probable the pos-
teriority of the fine variety. Much also depends on the view which
may be taken respecting the rounded pieces of fine grained granite
enclosed in the conglomerate, close to the Craig-Dhu granite (Art.
51). If our explanation of their occurrence there be deemed unsatis-
factory, then will not the above conclusion hold ; and it must be
admitted that, before the irruption of the Craig-Dhu granite, the
fine grained variety of the interior must have been elevated, stript of
its slate covering, and exposed to degradation.

54. What, then, it may be asked, is the conclusion which we
favour, and to be finally drawn from these various and somewhat
conflicting statements ? The discussion may seem tedious and unim-
portant to many ; yet we hope it will not be without its use to the
student and future inquirer ; and as several of the facts are new, it
may have some value in the eyes of the many geologists in this and
other countries, who have either written upon the subject or take a
lively interest in the physical history of this extraordinary island.
The question of relative age is, we hope, much narrowed by these
statements, but for the present must remain unsettled. The various
possible conclusions may be set forth, by way of recapitulation, as
follows : —

1 . The oldest rock in the island is the slate.

2. The old red sandstone and the carboniferous sandstones, with
their intercalated limestones and coal strata, were formed before the
granite was exposed to disintegration, the only fragments of this
rock yet found being those in close proximity to the Craig-Dhu mass,
of which they are probably injected pieces, and not derived from the
disintegration of a granite already exposed.

3. The injection of the granite of the nucleus, that is the coarse
grained or Goatfell granite, in a molten state, amid the slate strata,
was certainly posterior to the deposit of the old red sandstone, and
may have been posterior also to that of the carboniferous strata.

4. If the granite of the nucleus be thus of later age than the car-
boniferous strata, then may ah1 the three granites be of one age, such

79

differences of mineral structure, or aggregation of parts, being often
seen in granites certainly cotemporaneous.

5. But as the coarse grained granite cannot with certainty be pro-
nounced newer than the carboniferous strata, while the Craig-Dhu
and Ploverfield undoubtedly are so, then we may have two ages
for these outbursts — one for that of the granite of the nucleus, and
another for that of these latter.

6. The constant character of the fine grained granite of the inte-
rior, through a considerable area, and its subordinate position to the
coarse, point to a later origin than that of the latter ; while its almost
perfect identity in structure and arrangement of parts with the other
two granites render very probable the cotemporaneity of these three,
and their posteriority to the coarse grained variety. This conclu-
sion, which is extremely probable, and to which we chiefly incline,
would be greatly strengthened by finding decided veins of the fine
variety penetrating the coarse, along the line of junction. The mere
occurrence of veins of fine grained granite amid the coarse variety is
insufficient. Their connection with the inferior masses, and altera-
tions at the line of contact, similar to those at the slate junctions,
are the points to be determined. Already, we think, sufficient
evidence has been set forth (Art. 46, p. 88), to show that this fine
grained granite is not the newest rock in the island, but is older than
the traps and porphyries. — To a short history of these we now pro-
ceed.

TJie Trappean Rocks.

55. Arran is extremely rich in rocks of this class ; most of the
known species occur, and also those numerous varieties by which
these graduate into one another. They form great overlying masses,
capping the sandstone of the southern plateau, and rising into the
highest hills of this division of the island. They are interposed
amid the sedimentary deposits, in huge sheets or beds conformable

Relation of the Igneous and Sedimentary Rocks.

to the stratification, and cut through all the rocks alike, from the
lowest to the highest, in vertical or slightly inclined dikes, which
range continuously across great horizontal distances, in one uniform
direction. These dikes are never observed to wedge out downwards ;
and no doubt they descend into the hypogene depths, where sheets

80

of molten matter still exist, concentric with the crust — the common
source whence they all proceeded, and whose vents or outlets these
dikes once formed, in past stages of the earth's history, when the
various rocky materials were elaborating beneath the primeval ocean.
The pressure of a great depth of that ocean, or of other strata, amid
which they were poured out, gave these various igneous products
that density and compactness, which constitute almost the sole differ-
ences between them and the modern products of fire thrown out
under the pressure of the atmosphere only. They differ little in
their chemical composition — mainly in that arrangement of com-
ponent parts which would be given by different rates of cooling from
a state of fusion, to which reference has been already made in previous
portions of these notices (Art. 31, 37, 40).

56. The trap rocks of Arran may be ranged under three classes, —

The Felspathic, comprising porphyry, claystone, compact felspar,
and pitchstone.

The Hornblendic, as basalt, greenstone, clinkstone, and amyg-
daloid.

The Hornblendo-felspathic, as syenite and trap-porphyry.

These are all intimately connected, one species often passing into
another by regular gradations, and they are all found in the same
relative positions with respect to the sedimentary strata. Among
themselves they do not preserve any order of succession, nor do they
occupy separate areas, so that their continuity cannot be reckoned
on through a considerable space. Nor can they be indicated on a
map by distinct colours, so intimately are they blended with one
another. Basalt, greenstone, and trap-porphyry are by far the most
abundant, as well in overlying masses as in dikes and interposed
beds. Porphyry is next in abundance, and occurs in all these posi-
tions ; pitchstone alone has not overflowed the surface, and occurs
only in dikes and beds. The overlying masses are limited to the
southern section of the island, while dikes occur everywhere, not
however with the same frequency in all parts. On this subject
Professor Phillips was, we believe, the first to offer a good gene-
ralization :— " Dikes are most abundant at some distance from the
granitic centre. At Corrygills, at Lamlash and Tormore, they
are exceedingly abundant in the red sandstone, while in the north-
eastern face of the island, where that rock is nearer to the granite,
fewer dikes appear ; and about Loch Eanza the slate is still less
divided by them. Perhaps we may venture to add another gene-
ralization,— viz., that these dikes are most abundant beyond the
line of violent flexure of the strata from their horizontal position.

81

After measuring with care the directions and breadths, and noting
the characters of forty-four dikes, chiefly of greenstone, between
Brodick and Lamlash, and also those at Tormore, it did not appear
to us that any other dependence of the direction of these dikes upon
the local centre of the granitic eruption could be traced." — (Man.
ofGeol, 1855, p. 505.)

Kocks of the felspathic types, which are most closely allied to
granite, seem to have no more intimate relation to the granitic centre
than have those of the hornblendic. The largest body of porphyry
on the island is that of Leac-a-breac, on the south-west; the
next in extent is that of Dunfion, over the Corrygills shore. A
similar rock occupies a small space on the Windmill hill, over Grlen-
cloy, in close connection with the Ploverfield granite. A different
variety forms the bold precipices of Drumadoon, on the west, and the
principal mass of Bennanhead, on the south. The largest body of
claystone forms the middle and upper portions of Holy Isle, and has a
thickness of nearly 900 feet ; extensive beds and dikes of the same
substance are met with in Lamlash river and at Blackwater-foot ;
lesser veins and beds in many other places. All of these cut through
or overlie the carboniferous formations of the southern section of the
island ; the northern section, the region of granite, slate, and old red
sandstone, is almost devoid of these felspathic rocks ; a few dikes only
are met with ; almost all those in this tract being of hornblendic rocks.
The pitchstones also, exclusive of those in the granite, are almost
all met with in the neighbourhood of Brodick, and towards Mauchrie
water on the opposite shore. These various felspathic rocks thus
seem to correspond pretty nearly on opposite sides of the island, and
to have no relation, in their position, to the granitic nucleus. Neither
does there seem to us any good foundation for a generalization put
forward by some writers on Arran, that rocks of this type are more
abundant on the western than on the eastern side of the island.

Overlying rocks purely hornblendic, as basalt and greenstone,
occur chiefly over the central and south-eastern portions of the
southern plateau, south of the parallel of Lamlash. North of this
line too great an extension has been hitherto given to these rocks ;
they merely cap the sandstone in isolated knolls or narrow bands of
inconsiderable thickness. The details regarding these, as well as the
felspathic rocks, will be seen upon the map, and will be more fully
noticed in the several " Excursions" which follow. Under the same
head we shall notice the changes made by the dikes on the adjoining
rocks.

In Arran, as elsewhere, almost all the dikes are simple — that is,

M

82

composed of one kind of rock ; while a few, of which the most re-
markable are those of Tormore, are composed of parallel bands of
different substances. By far the greater number, in every part, con-
sist of common trap, that is, some variety of greenstone or basalt.

57. M. Necker, who visited Arran in 1839, carefully measured
the direction by the compass of a great number of dikes seen along
the eastern shore and in the interior, and laying these directions
down upon a map, he identified a great many of them at remote
points. Such continuity has been often made out through distances
greater than the whole length of Arran ; but we know of few tracts
pervaded by dikes, where the same caution is required in drawing
such conclusions, on account of the varying directions of the dikes,
and the undulations to which the same dike is subject. The pre-
vailing direction is towards the north-west and north-east quarters,
and nearly within the limits between which the magnetic needle is
known to vary. Yet are there many which range without these limits,
and not a few have a direction nearly due east and west. Most of
the dikes are vertical ; those which are inclined to the horizon seldom
pass an angle of inclination of 20°. M. Necker estimates the num-
ber of dikes between Loch llanza and King's-cross point at 200 ; the
number to the south of this, on the east coast, at 144 — making a
total of 344. The remaining portion of this estimate we give in
his own words : —

" Mais 1'evaluation precedente ne comprend que les dykes de la
surface d'une moitie environ de 1'ile; tout 1'interieur de la partie
meridionale n' y est pas compris, non plus que la c6te N. 0., ni le
groupe granitique de Ben Vearan entre cette c6te et la riviere Irsa ;
et quoiqu' il soit connu que 1'interieur des terres renferme toujours
moins de dykes que les cotes, et que la c6te N. 0. est en general
tres depourvue de dykes, quoiqu' enfin cette moitie de 1'ile soit bien
plus petite que cette que j'ai parcourue ; omettant ces circonstances
je porterai pour elle un nombre egal a la premiere — soit 344, form —
ant un total de 688, ou, en nombre rond, de 700 dykes de trap dans
la totalite de 1'ile de Arran. Doublant meme encore ce nombre si
Ton vouloit, pour y comprendre tous les dykes caches par les bruy-
eres vastes et etendues dans 1'interieur, par les greves de sable sur les
rivages, ou places dans des recoins inaccessibles des montagnes, on
n'arriveroit pas encore au nombre de 1,500 ; et pourtant en parlant
de telle ou telle cote, de telle localite d'Arran, il est souvent echappe
a ceux des geologues qui ont decrit Arran, a moi-meme peut-etre
tout le premier, de dire qu' on y voyoit des innombrables dykes de
trap. Or, je crois avoir maintenant montre" que, loin de ne pouvoir

83

6tre comptes, on peut a present concevoir 1'esperance de voir chacun
des dykes de cette tie individuellement e"tudie", numerote, decrit et
enregistre" dans un catalogue descriptif et raisonne, analogue a celui
que j'ai aujourd' hui 1'honneur de mettre sous les yeux de la Societe"
Koyale."*

We are not able to state how far this estimate may be correct. No
one has followed out the suggestion made in the last sentence ; the
labour implied in the inquiry would scarcely be rewarded by the
scientific value of such a catalogue.

Mr. James Napier, of Glasgow, has published a short paper on the
dikes between the bays of Brodick and Lamlash in the Edinburgh New
Philosophical Journal, New Series, vol. ii., No. 1, July, 1855, accom-
panied by a map, on which the dikes are laid down. He reckons
altogether fifty-four dikes as visible along the shore, but considers
that not a few may have escaped his notice. " Struck," says Mr.
Napier, " by the large number of trap dikes cutting through the
sandstone, in a direction at right angles to the sea line, it occurred to
me that if such dikes continued round the coast to Lamlash, and still
at right angles to the sea line, they must in all probability have pro-
ceeded from a common centre, lying somewhere between the two
bays." To test this idea by observation, he measured and marked
clown the position of every dike, and the result confirmed his " antici-
pation, that they proceeded from one, or possibly from two centres."
A similar idea would be very likely to occur on examination of M.
Necker's map, which certainly Mr. Napier had not seen, else he
would have mentioned it. The notion of radiation from a common
centre we do not, however, find alluded to in M. Necker's paper.
Mr. Napier seems disposed to assign two centres — one for the fels-
pathic dikes, and another for the hornblendic — both lying inland
towards the Lamlash road. Prolonging the directions of the two
principal felspathic dikes on the shore, he finds that they would meet
near the claystone quarry on the Lamlash road, about a mile from
Springbank ; and here he would place the felspathic centre ; the
hornblendic he does not so definitely fix.

Now, analogies in support of this view can certainly be drawn
from districts of recent volcanic action, where fissures radiating from
a vent, or focus of disturbance, are seen to be filled with basaltic lava
and other igneous matters ; and the same may doubtless have occurred

* Documents sur les Dykes de Trap d'une Partie de 1'ile d'Arran. Transactions of
the Royal Society, Edinburgh, vol. xiv., Part 2, 1840, p. 684. Extra copies of this paper
and accompanying map were thrown off, and are still to be had. It is a model of patient
and generally accurate research.

84

in the case of the plutonic rocks ; but the evidence for it in Arran we
cannot consider sufficient. There are many exceptions to the recti-
lineal course of dikes here as in other places ; some of the dikes con-
verge towards the Corrygills shore, and the largest runs a long way
parallel to it, while one at least re-appears far inland beyond the
place of the supposed focus. Besides, so far from " the whole of the
hills between Brodick and Lamlash being composed of trap," this rock
is, in point of fact, confined to a narrow and thin capping along the
highest ridge between the two bays ; and Mr. Napier has overlooked
the great outburst of porphyry at Dunfion, which has a manifest
relation to the felspathic dikes on the shore, as well as the numerous
masses of claystone intercalated amongst the sandstone strata along
the northern slopes west of Corrygills.

On these grounds we cannot admit that this speculation has any
value ; the apparent radiation arises from the circumstance already
mentioned, that the vast majority of the dikes range between the
points of extreme magnetic declination east and west. Some other
suggestions, however, of this paper have great value ; those, namely,
of a chemical nature, referring to the different degrees of fusibility
and rates of cooling among trappean rocks, which, if carefully
followed up, and experimentally illustrated, might lead to the eluci-
dation of many points still obscure in the natural history of the
hypogene igneous formations.

Glacial Phenomena.

58. The various accounts which we possess of the geology of Arran,
and the separate memoirs upon it, were written before glacial action
had been recognized in the production of superficial phenomena ;
and we are not aware that any geologist has since turned his atten-
tion to the subject. Those phenomena, indeed, had been observed
of which the ice theory is now considered to offer the most satisfac-
tory explanation ; but the island has not hitherto been examined
with the view to discover the direct evidence of the action of ice, such
as striated and polished rocks, and "roches moutonnees." Visiting
Arran in 1855, after having spent two months of the previous
summer in a district abounding in unequivocal evidences of such
action, I felt the greater confidence in undertaking this task. The
result may now be briefly stated ; details being reserved for the
notices regarding particular tracts, which will be given farther on.

The remarkable peak of Cior-Vor, whose altitude is about 2,500 feet,
has been already (Art. 43) pointed out as the geographical centre of
the northern group of mountains. From its base the four great

85

valleys of the island, Sannox, Kosa, lorsa, and Eis-na-Vearraid,
radiate in all directions, their extremities opening on the seaward
belt of low land. If glaciers ever existed in Arran, under the
subarctic climate to which Scotland was once subjected, these
central heights must have been the seat of the snow-fields which
fed them, and the radiating valleys the channels down which
the viscous mass of glacier ice must have pushed forward to
debouch upon the low ground, and melt under a higher temperature.
On the sides, then, and towards the openings of these valleys, we
should expect the effects of glacial action to be most distinctly truce-
able in the striation and polishing of the subjacent rocks and trans-
ported masses, and in the formation of lateral and terminal moraines.
Many broad surfaces of the natural rock are exposed both on the
sides and in the bottoms of these valleys, favourably placed for
receiving such impressions under the grinding action of a descending
mass ; yet have we failed in detecting more than a few cases of
striation and polishing, or of that "moutonne" character of sur-
face, which is referable to the action of moving ice. A granite
surface is, however, very unfavourable for the preservation of
such markings, especially the Arran granite, which is generally
of such structure as to be subject to rapid disintegration. The
slate is better fitted to retain impressions of this kind, its tough-
ness and fine-grained structure rendering it less liable to decom-
position; but it is seldom exposed in favourable situations, and is
rarely found striated. Granite bosses in the glens, and on many of
the lower ridges, have that peculiar rounded character, due to the
action of ice, to which the term "roches moutonnees" has been
applied ; but perhaps none of the cases can be decidedly referred
to glacial action, on account of the peculiar spherical structure so
often assumed here by granite on the large scale. On the slate
ridges, however, beyond the granite border, some well marked cases
do occur, as on the plateau to the south-west of Goatfell. We have
already in previous articles called the attention of the student to
many undoubted instances exhibiting these appearances much better
than anything in Arran.

But though these more direct evidences are so rarely met with
here, there are others scarcely less satisfactory, and of more frequent
occurrence. These are the terraces and mounds of transported mate-
rials on the sides and at the openings of the glens, and the dispersed
blocks in every part of the island.

The terraces and mounds consist of earth and rounded masses of
rock, irregularly mixed without reference to weight, and in such

86

situations, that they could not have been brought together by exist-
ing river action, being much above the level of the streams which
now traverse the valleys. They are most probably referable to gla-
cier moraines of two classes — the lateral and terminal — formed by
masses of rock descending from the highest peaks, and thrown to
either side by the movement of the ice, or deposited at the extremity
of the glacier when the ice melted. The former have been much
modified by torrents entering from the sides, after the glaciers dis-
appeared, and now present but detached mounds. In some glens,
however, as Sannox, terraces yet remain complete, but not of great
extent. The terminal moraines are better marked, fine examples
being visible at the mouths of Glen lorsa, Glen Catacol, Glen
Rosa, and others. The remarkable terraces at the opening of Glen
Catacol skirt the valley on the south-west, at a height much exceed-
ing any level the stream could now reach by the joint effects of
floods and high tides, and indeed surpassing that which it could ever
have attained even when the sea covered the present maritime belt
or terrace. We are therefore inclined to regard these mounds and
terraces as terminal moraines, modified in their outlines by floods,
tides, and ordinary river action.

Still more remarkable are the lofty terraces at the mouth of the
river lorsa ; they are far more striking, indeed, than anything of the
kind in Arran. They consist throughout of transported materials,
some of the rocky masses being very large ; the sides are steep and
the summits usually flat ; and the height of the highest is sixty or
seventy feet above the river, and at least thirty above the ancient sea
level just alluded to. Speaking of these (lorsa and other such
mounds) in reference to river action, MacCulloch remarks : — " The
origin of such alluvia is very obscure — a few may have been depo-
sited in particular situations by the same waters which are now
removing what they formerly laid down ; while in other cases it is
impossible to assign any mode of action by which this double and

opposite effect could have taken place from one agent

The quantity and quality of the materials, their extremely rounded
forms, the nature and permanence of the hills above, and the want
of a regular gradation of size in the stones from the bottom upwards,
seem to show that other causes [than river action] of a transient,
and probably of a diluvian nature, have in distant times generated
those deposits, which have been subsequently acted on by the stream
concentrated on the bottom of the glen by the form of the ground."
—(Western Isles, ii., 335, 1819.) The difficulties of these cases had
thus presented themselves to the mind of this distinguished geologist,

87

and he offers for their solution a vera causa, one certainly capable of
producing such appearances. At that time glacial action had not
been recognized in these countries ; and he offers the best explanation
that could then have been given. The action of ice is, however,
more simple, rational, and consistent, not only with these appearances,
but with others to be presently mentioned.

Similar mounds occur, but not in the terraced form, at the open-
ings of Glen Sannox and Glen Rosa, much elevated above the river
beds. Some way up the latter, also, there are remarkable mounds,
in a situation where, from a great bend in the glen, we should expect a
moraine to be thrown down. Many other examples might be given ;
but it is unnecessary to refer in greater detail to phenomena of this
class. A closer examination of the contents of the mounds and ter-
races, which are limited to the rocks of each particular glen, has led us
to modify the view already expressed (Art. 13) regarding their origin.
We admit, however, that the few decided cases of striation, such as
are so frequently and distinctly marked in the valleys of the lake
district of Cumberland, radiating in all directions from Great Gabel
as a centre, or, as are already noticed by us regarding the West of
Scotland (Arts. 10-13), goes so far against the glacial theory as appli-
cable to Arran, and in favour of the idea that the mounds and
terraces in question were formed when currents swept these glens,
during the gradual elevation of the land. That such elevation
may have been a long continued process we have already seen
reason to suppose (Art. 52, 53); and the effect must have been
a general disturbance in the sea bed, which, joined to the action
of tides produced then as now, could not fail to give rise to
currents of considerable force. Where these met the sea towards
the mouths of the glens, banks and terraces may have been thrown
up ; or a sudden elevation of the land of a cataclysmal character
may have given origin to long continued currents of sufficient force
to transport large blocks, and to throw down a promiscuous de-
posit, such as we find in the mounds and terraces of the mountain
glens. Such sudden elevations of a range or group of mountains
are still regarded by many geologists as the true explanation of the
" diluvial phenomena ;" and it was such probably that Dr. MacCulloch
had in view when he spoke, in the passage above quoted, " of other
causes, of a transient and probably of a diluvian nature," as giving
origin to the remarkable accumulations at the mouths of the Catacol
and lorsa.

59. The dispersed blocks present phenomena still more curious
and of much more difficult explanation. They are almost exclusively

88

granite, a very few only of slate being found. They are scattered in
great numbers over every part of the island, and are often of enor-
mous magnitude. They are most abundant and largest in the
vicinity of the granite nucleus, as about Corrie and the shore at
Corrygills ; and generally less numerous, and of smaller bulk, in the
remote southern districts. Occasionally, however, some very large
ones occur even there. They are limited to no particular locality,
but occur alike in the valleys, on the summits and northern
and southern slopes of the hills, in situations to which they must
have passed across deep and narrow glens. They are found also iso-
lated on the Holy Isle, which is separated from the mainland by a
wide bay, and two deep navigable channels. Blocks of the coarse-
grained variety are much more numerous than those of the fine.
The latter, indeed, are in a great measure limited to the tracts on
which Glen lorsa, the principal seat of this variety, opens towards
the south ; and this fact, in connection with the more sparing distri-
bution of the blocks along the northern coast, on which but one
glen with a narrow opening debouches, than in other parts of the
island, shows that, though the dispersion has been quaquaversal,
it has been to a large extent determined by the direction of the
valleys. Dr. MacCulloch, who has noted the leading facts regarding
the dispersion of the granite blocks with great accuracy, though
imperfect in many of his details, closes his account with the following
observations : — " None of the blocks have the marks of a distant
origin ; all have the characters of the granites of the adjoining moun-
tains, characters sufficiently distinct from those of almost all the

granites of Scotland No situation, perhaps, has

been pointed out where the origin of the travelled blocks is more
obvious, or their new position more difficult to comprehend, without
assuming considerable revolutions of the surface of the land over

which they have passed The compact and

solitary position of the fixed mass of granite, the identity of the
materials of this mass with that of the travelled stones, the gradual
diminution of these as they recede from the parent rock, and the
insulated position of the whole, render their origin indubitable, and
present to the geologist a spot, on the changes of which he may
speculate, with the certainty that he has before him a set of incon-
trovertible data from which to reason." — (Ut sup., p. 341.)

This passage places in a clear light the conditions of the problem,
and the difficulties attending it. The author does not, however,
propose a solution of the difficulties, nor does he enter into any theo-
retical discussion. His account of the travelled blocks is the only

89

one which we have seen ; no other writer on Arran, that we know of,
has turned his attention to the subject. It is hoped, therefore, that
the notices now given will be the more acceptable.

In Arran, as generally in other districts, the boulders belong to a
particular period. The entire system of rocky strata had been
formed, and the existing inequalities of the surface established ; but
in all probability the last upward movement of the land, to which
we have already often referred, had not taken place. The relative
age, in fact, seems to have coincided with that of the boulder clay of
Scotland, or with the newer pleiocene era. Then, as regards the
forces concerned, we know only two natural agents capable of
producing the effects. These are currents of water and moving
masses of ice. Now, the former are totally inadequate to carry for-
ward masses of the enormous magnitude found here, or even to
transport the lesser blocks over all the obstacles which they have
surmounted, in their outward course from the parent rock. Besides,
they are often found " perched" in situations where it is extremely
improbable that currents could have left them, and also crowded to-
gether in groups in places quite open, and removed from the influence
of eddies. It is true, indeed, that the origin of such currents can be
readily accounted for, by movements which we know to have taken
place — the elevation, namely, of the mountain nucleus from beneath
the sea. We have only to suppose that it was sudden and of con-
siderable amount, and we have at once generated a series of mighty
pulses, which would carry the disturbed waters, with their load of
torn off materials, along the surface of the lower lands, still sub-
merged. Rocky materials may thus have been swept away, and
re-arranged in new situations, valleys scooped out, and extensive denu-
dations effected. But the forces thus brought into play cannot have
been adequate to bear along the enormous masses, now far separated
from the parent rock ; and therefore we do not hesitate, on this and
the other grounds above stated, to conclude that moving masses of
ice were the transporting agents. In the passage of glacier ice adown
the valleys, and the buoyancy of floating bergs, forces of sufficient
energy would be lodged to carry the largest masses ; and this agency
we know, as already pointed out (Art. 11), is adequate to produce
the various phenomena of transport, grouping, and " perched blocks."

60. We must conclude, then, that the northern mountains formed a
mass of ice-covered land, with glaciers in the valleys reaching the
bold shores of the sea of that period. From the extremities of these,
rock-bearing masses of ice, of which at least a few must have been
considerable bergs, floated away, and stranding or melting, threw

H

90

down their load of blocks. Thus the shores of the island, and the
southern plateau as yet under water, became encumbered with vast
multitudes of granite boulders, chiefly of that coarse-grained variety
constituting the highest mountains. The land, previously moulded
into its existing outlines by submarine currents, was next perma-
nently raised to that altitude which it retained .for a vast period —
certainly much more than 2,000 years (Art. 5) — till that final
upward movement occurred which is marked by the present inland
cliff.

Such is, we think, the only view which the phenomena admit of.
Beset with formidable difficulties as regards every region, there are
in Arran others of a special kind. As already remarked in the
passage quoted from Dr. MacCulloch, the phenomena of Arran must
be considered in their isolated aspect, and independent of the main-
land. In the Grampians we have ample room in wide open surfaces
for the support of snow-fields to serve as feeders of the glaciers (Art.
11). In Arran such spaces are limited to narrow and greatly in-
clined tracts at the bases of the higher central peaks, and above the
cols between the glens, containing^an area which seems too small for
the support of such a snow-field. \ Yet) we do not see what other
hypothesis can be framed. The existing levels of the surface forbid
us to suppose that the whole island, elevated as now, in both divi-
sions alike, high above the waters, was wrapped in sheets of ice,
across which the granite boulders, as they dropped from the high
peaks, were carried onwards in all directions on a slowly descending
viscous mass. A continual descent is required to effect such a trans-
port ; and this could not exist beyond the limits of the mountain
nucleus ; the boulders could not thus have passed to the heights of
the southern plateau. This portion, therefore, we are constrained to
admit, must have been wholly and deeply depressed below the level
of the mountain tract of the north, on which the glaciers rested ;
subsequent elevations, marking probably the close of the drift period,
established between the two portions of the island those relative
levels which still subsist. But the present level of the shores was
not yet attained, nor the actual coast outlines as yet carved from
the rocky border which broke steeply down all round the island.
The sea covered the plains of Brodick and Shiskin, and stretched its
winding arms far up the solitary glens. During the slow progress
of perhaps forty centuries, the streams from the rugged mountain
sides and gentler hill-slopes bore down detritus of granite-sand,
slate, and quartz pebbles, and spread them out below the waters of
the quiet friths. In sheltered places the tides and waves cut a low

91

but well marked margin along the highest water line ; while on the
open shores the heavier surge wore deeper, the hill-slopes were cut
into a steeper and higher cliff, and hollowed out into caves in all the
rocks alike. The testacea and other denizens of the present shores
already inhabited the waters of that remote period ; but we have no
evidence that man had yet appeared. It is most probable, indeed,
that the last elevation of the land, to which we have already often
alluded, took place before the human period. We are only certain,
however, that all the existing levels were established prior to the
Roman invasion. Here, as generally in the west of Scotland, this
last elevation amounted to twenty or thirty feet, and gave to Arran
its present maritime border, and the inland cliff which forms a sin-
gularly picturesque feature in its coast scenery.

92

EXCURSIONS IN ARRAN.

EXCUKSION I.
To THE SUMMIT OF CIOR-MHOH.

61. THIS shall be our first Excursion. It will reveal to us the
structure of the granite nucleus, and th^e relations of the mountain
groups. It will show us the basset edgW of all the strata as we
pass in succession across them to the central ,granite. We shall see
some curious dikes, explore a lonely corrie, (Airnb a high pass, and
thread a difficult pathway by the edges of the highest cols. The
morning clouds have melted from the peaks; there is neither bank
of mist nor cirrous haze to veil the far-off horizon ; the day will be
calm and bright, and the view from the summit glorious. Cior-Mhor
(Kior-Vawr) is that far-off peak, with sharp point and rugged shoul-
ders, rising behind the plateau on the south-west of Goatfell. We
shall reach it by a walk longer and more difficult than the ascent of
Goatfell, and the more exciting that it is somewhat dangerous.
Should a mist happen to surprise the tourist upon certain portions
of the route, his situation might be very critical. How promising
soever the day may be, let him never enter these mountains without
a pocket compass. The mists come down so sudden and so thick in
this changeful climate that without it he will be bewildered and lost
amid the high cols and peaks, and huge slippery granite sheets.
With ordinary caution, and the use of a correct compass, he has
nothing to fear. True, he will find neither house nor herd's shiel-
ing within the mountain circuit ; but directing his steps by the
compass, he cannot fail, in a walk of two or three hours at the
utmost, to reach the inhabited border, where a frank welcome will
meet him at every cottage door. Let it be remembered, however,
that the variation of the magnetic needle in the west of Scotland
is now about 24° west of true north. To the geologist we would
recommend to carry, besides his hammer, indispensable at every
step, a good clinometer with which to note the varying dips and

93

inclinations of the slate and sandstone, and the relations of these to
the granite centre and the numerous dikes. — On this and most of
our Excursions our departure will be taken from the shores of Brodick
bay, the unrivalled grandeur and beauty of which attract the greatest
number of summer visitants. For a few days' sojourn new induce-
ments are now afforded by a fine spacious hotel on a beautiful site at
Invercloy, on the south side of the bay. Here and at several other
points on the east coast steamers call six times in the day during the
summer months.

62. The rock on the shore at Invercloy is a conglomerate of
the age of the coal — a member, in fact, of the coal formation.
Murchison, Sedgwick, and Ramsay have classed it as a lower member
of the new red ; but, as already stated (Art. 48), on evidence which
we think inconclusive. The inland cliff marking the old coast line
is well seen on the Invercloy shore, and extends far up both sides of
Glencloy. The lower part of the glen, much of the plain of Brodick,
and the marshy grounds at the head of the bay, are but an expansion
of the terrace which formed the sea bottom, when the tides and
waves were carving out the cliff. The alluvium and rolled stones
form, however, but a thin covering to the subjacent sandstone, which
appears in the river bed a little way up the glen. On the north-west
the sandstone is quarried upon the line of cliff, and forms a tolerable
building stone. The dip is nearly south, at about 25°. By the side
of Brodick wood, adjoining the handsome new school house lately
erected by the Duke of Hamilton, a vein of pitchstone occurs in the
sandstone. The contact is not seen at either surface, so that the
thickness cannot be ascertained ; a portion only of the front appears
by the side of a lane, showing a prismatic structure in the rock, and
an underlie in the vein towards the west. In large blocks lying
loose upon the surface in the course of the vein, which here seems
stript of the sandstone through a considerable breadth, a similar
structure is seen. The colour is bottle-green, and specks of red
felspar disseminated in the base give the rock a porphyritic texture,
approaching that of pitchstone porphyry. The direction is nearly
south-east and north-west ; but the vein cannot be traced either way
beyond the limited portion here exhibited. It is probably a con-
tinuation of one of the many beds or veins of the Corrygills shore,
which we shall notice in another Excursion. A dike of disintegrating
ironshot greenstone, forming a bank behind the school house, has
an angular course with respect to the vein ; but the nature of the
ground does not permit their connection to be observed. In the
opposite direction the dike intersects the inclined strata of sandstone,

94

but no marked change is produced. It is in excellent taste that the
striking geological features of this spot have been left untouched in
carrying out the improvements connected with the erection of the
school house.

By the wayside here, where a sweep of the road gradually opens
to us one of the finest vie^s in Arran, there stands a huge upright
stone, marking, perhaps, (the s^o^Nwhere a chief was interred, or
where a leader fell in the^oM days of feud and warfare ; or may-
hap the scene of some decisive battle with the old Norse invaders.
Many such stones are found in the island, but their purpose and date
of erection are wholly matters of conjecture. There are several in
this immediate neighbourhood ; on the high ground south of Inver-
cloy, and on the plain of Glenshant, between the mouth of Glen Rosa
and the site of the old village of Brodick. A complete circle of such
stones formerly existed at the mouth of Glenshirag; it is briefly
noticed in Mr. Headrick's book; but not a vestige now remains;
in 1813 the stones were broken up and removed, to make way
for the operations of the plough. In 1836 a farmer, not less
gothic in his ideas, removed a double circle of such stones from the
farm of South Sannox, and used the materials in the erection of a
stone fence. A single pillar still remains in front of South Sannox
house. In most places where we examined these stones, we found
them to be coarse sandstone of the old red formation. As this does
not exist in many of the localities where the stones now stand, we
must conclude that mechanical appliances of great power were brought
to bear in their transport ; and therefore it is not wonderful that, in
a rude age, their erection was ascribed to the hands of giants. In
all ages the illiterate observe facts and phenomena with tolerable
accuracy ; but their explanations always introduce the marvellous or
the supernatural. The subject will be again referred to in our
notice of Tormore.

63. There are two paths to the entrance of Glen Rosa ; we take
that which passes Brodick chapel, and crosses the opening of Glen-

95

shirag. The chapel stands on a platform, bounded northwards by a
low cliff of sandstone, and overlooking one of the most varied and
pleasing views in Arran. In this sandstone, underneath the north
wall of the chapel enclosure, there is a bed of carboniferous limestone
in a vertical position. It has been largely quarried, and a small
portion only is now visible. It contains fossils, of which the most
characteristic is the producta gigantea, completely identifying this
bed with the limestones of Corrie, the Salt Pans, Bein Lyster glen,
&c., and enabling us, therefore, to assign the sandstone also, without
hesitation, to the age of the coal formation. A little farther on,
above a rustic bridge, where the Shirag burn, rushing out from a
winding rocky gorge overhung with trees, forms a scene strikingly
picturesque, another bed of limestone occurs in the sandstone. Thence
to the entrance of Glen Rosa, we pass across the lower beds of the
carboniferous formation, which, however, are nowhere seen except in
spots in the bed of the Rosa burn. The succession of the strata is
shown in the annexed cut.

el,

(a a) Sandstone and conglomerate ; (6) producta limestone ; (c) old red sandstone ;
(d~) schist ; (e) granite.

We now reach the outer edge of the band of old red sandstone,
which, ranging from the Corrie shore diagonally by the flank of
Goatfell, crosses the opening of the glen. It is seen on rocky pro-
minences by the side of the path, but no junction is visible. The
beds here exposed consist of a dark-coloured, close-grained sandstone,
with specks of mica, bits of quartz, and small clay -galls, and are very
characteristic of the upper portions of the formation. The lower
portions are seen farther up the glen, but at some height on either
side, in the wood and moor on the left, and the hill-side on the right.
They are very coarsely conglomerate. Specimens of both varieties
may be seen in the stone fence by the side of the wood.

The alluvial mound at the entrance of the glen has been noticed
already, as most probably the terminal moraine of a glacier which
once filled the valley. It is precisely in the position where such
a moraine would have been thrown down, and consists of such
materials as the ice would have borne forward ; and its height, fully
thirty feet from the bottom of the glen, places it far above any
existing river action. Not knowing its height above the sea level,
we are unable to say whether its accumulation may not have been

96

due to combined sea and river action before the last elevation of the
land took place. It seems to us, however, to be higher than any
level the waters could then have reached. It appears to have ex-
tended, at some former period, entirely across the opening of the
valley, backing against the hill side on the south, as it now does in
the opposite direction, and forming the barrier which confined a lake,
occupying at that period the lower portion of the glen. The burst-
ing of such barriers, and their subsequent modification by floods in
the river, are common phenomena in mountainous districts. Traces
of a lateral moraine are seen on both sides ; and farther up the glen,
where it turns northwards, two other mounds, rising high above the
stream, are in the position where a terminal moraine would be thrown
down, after the ice had retreated from the lower part of the valley.

The discovery of an ancho^ inJGlenN^osa, similar to those now
used by the herring smacks which visit Brodick bay, has often been
referred to as proving that, since the island was inhabited by a
people far advanced in civilization, the sea filled the valley, and
afforded a " trustworthy station for ships." That an anchor was
really found, brought to the smithy at Invercloy, and worked up
into various articles, we think there cannot be a doubt, from the
accounts given by several persons still living, who saw it and handled
it. All agree, however, in fixing the locality in which it was found
at a place where peat is cut, at a considerable height on the
southern hill side, and therefore far above the level at which the
waters of the sea stood before that last elevation of the land to
which we have so often alluded already. If the discovery, then, be
admitted as a fact by the archaeologist, it is entirely without that
geological significancy which attaches to the Clyde canoes. With
the archaeologist the explanation may be left.

64. The contact of the lower old conglomerate with the clav slate
is not seen in Glen Rosa. The latter rock first appears in the bed
of the stream, at the sharp turn where it begins to flow eastwards ;
but the junction must be farther down the burn. The slate rises
high into the hills on both sides, forming on the north the principal
mass of Glenshant rock, called also the Pillar, from a large isolated
sheet or prism, standing out detached from the front of the bold cliff.
The precipice is about 1,000 feet above the river, and forms one of
the finest features of this noble glen.

We now approach the base of the series, where the central granite
rises from beneath the enveloping slate rocks ; and here a celebrated
junction occurs in the bed of the stream. The hill sides show the
contrast of the two rocks from a great distance, in the bare stony

97

character and loose gray blocks on one part, and the grassy or
heath-covered slopes, with dark terraced ledges, on the other ; and
the geologist is therefore prepared to find a junction somewhere here
in such a natural section as the river affords. It occurs about
two or three dozen yards below the point where the Rosa burn
receives from the west side its only tributary — the Garbh-Alt
or Kough burn, which drains the whole eastern side of the Ben-
G-hnuis range, and comes down into the glen, bounding headlong
across the huge granite sheets in a series of striking falls. The
junction has not been so well shown these few years (1855-58)
as it was formerly, in consequence of the accumulation of loose masses
of granite ; still it is sufficiently well seen to make the place interest-
ing and instructive in a high degree, and some future floods in the
river may again open it better up. The slate is greatly altered for a
considerable distance down the stream, and pervaded by small veins
and strings of quartz, and granite in which quartz predominates.
The colour of the slate is changed, having more of blue than is usual
to it ; the structure is altered also, the laminae are contorted and
present thin bands of different colours, chiefly blue and gray ;
the latter being purely siliceous, that is, flinty slate or quartzite with-
out the colouring matter, iron or manganese, which exists in the
former. The slate on this side of the mountains is generally a dark-
coloured coarse siliceous rock, showing shining crystalline flakes in
fresh fractures; in some places assuming that arenaceous semi-con-
glomerate structure which used to be designated as greywacke. Both
structures are obliterated on approaching the granite ; the colour is
bluish, or blue and gray in alternate bands, the structure is extremely
fine-grained, and the hardness and toughness are both excessive.
These changes, the contortion of the laminae, or the total disappear-
ance of all stratification, coupled with other modifications not seen
here, but to be again noticed, clearly indicate that the schist to a
considerable distance from the granite was subjected to intense heat,
and remained in such a state of at least semi-fusion as to permit,
under the action of chemical forces, a new arrangement of parts, and
the permeation and interlacing of veins from the molten rock below.
The granite veins are less numerous, smaller, and of varieties differ-
ing from the ordinary type of this rock more than is usual in most
other junctions with the slate ; such might perhaps be seen in the
interval of several yards here obscured before the granite itself is
reached. The great extent of the altered slate seems to indicate
that the strata near the junction are of inconsiderable thickness, and
that the granite exists beneath at a small depth, as shown in the

o

98

illustrative cut at e. The slate is here traversed by a basaltic dike,
still further modifying its altered structure. The dike intersects the
bed of the stream at a small angle, but is seen only on the east bank ;
it ranges about magnetic north and south, and has a breadth of ten
or fifteen feet. We shall meet with it farther up the glen on
another Excursion. Rising from the bed of the stream in great
rhomboidal masses, divided by partings here inclined towards the
slate, the granite extends in a slanting direction up the hill towards
Goatfell, and on the opposite side by the Garbh-Alt burn, so that
the line of junction almost coincides with the southern margin of the
stream. The remaining part of our walk is entirely on the granite.

65. Our path now lies up the steep slope forming the western side
of the glen, a little to the north of the Grarbh-Alt, which we keep
on our left hand. Having reached the summit level we are on the
southern slope of the high rugged ridge called Ben-Talshan, which
forms the western boundary of Glen Rosa. In the hollow between
it and the lower swells of the Ben-Ghnuis range, the Garbh-Alt
pursues its rapid course from north to south, along a granite bed,
down a pretty fall, and then between perpendicular walls of granite
about twelve feet in height, till, escaping from this rocky barrier, it
sweeps round the south, end of the ridge, and plunges headlong into
the depths of Glen Rosa. The gorge has been excavated along the
line of a basaltic dike, which occupies the bottom of the stream
throughout, and retires from it at the base of the fall. These dikes,
as already remarked (Art. 40), are prismatic across; and this struc-
ture renders their disintegration much more easy than that of the
granite. The amount of wearing in this case is measured by the
depth of the chasm, and the distance to which the fall has receded.
The stream ran at first on the level of the top of the granite walls,
and the fall must have been at the southern extremity of the chasm ;
the recession would cease, or become extremely slow, when the
present situation of the fall was reached, as the dike here retires
from the stream. The dike is ten to fifteen feet wide,' and ranges nearly
due north and south. The rocks adhere firmly at the junction, but
the alteration on the granite is not remarkable. Similar cases of
the excavation of river channels along the line of dikes are frequent
in Arran. As a general rule, fractures or faults determine the course
of streams in the first instance ; along such lines the excavation is
much more rapidly effected.

The steep brow on the eastern side of the wide hollow where we
now are, exhibits many rounded masses of granite, presenting the
" moutonneV' character of surface, as if moulded by the action of

99

ice : but as no striae were observed, we can hardly ascribe them to
the action of glaciers, as the forms may be due to the effects of dis-
integration on the concentric structure upon the large scale, so often
seen in granite. The bed of the stream, as we pass up, is strewed
with many loose rounded masses of pitchstone and trap, indicating
the existence of dikes or beds of these rocks among the lofty precipices
on the west. Mounting this steep brow, to reach the corrie under the
north front of Ben-Grhnuis, we meet with a dike of spheroidal trap in
the bed of one of the streams ; it is about seven feet wide, and
ranges 35° W. of N. The rounded masses of granite here may
have received their forms from the long continued action of water
trickling over them, and torrents occasionally sweeping along gravel
and large stones. Arrived at this corrie, we are in the midst of a
scene wild, lonely, and picturesque. The bare and rugged precipices
of Ben-Grhnuis rise high into middle air on the south, with their
immense sheets and rhombic masses of granite, from six to twelve
feet in the side, piled up, block on block, in massive courses, like the
huge rough masonry of giants. The topmost row, broken by clefts
and deep gashes, due to irregular disintegration, shows grandly in its
perfect definition against the clear sky. Along the front, which
sweeps round to form one side of the corrie, there stand out here and
there enormous pillars of the rock, detached from the cliff behind,
resting on a basis which is rapidly giving way under the active
agents of waste in this changeful climate, and threatening a speedy
descent into the valley of the Grarbh-Alt. The rugged outlines of
the Groatfell group bound our view on the east, the distant landscape
being shut out by the intervening ridges ; and the eye from this
point does not take in a single human dwelling, or other sign of the
abode of man. No sound reaches the ear but that of the crystal
rills trickling from the clefts of the granite, the hum of insects on
the wing, or the twitter of the solitary stone-chat, as it flits from
rock to rock. The solitude is complete, the silence solemn and
impressive. Our perfect isolation amid such a scene, — the vast
dimensions of the objects around us, and their expression of power,
are true elements of the sublime, and awaken the most pleasing and
elevating emotions. There is a delightful consciousness of a new
activity in the fancy, and an increased buoyancy and intensity in
the feelings. To the geologist there is another source of the sub-
lime in contemplating the effects of the mighty forces which have
rent the crust of the earth, raised these mountain masses from the
fiery depths beneath, and scooped the glens and comes out of the
solid rock.

100

66. The cliff on the north side of the corrie shows some interest-
ing dikes. One of these is of green pitchstone, and cuts the granite
sheer through in a N. and S. direction from bottom to top of the cliff.
It is four feet wide, prismatic across, and owing to the more rapid
disintegration, depressed below the level of the granite. The con-
tact does not present any peculiar change in either rock, such as
invariably marks the planes of contact of pitchstone and the sedi-
mentary strata. The pitchstone is decomposed into a thin white
film in many places along the outer edge of the dike, next the
granite, in consequence, probably, of the oxidation and removal of
the iron which enters into its composition. The dike is in some
parts of its course obscured by debris, but upon the whole is, per-
haps, the best defined dike of this rock occurring anywhere in the
granite of Arran. But phenomena of much greater interest will be
again noticed in connection with other pitchstones.

Two basaltic dikes occur close together, about 100 yards east of
the dike we have been describing ; they traverse the granite preci-
pice in the same manner, but in a different direction, their course
being about 28° W. of N., subject, however, to undulations. These
dikes are from 18 inches to 2 feet broad, and are separated by a
granite band 8 or 10 feet in breadth ; elliptic masses of granite, of
which the largest we observed was about 18 inches by 9, are enclosed
in the trap, but very little altered. The alteration, indeed, is no-
where remarkable, the granite being in some places coarse, in others
fine-grained, along the planes of contact. Specimens may be ob-
tained of both rocks firmly adhering.

Some pretty plants occur here in shady spots on the granite
ledges, where a little soil has accumulated ; they will reward the
young botanist for his long walk to their secluded habitat. The
Sedum rkodiola, Oxyria reniformis, Saxifraga stellaris, Alchemilla
alpina, and several others, rejoice in the temperature and humidity
which these heights supply.

To reach the head of the valley, and the first ascent of the Pass
into Glen lorsa, we now direct our steps along the base of the pre-
cipice, where the grassy tufts and granite debris afford a safe footing
on the steep slope, keeping as high a level as possible, in order to
shorten the ascent by which the summit is reached. As we pass
along we notice several dikes of pitchstone and basalt, ranging
north-westwards up the precipices on our left towards the summit of
the ridge, and doubtless crossing down on the other side into Glen
lorsa ; but we may not now delay to trace them. The Ben-Talshan
ridge on our right, and that along which we have passed, coalesce at

10 L

the head of the valley, and their union is marked by a very steep
grassy slope, encumbered with granite blocks projecting from the
soil in situ, or deeply imbedded in it, but free from the huge flat
and smooth sheets along which it is difficult and dangerous to cross.
This depression or break is in the direction of the head of the valley,
and owes its origin to a basaltic dike, which appears at the beginning
of the ascent, and is seen to enclose masses of granite as in the case
already mentioned. Its range is magnetic north and south, and width
about twelve feet. The situation of the Pass to which we are now
to mount, and which is fully 1,000 feet above us, is indicated by a
bold rocky point, a little in advance of Beilach-an-id-bho, the last
high summit of the Ben-Ghnuis range. Marking its position by
the compass, and then pressing up the steep, we gain a wide and
grand prospect from the summit of the Pass. Clambering to the
top of the rocky point, we look down from a height of fully 2,000
feet into a nook or recess of Glen Eosa on one side, and into Glen
lorsa on the other. The descent towards the latter is easy ; towards
the former, it should not be attempted; for, if practicable, it is
highly dangerous. From the Garbh-Alt valley, in fact, the only
access to Glen Rosa is by the way we have come up.

67. We are now at the southern extremity of the Ceims (Kyims)
which link on Cior-Mhor to the Ben-Ghnuis range. This is the
ridge whose sharp and rugged outline, seen from the shores of
Brodick bay, is well known as bearing a striking resemblance to the
profile of a distinguished living statesman and writer. The ridge
is formed by the edges of vast tabular masses or sheets of granite,
inclined towards Glen lorsa at a considerable angle, and cut sharply
down on the side next Glen Eosa, so as to present towards it a con-
tinued precipice, formed of successive tiers of granite sheets and
rhombic blocks. The jagged outline is due in part to the irregular
wearing of the coarse-grained granite, but still more to the intersec-
tion of the ridge by a series of whin dikes. The horizontally pris-
matic structure of these subjects them to a more rapid decay than
even the friable coarse granite ; and hence most of the deep notches
of this jagged ridge mark the situations of whin dikes. The fact is
curious and interesting, and has not been before noticed. Eanging
up the front of the precipice from Glen Eosa these dikes cut right
through the crest of the ridge, and pass downwards into the fine-
grained granite, which occupies most of the lorsa valley, and rises
up on the back of the Ben-Ghnuis range and the Ceims, as far as the
level of many of the cols, that is, the lowest parts of the ridges be-
tween the glens. Here, then, we have a decided case of a system of

102

dikes common to both granites, and newer than either of them ; and
a confirmation of the view already stated (Art. 46), that trap, and
not the fine-grained granite, is the newest rock in the island. It
seems highly probable, from the direction in which these and the
other dikes already mentioned range, that they are the same as
those which were found crossing the fine-grained granite tract on
the west side of the lorsa valley (Art. 46, p. 68).

68. The jagged and notched character of the ridge makes it im-
possible for us to pass along it on our way to Cior-Mhor ; neither can
we safely cross the huge granite slabs at the back of the ridge, as
they are smooth, slippery, and considerably inclined. But below
these a safe, though rough and irregular pathway, will be found ;
and from this we can occasionally pass upwards towards the ridge,
along the clefts in which the dikes lie, to have a peep down into
Glen Rosa, or to scan the frowning cliffs on the north side of Ben-
Talshan. For the latter purpose a telescope will be useful. We
must be careful, however, to return by the cleft by which we came
up, till we reach the path. The granite sheets must not be attempted,
as a single false step upon them might hurl the tourist with fearful
velocity into the valley at their base, filled with blocks and debris.
The range, width, and structure of the dikes are well seen as we
pass along ; the width is various, in some 5 or 6 feet only, in others
10 to 12, and 15 to 18 feet. The broadest, being of this latter
width, is one on the south side of the col, between Glen Eosa and
Glen lorsa. It consists of a crumbling greenstone, and ranges
29° W. of N. The others have various ranges between W.
and N. Many small shining flakes of crystalline oxide of iron occur
in the trap of these dikes. The ridge of the Ceims is composed of
the coarse-grained granite ; but the path at its west base, along
which we have come, is partly on the fine-grained variety. This
appears generally at the height of about 1,600 feet on the cols, and
on the west side of the ridge, but is not seen in Glen Eosa nor on
Goatfell. It disappears on the ascent of Cior-Mhor, and is suc-
ceeded by the coarse-grained variety. The contrast is remark-
able. The rock has quite a different aspect, a different feel under
the hammer, and a peculiar style of disintegration, giving smooth
outlines, and an entire absence of the aiguille-like highly pic-
turesque forms, into which the coarse variety is resolved by the
action of the atmosphere. The decomposition of both rocks conceals
the contact, and we were not so fortunate as to discover anywhere
the actual junction of the two varieties. — But the day is waning,
and we have yet to scale the lofty peak of Cior-Mhor, shooting

103

grandly up 900 feet above the ridge on which we stand. Though
right to the summit "we might press, and not a sigh our toil
confess," we must pause now and again to mark the ever-changing
features of the magnificent scene gradually opening towards the
west and north, and the . new aspects in which the rugged crest of
the Ben-Grhnuis range now appears. We must note, too, the change
in the rocky floor over which we are passing. We leave the fine-
grained granite on gaining the foot of the steep ascent : thence to
the summit the mountain is composed wholly of the coarser kind.
It is disposed in irregular tabular masses, split up into rhombic or
cuboidal forms by fissures, independent of disintegration, and coeval
with the solidification of the rock. The thinner masses we have
called sheets ; in both the divisional planes separating mass from
mass, and the fissures perpendicular to them, are alike the result of
crystallization on the large scale, and bear no analogy to stratifica-
tion, which is the result of sedimentary deposit. The disintegration
of granite, porphyry, and other igneous rocks, is mainly determined
by these lines of separation ; in some granites, but more remarkably
in porphyry and trap rocks, by the concretionary structure, already
referred to in the case of the latter (Art. 31) ; and which has
resulted from the mode in which the crystalline centres of affinity
develop themselves at the first parting of the heat of fusion, in a
melted mass beginning to solidify. The schistose and prismatic
forms, under which granite often appears, are but slight modifica-
tions of the forms already noticed, depending on the relative position
of the divisional planes. The schistose form has often been de-
scribed as a true stratification ; but this structure is not continuous
in one direction as strata are, nor does it exhibit the fracture or incur-
vation of beds ; it is in truth but a local modification of the rhombic
or cuboid form, under which granite more frequently appears.

69. The summit of Cior-Mhor, narrowed by distance into the
form of an alpine aiguille, we found to be an irregular elongated
plateau, large enough to accommodate a small pic-nic party. The
rugged shoulders flanking the peak are huge rifted masses of bare
rock, separated by clefts which descend far into the heart of the
mountain. On three sides are inaccessible precipices ; the ascent is
possible from the west side only. Thrown forward on a salient
angle of the western ridge, and little more than 300 feet lower than
Goatfell, Cior-Mhor affords a commanding view of the ridges and
dividing valleys, the peaks and precipices of this singular mountain
group. Its situation as the geographical centre of the tract has
been noticed already, and the relations of the various ridges pointed

104

out (Art. 43). Viewed from the summit where we now stand, the
scene is very wild and grand. The ridges swell up steeply and
nobly in front of us, from the very depths of the glens, in their
majestic forms of "peril and pride," and stretch away on either
hand, shooting up here and there into the highest peaks, and cut,
in lower parts between, into spiry fantastic crests. The craggy pre-
cipices and long steep fronts of naked rock have an imposing
expression of sternness and power. Crowning the ridge of which they
form the lateral supports, Goatfell presents on this side its grandest
aspect. The eye, from its elevation, takes in under a large visual
angle the entire western steep from the summit of the mountain to
the bottom of the glens. On the north side of Glen Sannox the
ridge of the Castles and Suithi-Fergus starts up with little less of
suddenness and grandeur. Lying deep down at the foot of these
lofty ridges, and closed in on the south-west by the high mountain
on which we stand, Glen Sannox has an air of singular loneliness
and solemnity. The same breadth of form and grand scale of parts
are found nowhere else in Arran ; — the very simplicit}'- of the com-
position is one of the greatest charms of the glen. The silver
thread of its river, meandering far out eastwards, leads to the world
of life without ; arid the gentle murmur of waters, stealing up from
its sombre depths, breaks pleasingly the awful stillness of the
summer day on these high peaks.

We have attempted in preceding paragraphs (pp. 69, 76, 77), to
indicate the successive steps of the process by which the mountain
nucleus acquired its actual conformation. From our present com-
manding position we are better able to estimate the amount cf
elevatory force required to raise the high peaks and massive ridges
around, and the length of time and intensity of erosive agents which
the formation of the long and deep chasm dividing the ranges
demands. Fill up this chasm and -the other glens with solid granite
masses, to the level of the peaks and ridges, over all throw a mantle
of slate, continuous with the present circular boundary around the
nucleus, depress the area full three thousand feet below the waters of
the ocean, and some measure will be obtained both of the force and
the time through which the present aspects were assumed.

The sunbeam is the joy of this mountain wilderness. It lights
up the solemn old rocks till they laugh into beauty under its bright
spell. Though devoid of vegetation which might throw bright
tints around the rugged surfaces — for the saxifrage and alchemilla,
the cryptogram ma and other ferns, the club moss and juniper,
nestle in shady clefts, and small patches of grass occur only here

105

and there among the blocks — yet are not these bare rocky masses
without a certain natural adaptation to produce warm harmonious
colouring. The three ingredients of granite have peculiar shades
and different reflective powers; oxide of iron, always present as a
constituent, passes in decomposing through various rich tints, and
the rocky surfaces themselves, smooth or rough, dry or moist, are
often dotted with small lichens. The result is a sober but pleasing
tint in keeping with the general expression of the mountain scenery;
it runs through various shades of gray, purple, and a tempered red
or orange. The effects seen from Cior-Mhor are finest in the after-
noon. Marvellous contrasts now lie athwart the stony ridges and
deep glens, adding a wondrous charm to the scenery* The sun has
gone down an hour since in the depths of Glen Rosa, and a deep
gloom has settled on the dark recesses of Glen Sannox. Sharp
shadows of the western ridge, showing a perfect profile of its jagged
crest, are slowly creeping up the western front of Goatfell, whose
summit is bathed in a glorious flood of orange light. Thrown back
from rock to rock in mellowed and harmonious tints, it maintains a
bright twilight along the base of the western ridge, by which we
must descend, and throughout the upper part of Glen Eosa, along
which our after path will lie. Taking a last survey of the sur-
rounding peaks in their gorgeous evening tints, and contrasting the
bold rocky foregrounds, now flooded with light, with the smoother
and fading outlines of the lower hills, we must hasten downwards*
The far off landscape we shall see better another day from the
summit of Goatfell.

The low ridge or col connecting the base of Cior-Mhor with the
next height to the south, breaks down steeply, but .without pre-
cipices, towards Glen Eosa. We can descend easily at almost any
part of it. A few minutes will bring us to the junction of the two
burns, over the most rough and toilsome part of the long walk yet
before us. Farther our way lies nearly by the side of the Eosa
burn, through the moss and heather, till we reach the Garbh-Alt,
where our ascent began in the morning. The smooth carpet of the
glen is now beneath our feet, and we dismiss all fears of adders in
the path, which troubled us a little in the uncertain light of the last
hour. Emerging from the glen, and crossing the pretty burn by
the rustic bridge, we gain the Brodick side and Glenshant lane. In
twenty minutes more we are at the door of our comfortable inn,
and are soon seated at the welcome evening meal. It is pleasant to
talk over the incidents of our long walk ; they will awaken joyful
memories on wintry nights, years to come.

p

100

EXCURSION II.

THE CORRIEGILLS SHORE.

70. TO-DAY we shall stroll leisurely by the sea-side, and study the
eruptive rocks which break through the Corriegills sandstone. The
botany of the shore is rich, and the pools in the tide-way teem with
marine life. We shall notice in this place the geological phenomena
only. A group of whin dikes marks the first emergence of rock from
beneath the Brodick sands; and from this point eastwards the rocky
platform exhibits a complete network of interlacing veins and beds
of igneous products, traversing the sandstone strata. Between the
end of the sandy beach and the landing-pier at Spring-bank there are
several cases of bifurcation of dikes, and of a singular crumpling of the
sandstone strata. The bed of the burn within the pretty grounds con-
nected with the hotel shows several greenstone dikes, and the beds
of sandstone are well seen in the banks and rocky ledges over which
the water tumbles. On the shore fine sandstone and conglomerate
are irregularly intermixed, indicating periods of sudden and gradual
deposit, and varying forces in the transporting currents. The sandy
strata are red, yellow, and white, and, as we advance eastwards, pre-
dominate over those of conglomerate structure. The fragments in
the conglomerate are mica slate, like that of Cantire, slate similar to
that of the nucleus, white quartz, and quartz of that peculiar
resinous variety (Art. 47), for which we know no locality in Arran or
elsewhere. Pieces of porphyry also occur, but no fragments of
granite. The whole series dips nearly south, at angles varying from
15° to 20°. The upper surface of the sandy beds is worn in a
singular way, portions more quartzose, or with a calcareous cement,
standing out in thin, sharp, irregular ridges, while the parts around
are worn away, being softer or more ironshot. The rock has thus
a honeycomb structure, like what one often sees in the worn coral-
lines of the mountain limestone. Numerous bowl-shaped cavities
also occur, due, probably, to the removal of imbedded quartz balls, or
the grinding action of these, by the movements of the waves, when
once loosened from their bed in the sandstone.

Some general remarks have been already made (Art. 57) on the
dikes of this coast, and we shall now only notice the individual cases
of most interest. The whole number is about sixty, and the direction
generally between N.W. and N.E., a few running nearly E. and W.

107

Most of them alter the strata of sandstone more or less. The
great majority are depressed below the level of the sandstone, owing
to the more rapid disintegration depending on their structure, as
already often noticed. They are of all widths, from eight inches to
forty feet, and the sides are generally parallel, and the course recti-
linear or slightly undulating. Most of them traverse quite across
the rocky platform, and are continued into the cliffs, up whose front
they are seen to range, either level with the surface, forming deep
gashes, or projecting like walls. These cliffs are the old sea margin,
and are hollowed into caves along their bases, and otherwise sea-worn
to a considerable height. The gashes in the cliffs were doubtless
formed when the sea stood higher ; the process being now completely
arrested in such situations. But dikes placed under circumstances
exactly alike do not waste with the same rapidity. Though the
prismatic structure is the same (Arts. 31, 40), the chemical compo-
sition varies, as does also the internal texture, while the adjoining
sandstone varies also in its capability to resist decay. When the
alteration produced by the dike is great, the sandstone will resist
disintegration ; if the contrary is the case, the sandstone may wear
rapidly, and the dike project. "From some experiments made
several years ago," says Mr. James Napier (paper quoted in Art.
57), " on the decay of trap boulders, I found that certain varieties
of that rock are rapidly changed by the action of water ; lime and
magnesia being dissolved out, the iron converted into a peroxide, and
a crust formed on their surface, which is brittle and easily abraded."
Mechanical and chemical differences have thus both to be considered,
as well as the relative powers of resistance of the dike and the con-
taining rock.

A remarkable group of dikes occurs under the east end of the high
cliffs, near the point where the shore bends southwards. One of
these is the broadest dike of greenstone on this coast. Its general
breadth is twenty-five feet, but it widens at one place to forty feet.
The sandstone is rendered very hard and quartzose to the distance
of several feet. The range is 47° W. of N., and the inclination east
at a small angle. A deep fissure marks the course of the dike up
the front of the cliff. This dike is noticed by Play fair, in his Illus-
trations of the Huttonian Theory ( Works, vol. i., Art. 266), as produc-
ing a marked change on the sandstone, and as indicating the relative
durability of the two rocks. A little east of this dike is another, nine
to twelve feet wide, inclined to the west, and ranging 18° E. of N. It
offers no remarkable appearances ; but the next dike east of it, though
but seven feet wide, alters the sandstone more than any other of the

108

whole series. This is probably owing to the nature of the rock,
which, being a highly crystalline greenstone, must have passed slowly
from a state of fusion. The stratification of the sandstone is
obliterated through a space of seven or eight feet, and this rock
assumes the structure of a claystone. The case is strongly in favour
of the view often advanced, that the Arran claystones are merely
metamorphic sandstones. Intersecting this dike is another, ten or
twelve feet wide, ranging 37° W. of N., dipping E.N.E., and
consisting of compact fine-grained greenstone. It is sunk below
the level of the sandstone ; and, on this worn, depressed surface,
there rests a boulder of coarse-grained granite, estimated at about
thirty tons weight. Now, no force of surging waves, surged they
ever so fiercely, is adequate to shift the position of such a mass as
this ; and we must, therefore, conclude that the huge boulder now
rests where it was originally thrown down by the floating berg
which bore it from the granite nucleus. Perhaps, however, it is not
necessary to suppose that the dike was then excavated to its present
level. It is quite conceivable that as the parts of the dike around
the boulder were worn away, its support may have been loosened,
and so its position may have shifted a little at long intervals.

71. In the sandstone of the cliffs overlooking this point we were
so fortunate as to discover a very interesting fossil, on our last excur-
sion, after the pages containing Art. 62 had been printed off. We
refer to a specimen of orthoceras communis, a true carboniferous
fossil, the occurrence of which in this locality is strongly in favour
of the view we have advanced (Arts. 48, 62), regarding the age of
these sandstones. It may, indeed, be urged that carboniferous
fossils pass upwards into the lower portion of the Permian (lower
new red) system. But we submit that orthoceras is not a genus of
which this can be said ; a very few cephalopods, allied to nautilus,
being the only animals of this order yet found in the lower Per-
mian system.

Still advancing eastwards, we meet with several other dikes — one of
these is depressed ten feet in the tideway, is on a level with the sand-
stone along the grassy surface at the base of the cliffs, and in the
front of the cliff is again worn, forming a deep chasm, which is
bounded eastwards by a bold projecting edge of the cliff, crowned
with wood. The dike on the beach, and fissure aloft, are about four-
teen feet wide each, but not exactly in the same direction, the dike
sustaining here a considerable undulation.

72. We now reach the great bed of claystone, the largest upon
this coast, and presenting many interesting appearances. It forms a

109

vein rather than a bed, as it is placed at an angle of about 15° with
the sandstone strata. The sandstone dips 12° E. of S. at about 15°,
while the claystone vein is inclined in the same direction at an angle
of about 30°. The rock is divided irregularly into prisms by joints
perpendicular to the lower surface of the vein, so that the prisms
lean back towards the south, giving the appearance, when viewed
casually, of a bedding directed northwards. The structure at the
upper surface is often schistose at right angles to the joints, or in
the direction of the vein. The base is of a uniform texture, of felspa-
thic substance, with quartz pieces imbedded. The structure varies
from a uniform claystone, or clinkstone, to a small-grained por-
phyry. The colour is pale yellow, or yellowish-white ; and at the first
view the rock might be taken for a sandstone : it has indeed been
described, when seen in its continuation in the adjoining cliff, as a
white columnar sandstone (Headrick's Arran, p. 66). The rock on
which it rests is a conglomerate; that beneath which it plunges
southwards is fine-grained sandstone. The upper surface of the vein
is very rough and jagged, with no resemblance to the style of decom-
position among sandstones. The breadth exposed upon the shore is
between thirty and forty yards. Along the level shore, where the
vein rises to the north, its lower surface is exposed in a wide fissure
hollowed out of the sandstone by the action of the sea. It is here
seen to rest upon a vein of trap, three or four feet thick, and having
the same inclination as the claystone. The line of contact is irregu-
lar, and in two or three places thin bands of conglomerate are inter-
posed between the trap and the claystone. The lower portions of
the claystone, next the trap, are harder, or converted into hornstone,
the conglomerate is much indurated, and assumes the dark colour of
the trap ; while the latter becomes a fine basalt, and is intermixed
with the sandstone below, or dispersed through it in lumps. The
posterior origin of the trap vein is thus clearly indicated. The
appearances are correctly described by Dr. MacCulloch (West. Isles,
vol. ii., p. 403), and an illustrative drawing given (vol. iii., plate
xxiv., fig. 1). The sandstone overlying the claystone along the
south side of the vein is very slightly altered.

Several dikes traverse the sandstone platform between the clay-
stone vein and the great boulder, some running nearly N. and S.,
and others nearly E. and W. The former seem to shift the latter,
producing a change in the direction of more than 20°. The dip of
the sandstone is also affected by these dikes, being thrown round
about 25° towards the west. One of the dikes, sunk more than two
feet below the sandstone, and eight inches broad, is lost on entering

110

the claystone : it may be connected with the underlying trap vein.
Another, close to the boulder, 6^ feet broad, consists in the centre
of blue-coloured rapidly decaying greenstone, and at the sides of a
hard crystalline variety of the same rock, standing above the level of
the central parts and of the adjoining sandstone.

73. The celebrated Corriegills boulder, under whose shadow we
are now resting, is of imposing dimensions, and a conspicuous object
from all parts of this coast. A few on the Corrie shore exceed it in
size ; but they are close on the edge of the granite nucleus, and we
may suppose it quite possible that if Groatfell " shook his giant sides"
under some earthquake throe, they might have been hurled head-
long from the summit to the sea level. Other causes must be
sought for the transport of this enormous mass from the parent
mountains ; and of others still farther removed, though of lesser mag-
nitude. We have already considered the only possible causes, and
attempted to estimate the evidence in favour of each (Arts. 59,
60). That to which we chiefly lean receives support from the
case before us. A crowd of lesser blocks surrounds the huge boulder
of which we speak — an association much more likely to occur in the
case of floating ice, than of currents emanating from a centre so
remote. The cubical contents, and consequently the weight, are
very difficult to estimate on account of the irregular form. The
dimensions at the base are 21 feet by 12, and the height 15 feet.
If rectangular, it would weigh 315 tons, as 12 cubic feet of granite
make a ton ; but if we deduct one -third for the conical form, which
is a large allowance, we shall have a weight of 210 tons.

74. South of the boat station under the farm-house of Corriegills,
the dikes traverse the sandstone in every possible way ; intersecting
one another at various angles, bifurcating, lesser ones lost in larger,
&c. One of them is exposed through a longer course than any other
dike on the coast. It runs a long way parallel to the line of the
shore, or almost due N. and S., till lost under the sea near Clachland
Point. It is fourteen feet wide, sunk under the sandstone in the
tideway, and sends off a branch towards the N.W., a tongue of
altered sandstone being at the bifurcation.

Two pitchstone veins, one of claystone, and one of quartziferous
porphyry, are found on this part of the shore. The lesser pitchstone
vein traverses the level shore obliquely about half-way between the
boat station and the base of Dun-fion. Within the tideway it
ranges about 72° W. of N. ; then bends about 20° towards the S.,
i. e.} runs about due W., and bends again into the former course
before it enters the sandstone cliff. Under high-water mark it is

Ill

about three feet wide, in other parts five or six feet. Seaward it is
placed conformably among the sandstone strata, and is irregular in
direction and breadth. A dike of greenstone here cuts it nearly at
right angles, but the appearances are noway remarkable. This vein,
or bed, has been overlooked by MacCulloch and succeeding observers.
The greater pitchstone vein is conspicuous, forming a broad band in
the front of the sandstone cliff farther S., and has been noticed by
every one. It occupies a slanting position in the cliff, parallel to the
sandstone strata, dipping with them towards the S.S.W. at nearly
30°, and rising towards the N.W. In the opposite direction, or
towards the S.E., it seems to plunge beneath the sea ; but the debris
here obscures it, so that its course cannot be traced to the water's
edge. Climbing up the cliff to examine it more closely, we find it
to be 13 feet 5£ inches in thickness ; of lamellar structure and
dark bottle-green colour. There is no remarkable change on the
sandstone — a slight induration merely, but the lower portion of the
pitchstone is changed into a blue-coloured porous slag-like matter,
like a pumiceous lava : this, however, is probably the mere result of
decomposition. Its exact position among the sandstone strata is
not easily determined : if parallel to them we must call it a bed, if
intersecting them, a vein. Fallen masses of the pitchstone strew
the beach ; and among these, where the path comes close on the
water, there is a dike of red quartziferous porphyry, nearly perpendi-
cular to the shore, twelve or fourteen feet broad seawards, but nar-
rowing inland to five or six feet.

A granite boulder, about one-third of the size of the one at Corrie-
gills farm-house, rests here in the tideway ; and great numbers strew
the shore all along.

75. Between the two veins of pitchstone which we have just
described, there occurs upon the flat shore another large vein of
claystone remarkable for a peculiar structure. This is developed in
those parts only which are near the junction with the sandstone, along
the south side of the vein. The appearances are fully and accu-
rately described by Dr. MacCulloch (vol. ii., p. 405). The structure
referred to " is concretionary globular, or striated ; the latter being
either found separate, or united with the globular in the same spe-
cimen. The former puts on sometimes the appearance of spots, cir-
cular or elliptic, resembling Siberian jasper. The spots, as well as
the stripes, are attended with corresponding differences of hardness,
the former arising from the globular structure, the latter from a
schistose or laminar one. The spots being often elliptical, com-
pressed or elongated, occasionally become Iamina3 in the progress of

112

elongation, passing into them by insensible degrees. The vein next
the sandstone varies much in hardness, but it cannot be said that
this induration bears any relation to its proximity to the sandstone.
The concretionary structure is seen both in the hard and soft
varieties, it is radiated fibrous, the radii sometimes diverging from a
point, and sometimes from a solid nucleus, which is further, in some
instances, surrounded by a white earthy crust. In the progress of
induration the rock at length loses its character entirelv, appearing
to pass into a substance of an indefinable nature, of a horny aspect
and dark dull green colour — partaking of the character both of cal-
cedony and pitchstone. It has been described as globular pitch-
stone ; but it is far removed from this rock by its extreme tough-
ness, want of lustre, and by the form of its fracture." Mineralo-
gists have long regarded this curious rock with much interest, and
various opinions have been held respecting its true relations, some
considering it as allied to claystone, and others to pitchstone. A
comparison of the appearances observed here with those seen at Tor-
more, and in Moneymore glen, has led us to conclude, that " the
substance of an indefinable nature" is hornstone ; and a transitional
state of these earthy matters, between claystone and pitchstone ;
the globules being due to the formation, within the fluid mass, of
crystalline centres of radiation, in the manner described in Mr. Gre-
gory Watt's Experiments (Art. 31). The radiations are of pure
quartz, while the base is of the same substance, but mixed with
colouring matter, iron or manganese, and other trifling impurities.
We shall again notice similar varieties in other places.

76. Near the pitchstone vein the high ridge of Dun-fion reaches
the coast ; and the trap which forms its summit appears in section
in the cliffs, overlying the sandstone. It presents a fa$ade of imper-
fect columns, and contrasts strongly with the stratified sandstone.
Both sink rapidly southward in the direction of the dip ; the sand-
stone is depressed below the sea-level, and the trap then occupies
the coast, forming the low point at the entrance of Lamlash bay,
and the small island in the channel. Near the point where the
sandstone disappears, some remarkable effects of trap dikes are exhi-
bited. On the west side of the point the sandstone suddenly
emerges again, and extends to Lamlash. The whole bay, indeed,
has been excavated in this red rock, which forms the base of the
cone of Holy Isle, as well as the coast on the mainland. But we
turn here meanwhile, and direct our steps to Brodick, by the sum-
mit of the ridge, which divides the two bays. Its southern side
forms a long grassy slope of gentle inclination towards Lamlash

113

bay ; towards the north it falls suddenly in steep cliffs and terraces.
As we pass up the easy ascent striking views open southwards.
Starting suddenly from the water's edge to the height of 1 ,020 feet,
Holy Isle, with its encircling sea line, fills the foreground grandly.
The bay, with its fine double sweep to King's Cross point, its
wooded banks, debouching glens, and background of dark hills,
forms the right of the picture ; to the left the glassy sea sleeps
in the sunlight, dotted with small white moving specks, and
bounded by the winding line of the Ayrshire coast, with promontory,
creek, and bay, along which the eye may range from Ardrossan
heights to the Mull of Galloway. The scene is singularly sweet and
picturesque ; without Holy Isle as an integrant part it would want
character : this stamps upon it peculiar features. The northern
mountains, so essential and expressive in most Arran landscapes, are
here hidden from us ; but when we gain the highest edge of the
ridge, they burst upon us with startling suddenness in an aspect
quite new. They are grouped in a way not seen from any other
point, and their jagged profiles are thrown into lines of singular
boldness. Not less new and striking is the aspect of the lovely
bay, with its noble castle and hanging woods, of the glens into
whose far depths the eye can reach, and of the " cottage homes"
nestling amid groups of trees, in shelter of the hills and sloping
banks which enclose the smiling fields of Brodick plain. Often as
we have come to the edge of this ridge by the same route, we have
always felt the same delightful surprise when the scene first burst
upon us.

77. This ridge consists chiefly of sandstone. Trap rocks form a
thin capping along its highest part ; they extend a little way down
the southern slope, thickening as they descend, but along the
highest ridge are so thin that sandstone occupies in some places
depressions in the ridge ; and the trap occurs only on the isolated
tabular knolls into which the ridge is cut up, especially towards the
west. The trap consists of felspar and augite mainly, with imbedded
zeolites. MacCulloch designates it augite rock ; but hornblende and
iron also occur. The sandstone close to its junction with the green-
stone of the summit is highly metamorphic, resembling a quartz
rock. Along the steep northern front also, west of Dun-Dhu, beds
of clinkstone crop out in various places, at different heights. These
are either of truly igneous origin, or are metamorphic sandstones,
altered by whin dikes, of which there are several, or by the near
proximity of the great igneous masses — greenstones, porphyries, and
pitchstone — which pervade the sandstone in this quarter. The asso-

Q

114

elation of these various products affords one of the most interesting
sections to be met with in Arran. It is best exhibited a little to
the west of the path which leads down from Dun-fion to the farm-
houses. Dun-fion, or Fingal's Fort, is the highest point on this
portion of the ridge, right over Corriegills shore, and 500 to 600
feet in height. Traces of old walls, the remains of a fortification,
are seen round the summit, but nothing whatever is known of
its history. Dun-Dhu is a prominent hill, nearly as high, a little
farther west, and standing out in front of the cliffs, to whose base
it is joined below. This hill is composed of columnar felspar por-
phyry ; and between it and the path descending from Dun-fion the
beds represented in the annexed diagram occur in a well marked
vertical section ; two veins of pitchstone and one of porphyry, with
sandstone intervening, surmounted by augitic trap.

(a a a a) Sandstone; (b) felspar porphyry ; (c c) pitchstone; (d) overlying trap.

The upper pitchstone vein, d, is about thirteen feet thick, and dips
S.W., at a small angle, probably 10° or 15°, and may, therefore, be
conformable to the sandstone, which is seen in the quarry near the
footpath to dip about S.W. at 10°. The rock is of a dark green
colour, without felspar spots, divided into beds from eight inches to
three feet in thickness ; and these beds consist of closely aggregated
prisms, or laminae splitting into prisms. The bed is very high on
the cliff, coming close up to the prismatic greenstone, but apparently
separated everywhere by altered sandstone. Its upper surface is on
a level with some of the depressions in the edge of the trap ridge ;
and, as we had repeatedly noticed a large block of pitchstone
imbedded in the soil on the southern slope, at the back of Dun-fion,
whose location there we were unable to account for, not having then
discovered this pitchstone vein, it appeared probable that the vein
might pass over the ridge. This, however, we satisfied ourselves is
not the case ; in searching for it a block of the Dun-Dhu porphyry
was found resting in a hollow of the ridge, and we conclude, there-

115

fore, that the pitchstone mass, like the porphyry, is a transported
block, borne upwards from the beds below, and deposited here in
shelter of the ridge. Along the southern slopes of the ridge we
found many granite blocks strewing the surface.

The*lower pitchstone vein, c, is fourteen feet thick, and of the
same colour and structure as the other. The vein of porphyry occu-
pies a ledge about fifty yards lower down : this ledge being on the
level of the'! front ^of Dun-Dhu, from which the porphyry extends.
The sandstone ^strata are not well seen on the ledges a a a, between
the veins, in the line of section ; but come out distinctly enough on
their continuations east and west.

Neither of the pitchstone veins has any connection with those
upon* the shore, which are far below the level of the base of our sec-
tion. Mr. Headrick, in his work on Arran, says (p. 78) : — " Pitch-
stone is seen jutting through the soil in various places to the N. and
N.W. of Dun-Dhu. In one place near a small burn it rests on red
sandstone, and makes the same angle with it." We did not visit
this spot ; but it cannot be a continuation of our veins, as these are
cut off by the Dun-Dhu porphyry.

The northern front of Dun-Dhu consists of fine columns of por-
phyry, divided at irregular intervals by flat joints. On the N.W.
side the columns are very perfect, and have a singular diverging
fan-shaped arrangement. We ascend the hill easily from the south
side, and find the summit composed of huge prismatic masses of por-
phyry, lying closely side by side almost in a horizontal position,
and in a direction from N.E. to S.W., so that their ends, cut uni-
formly off, form a wall towards the west, ten to fifteen feet in
height. Some of these columns are twenty feet in length, appa-
rently without joints : in general, however, there is an indication of
a flat jointing, at distances of four to seven feet. Most of the prisms
are four and five-sided. The rock has a gray felspar base, occasion-
ally ironshot throughout, or merely streaked with iron ; and the
imbedded crystals are of glassy felspar. Bits of quartz are also
disseminated through the base; apparently minute crystals with
their angles rounded off, as if by attrition.

No granite blocks were noticed on this detached summit ; but
many of considerable size, as much as from six to fourteen tons,
were observed close to the cliffs on the west side. They are
found in great numbers, and of large size, over all parts of the open
plateau between the base of this ridge and the shores of Brodick
bay. — Across this plateau our path homeward is by the tortuous
lane which enters on the Lamlash road immediately below the Free

116

Church. The road in itself has no object of interest ; but there is
much to beguile the way. The evening tints of rich purple-gray on
the northern mountains, beyond which the sun is now going down,
and the profile of the rugged peaks against the golden sky behind,
are glorious to look upon — the light is strong yet on the peaks of
Ben-Yim and the Cobbler, on Benlomond and the mountains of
Aberfoyle ; the broad shadow of Maoldon falls dark athwart the sea ;
but beyond this a flood of light comes streaming down the northern
channel, and brings out strongly the gray rocks of Garroch head and
the Cumbrays, and the lovely glades amid the woods of Fairlie.
The turrets of Brodick Castle are yet gilded by the sunlight which
falls in broad sheets across the lovely bay, whose glassy expanse is
crowded with fishing parties. Before we can reach our stately but
pleasant inn, the steamer has rounded Merkland point, disappeared
in the shadow of the hills, emerged again into the " lanes of light,"
and threaded her way through the fleet of boats. — Already the fair
throng has left the landing-place, scattered now in gleeful groups
along the various roads.

EXCURSION III.
To THE SUMMIT or GOATFELL.

78. GOATFELL is an unmeaning corruption of the native name of
this mountain. Gaoth (ga5) is the Gaelic word for wind ; this may
be the origin of the first part of the name ; with the animal indi-
cated the mountain has no sort of connection. Then, Fell is not a
Scottish word ; it belongs to the North of England, and to Scandi-
navia in its form of fjeld or field, applied appropriately to the wide
flat mountain plateaus of South Norway. Bein, or with the aspirate
Bhein (ban, or ben, ven), is a mountain. Pen is the English form,
as in Penyghent, Pendle hill, and hence the Latin term Pennine for
a principal range. Thus the name would be Gaoth-bhein, or Bein-
gaoth — the hill of the winds — not very expressive or special as
regards this hill more than others standing prominent. But those
who gave the name perhaps knew no higher hill; and there is a
peculiar effect often seen here to which the name may perhaps have
reference. The Ben-Ghnuis or western ridge first arrests the vapours
ascending from the western sea, and condenses them into a dark

117

sinuous bank, from whose shattered edge masses float away when
the breeze gets up, and, dashing against the flat side of the ridge of
Goatfell, are driven in rapid eddies round its south end or over its
upper edge. To one looking up from the quiet depths below, this
would suggest the existence of a furious gale upon the summit. As
the weather thickens and the clouds accumulate, the cone gets com-
pletely hidden, and the rolling vapours pass even lower than the mill-
dam, veiling the edge of the great waterfall, which then seems to
issue directly from the clouds.

But such a day as this will not suit for our walk ; we must wait
for bright skies and still air — few walks in Arran will then please us
more. Every lover of mountains has a keen desire to climb the
highest summit within his reach, and many will choose this walk
for their first excursion.

79. The woods which stretch westwards from the castle are
crossed by two roads, by either of which we may pass upwards into
the moors. A path lies near the east bank of the Cnocan burn, as
far as the mill-dam, where this stream is gathered from many heads.
Beyond this a track is marked out among the granite blocks to the
east shoulder of the mountain ; thence, along the edge of the ridge,
a rugged path conducts us to the summit, over huge masses of rock,
and along the edge of Cyclopean walls. But the geologist has much
to see on the ascent which this route will not show him, and we
must conduct him by another way.

Beds of fossiliferous limestone occur in the woods N.W. of
Brodick castle ; they belong, of course, to the carboniferous system,
and are higher in the series than the sandstones, which appear
in the bed and banks of the burn before it enters the wood. They
are regarded by Murchison and Sedgwick as an upthrow of the
Corrie beds, a theory to which we do not object ; but the facts may
be explained otherwise (Art. 52). These sandstones are succeeded
by the old red as we ascend the burn above the wood, the junction
being somewhere about the place where the wall enclosing the new
plantation abuts against the bank of the stream. But the contact
is not seen, nor is there any gradation visible. The old red is here
a hard quartzose slaty sandstone, with many thin brown laminae,
and elliptic blue or white claygalls : the dip is back against the
slate of the mountain, contrary to that of the overlying carboni-
ferous beds, at angles varying from 55° to 70° W. of magnetic N.
As we advance the strata become much obscured by debris ; and a
little above the point where the west burn enters the main stream
the dip is reversed or toward S.S.E., at about 65° to 70°. The rock

118

is here coarser, and contains imbedded masses of resinous quartz and
dark blue slate ; farther on it is darker and finer, with clay galls, and
the dip again appears to be toward the slate, but the stratification is
obscure. In front of the first waterfall, amid a group of birch trees,
a mass of quartziferous horn stone porphyry lies across the bed of the
stream, but seems to terminate against the bank on the west side 5
on the east side its extension cannot be traced, so that most probably
it is not a dike. It is a beautiful rock, and if readily obtained in
quantity might be used for ornamental purposes. The base is a
dark reddish hornstone, containing crystals of glassy felspar, and
round bits of quartz. There are beds of conglomerate here ; and
the strata lean toward the slate, but less " end on ;" the dip being
about 30° W. of magnetic N.

We are now approaching the junction of the old red sandstone
with the slate; but as this is not well seen in the bed of the main
stream, it will be more instructive to diverge to the left, up the
course of the west branch, as far as the dark brow of slate, where
the hill suddenly rises. Passing up the bed of this west-burn, we
find the common red rock and conglomerate succeeded by flinty or
quartzose sandstone, obviously metamorphic. The cause of this
change is soon discovered. At a waterfall on the burn there is an
outburst of a peculiar granite amid the sandstone strata. This is
an intimate mixture of quartz and felspar, without mica; in fact, the
Surite or Weisstein of mineralogists. It extends many yards in the
bed and banks — how far cannot be determined. Between it and the
rocky brow, which is formed of the common dark slate, there are
various metamorphic beds, conducting us by insensible gradations
into the true slate. Some of these are white and gray flinty slates,
others fine-grained hard sandstones. It is thus difficult to decide
to which series the beds ought to be referred. The strata have been
assimilated by the metamorphic action to which both series have
been alike subjected. A similar case occurs on the White Water, as
already noticed (Art. 52, p. 76).

Returning now to the bed of the main stream, and entering it
some way above the waterfall at which we turned off", we find similar
white and gray quartzites about fifty yards in front of a deep chasm,
with a waterfall, cut out of the slate rock. The sandstone is not
seen in close proximity ; but the junction must be near, as this is
the first point at which the slate appears in the bed or banks.
Two dikes of greenstone, from opposite sides of the pool, unite at
the edge of the fall, twice bifurcate, and twice unite again, enclos-
ing two long elliptic masses of altered slate, and then continue as

119

one dike right up the chasm. The branches are three to four feet
wide; and the joint breadth, as one dike, eight or ten. The dike
undulates in its course from 30° to 40°, conforming to the course of
the chasm. The chasm is, in fact, due to the dike; an original
depression, produced by a fault or the irruption of the dike,
determined the channel for the stream, and along the course of the
dike the water met with least resistance in its work of disintegration.
The chasm is nearly half a mile in length, with perpendicular walls
ten to fifteen in height, above which the banks rise very steeply on
both sides. It runs in against the great sheets of slate, forming the
waterfall below the mill-dam. At the base of these sheets the
dike is seen again, interrupted or broken off in one place by the slate,
from beneath which it again emerges, and appears upon the high
brows above in the bed of a small stream entering from the N.E.

80. We are now at the famous junction of granite and slate close
to the mill-dam. The appearances have been often described ; we
shall quote the very clear account given by Professor Ramsay
(Arran, p. 4) : — " The absolute junction of the two rocks is not here
visible; but that it is in the immediate neighbourhood, probably in
the bed of the dam, is clearly shown by the appearance of a granite
vein, about one foot broad, which penetrates the strata, and crosses
the bed of the stream about ten yards below the artificial wall which
confines the water of the dam; thus indicating its intrusion, while
in a state of fusion, into the stratified deposit with which it came
in contact. The granite is of a yellowish colour, fine-grained and
compact in texture, and consists principally of felspar. The slate is
exceedingly tortuous; and the strata are intermingled with nume-
rous veins of quartz of varying sizes, and which generally alternate
with the slaty strata in regular minute laminae." This description
is correct and well stated; but an important fact has escaped notice
altogether. It has not, indeed, been alluded to by any one of the
many observers who have visited this locality, owing probably to
the state of the water in the river at the time when this junction was
examined. We refer to a dike of greenstone which crosses the river
diagonally, ranging about 20° E. of N., and about thirty feet wide.
It enters the east bank of the stream under the mound or wall of the
dam, and is seen again on the surface, a little way toward the N.E.,
but is soon lost under the heaps of granite blocks. The strata
of slate range 65° E. of N., or almost E. and W. by the compass,
dipping 25° E. of S., at an angle of 70°. Thus the direction of the
dike makes an angle of 40° with that of the slate. Now, there are
granite veins in this dike; and these cross out into the slate on the

120

east side of the dike, continuously without a change of direction.
There is no mistaking the rocks, both the greenstone and slate are
perfectly well marked; a portion of the former, traversed by the
veins, has distinct acicular crystals of white felspar, and that con-
centric structure so peculiar to this rock. The state is quite
homogeneous — a dark blue hard quartzite, in some specimens resem-
bling Lydian stone — but the alteration from its ordinary state is not
remarkable. The principal granite vein is several inches (six to
eight) wide, and is traceable in the greenstone through a space of
fifteen or twenty yards ; and runs right on into the slate. Several
smaller veins ramify through the greenstone, dividing and then
uniting again. These have the structure so well described in the
above extract. We conclude that the slate was first injected by the
greenstone dike; and that the irruption of the granite, at a sub-
sequent period, pierced through both of these rocks. The case is
very interesting, being the only one in Arran, that we know of, in
which greenstone is proved to have been erupted anterior to the
injection of the granite amid the strata of slate.

81. We recommend the geologist, who is not deterred by the
prospect of "a pretty stiff pull," to mount at once by the southern
shoulder of Groatfell, avoiding the common pathway, already pointed
out, which presents much less to interest him. He will thus have
an opportunity of examining those huge natural ramparts of granite
blocks, piled mass on mass to a great height, like the Cyclopean walls
of Tadmor or Heliopolis, and of studying the structure of a granite
mountain, the varieties of the rock, and its peculiar style of decom-
position. We especially recommend this course, if he has not
accompanied us on our First Excursion.

We have now reached the south summit of Goatfell, the highest
point in the island, elevated 2,875 feet above half-tide level. The
north summit is 247 feet lower. There is not, perhaps, in Scotland,
another mountain peak which looks abroad upon a scene combining
the same variety of grand features. Many afford wider and finer
mountain views ; here the eye ranges over a vast extent of broken
coast, the whole expanse of the noble frith, and its many narrow
branches winding far in amid mountain solitudes. How grand from
this commanding height are the surrounding peaks and rugged
ridges, and the profound dividing glens! what lovely pictures in
their glassy frames are these sister islands ! how stirring the rapid
movements of life all day on the inner frith ! what a world of human
interest in that great ocean steamer starting on her outward voyage !
The " sweep of the circling horizon" embraces a magnificent amphi-

121

theatre — reaching from the mountains of Donegal and Londonderry,
on the S.W., to Ben-Lomond and Benledi on the N.E. ; from Ben-
Cruachan and the mountains of Mull, on the N. and N.W., to the
ranges of the South Highlands and the Mull of Galloway in the
opposite direction.*

As the day verges into evening the Western Isles stand grandly
up in a sea of molten gold, which, rising far out westwards, blends
with masses of gorgeous clouds, " set on fire with redness." — Later

still,

" the sun descending

Leaves upon the level water

One long track and trail of splendour."

There is not much of mere geological interest on the summit of
Goatfell. A claystone vein occupies a fissure to the N.W. of the
cairn, and there are traces of a greenstone dike. Many veins of
fine granite, which we regard as cotemporaneous, and not injected,
intersect the coarse-grained variety of which the whole mountain
consists. Dr. MacCulloch long ago pointed out a magnetic property
in the granite here, which he afterwards confirmed by observations
made on other mountains in Scotland. (West. Isles, ii., 451, and
Geol. Trans., 1st Series, vol. ii., p. 430, and vol. iv., p. 124.)

82. There are various routes by which we may descend. Those into
Glen Kosa and by the Rosa col must be carefully selected, as they
are very dangerous in some places. There are two more instructive
than the rest for the geologist. One is by the plateau S.W. of the
mill-dam, along the boundary of the granite and slate, where some
fine junctions, granite veins and contorted schist, may be studied.
A good example of a " roche moutonnee" may be seen on the edge
of the plateau a quarter of a mile S.W.. of the mill-dam. The
exposed horizontal surface is fourteen or fifteen yards in extent,
rounded nicely off diagonally to the laminae; the N.W. front or
vertical face is also ground off, but the opposite face, turned
towards the S.E., retains its original form. This indicates the
direction of the abrading force. — The other route is eastwards,
by Maoldon and the White Water. Crossing to Maoldon from the
eastern ridge of Goatfell, we pass the slate and old red sandstone
bands, and come upon the carboniferous sandstone ; but no junctions
are visible on this line. The top of Maoldon, about 1,000 feet
high, is composed of soft red sandstone, dipping 25° E. of S., at

* We have never decidedly identified Ben-Nevis, but believe that it may be seen
from Goatfell. The mountains in the Isle of Man are probably visible in very
favourable weather ; — in that direction Ailsa Craig is a fine object.

122

15° to 20°, and thus the strata are " end on" to the granite. It is
strewn with granite blocks of moderate size. The N. and N.E. fronts
are very precipitous; the western part of the precipice is intersected
by a greenstone dike about fifteen feet broad, ranging 25° W. of N.,
and inclined towards the E. at an angle of about 15°. It forms a deep
chasm in the cliff, over which the sandstone rises in a lofty wall.
The amount of wearing here is prodigious, and we cannot conceive
how it can have been effected without the action of the sea. Yet
the place is many hundred feet higher than the ancient level,
indicated by the raised beach so often mentioned already. We
must, therefore, call in the agency of the sea, during the elevation of
the land at an earlier period. — Through a narrow passage between
the dike and the sandstone wall, we can descend to the base of the
cliffs. A remarkable alteration is produced in the sandstone by
this great dike.

In the broken ground in front of the cliffs a great bed of lime-
stone occurs ; it is similar to that at Corrie, with the same number of
integrant strata, each of which is, however, thinner than at Corrie,
— and with the same assemblage of fossils. It has been already
noticed (Art. 52, p. 75), as probably an upthrow of the Corrie beds;
those in the woods N.W. of Brodick Castle may have the same
origin; there being thus, in all, four upthrows of this stratum,
separated by four great faults. Our reasons for doubting this view
have been stated already (Art. 52).

There is little else worthy of notice here ; it is a wild bosky place,
encumbered with huge fallen masses of sandstone, and with granite
blocks, among which many pretty ferns and flowering plants find
suitable habitats. Before passing down to the high road, on his
way homeward, the geologist will do well to visit the interesting
junction in the bed of the White Water, near the fall at which the
burn issues from a wild corrie. The metamorphism here is very
remarkable ; the granite becomes a blue compact felspar or eurite ;
the narrow belt of slate is streaked with white veins, and contains
crystals of felspar; while from the slate to the sandstone there is a
similar passage, analogous to that which has been described already
as occurring in the west branch of the Cnocan burn. The student
must be prepared to encounter many difficulties in his ascent of the
channel ; and to submit, now and again, with the best grace he may,
to a shower-bath from the dashing spray as the water bounds from
ledge to ledge of the long fall.

83. The largest boulder in the island is well deserving of a visit
before we pass down to the highway. It rests on the edge of the

123

ancient seacliff, a short distance N. of the White Water. It is a true
boulder, — granite reposing upon sandstone. We estimated the weight
at more than 2,000 tons. What force could have hurled a mass so
enormous from the mountain-side ? Not gravity urging its descent ;
unless, perhaps, the first impulse was given by an earthquake, for
the slope of the hill-side is gradual, and the mass itself ill adapted
for easy rolling. But if we admit the agency of ice, we have a
force adequate to the transport. This transport took place before
the present level of land and water was established ; the cliff was
not yet cut out from the sloping hill-side ; the bed on which the
boulder now reposes was the sea bottom, and in the glacial period it
may have glided down upon icy sheets descending from the corries,
or been borne off by a berg which deposited here the heaviest portion
of its load. A sister block rests upon the same cliff, on the south side
of the burn; but its dimensions are much less. The shore is
strewed with multitudes of similar masses of all sizes.

84. In passing along the road towards Brodick, we are upon sand-
stones of the carboniferous system, dipping south at small angles, but
often disturbed by the numerous dikes which cross the strata in
various directions. On our right is the picturesque cliff, the old sea-
margin, hollowed into caves, and bearing other marks of the former
action of the waves. From these caves, from the summit of the
cliffs, and from the low terrace along which the road is carried, once
the sea bottom, many marine shells have been obtained. The great
proportion are the same as those now inhabiting the shores of the
Clyde; but with them are associated a few of those arctic species
which we have already given (Art. 7), in the list kindly furnished by
Mr. Smith, of Jordanhill; thus indicating the prevalence of the same
conditions which obtained during the era of the boulder clay.

Between Brodick pier and the fine picturesque group of ash
trees near the beach, there are some remarkable dikes which disturb
the stratification of the sandstone, and are obviously connected here,
as at the other extremity of the beach (Art. 70), with the appear-
ance of the rock from beneath the sands. The ridge of gravel and
sand dividing the beach from the marsh behind is the joint work of
the sea and the two streams. The Cloy burn formerly entered the
bay at Invercloy, as the name of the village implies ; the course was
changed by a bar cast up in a storm, and it has now for a long
period followed the winding course which unites it with the Rosa
burn before reaching the sea.

124

EXCUESION IV.

THE WAYSIDE MUSEUM.

85. THE student of geology will make little progress in this
delightful science without a thorough practical acquaintance with the
mineralogical distinctions of rocks. He must first know a few of
the common simple minerals ; quartz and its varieties, amethyst,
smoke quartz, hornstone, jasper, &c. ; felspar, and its varieties, as glassy
and compact felspar, and albite; mica, talc, chlorite, hornblende,
augite, hypersthene, olivine, and calcspar. Of these, quartz, felspar,
mica, hornblende, and augite are the components of almost all the
mountain rocks of the globe. Knowing these, he will easily make
out the composition of most rocks. With every term a definite idea
will then be connected, and the study of the subject will be smooth
and pleasant henceforward. Arran is an epitome of the globe,
our Wayside Museum is an epitome of Arran, in so far as a
collection of rocks is concerned. In two or three visits to this col-
lection, with a book in his hand descriptive of rocks, or a friend by
his side qualified to instruct him, the student will gam an acquaint-
ance with rocks which he can never learn from hand specimens, —
an acquaintance which is absolutely necessary to all true progress in
the science.

The collection of which we speak is easily visited. Leaving the
village of Lower Invercloy at the smithy, and passing up the hill
along the old Lamlash road, we are upon it at once. It is simply a
stone fence, bounding the road on the east side, and reaching from
the brow of the old seacliff to the top of the hill. The stones of
which it consists were gathered from the adjoining fields, across
whose surface they were spread out during the " diluvial era," or the
" glacial period."

We shall merely name the principal rocks found here, without
attempting any description. Granite, several varieties; primary
slate, banded like gneiss; hornblende rock, mica clay and chlorite
slates, and quartz ; red sandstone and conglomerate, containing
mica-slate and quartz pebbles ; pitchstone and pitchstone porphyry,
several varieties; a complete suite of the trap rocks ; — from coarse
crystalline greenstone through basalt to pitchstone, a regular gra-
dation may be traced. There are two principal varieties of trap
porphyry, that is, fine greenstone containing imbedded crystals —

125

not properly a porphyry, for the base ought to be simple. One is
speckled with felspar dots, the other more homogeneous and dark-
based. Concentric spheroids of greenstone occur, and several varieties
of black basalt. A few blocks are met with of a very interesting
rock, which we have never found in situ in Arran ; it is intermediate
between basalt and pitchstone, and links them together as products
of fire generated at different stages of the cooling process. It is hard
and tough, and almost homogeneous, like basalt, while it has the
semivitreous aspect and colour of a dark blue pitchstone.

86. We may visit two other objects of interest by the same way-
side. Descending from the top of the ridge into the Birk glen,
and crossing the burn, we come upon the great pitchstone vein. It
crosses the road nearly at right angles, ranging 35° N. of E., and
is thirty feet broad. This is not, however, the true breadth of the
vein at right angles to its upper and lower surfaces, but merely the
extent of the upper surface here stript of its sandstone covering.
It is green, of lamellar structure, and contains in parts felspar
crystals, giving a porphyritic aspect. Thin white films form on
the exposed surfaces, by disintegration; and when in contact with
running water it decomposes into a tenacious clay, which forms
a thin coating on the surface. The vein is seen in the bed of the
burn, of about the same width. The contact with the sandstone is
not very well seen ; but there does not appear to be any remarkable
alteration upon it. A dike or bed of trap is connected with the
vein on the lower side ; but the relation of the two rocks cannot be
made out clearly. — The other object of interest to which we referred,
is a vein or bed of claystone on the east side of the new Lamlash
road, almost in the line of bearing of the pitchstone. A quarry of
road metal has here been opened upon it; eastwards it can only be
traced a very little way, but westwards it is seen below the road in
the direction of the pitchstone vein. Its range thus seems to be
60° N. of E., or slightly transverse to the other vein, which probably
cuts it off, as the claystone is not seen in the river bed on either side
of the pitchstone vein. In the quarry the claystone splits below
into rhombic blocks ; in the upper part it is slaty. We have referred
to this quarry already (Art. 57, p. 83); and also alluded to the
many claystone beds on the north front of the ridge of Dun-fion.

We may return by the new Lamlash road; but there is more
variety to be met with in descending the stream, and passing through
the ornamental grounds connected with the hotel. The sandstone
strata are well exposed, and there are some curious dikes.

126

EXCURSION V.
To THE NORTH SHORE .

87. THE coast section from Corrie to Loch Eanza is full of
interest. A long summer's day will be required to examine it
carefully, — several days, if we stop to collect the fossils which abound
in some of the beds. The scenery, too, is full of beauty, in parts
bold and picturesque in the extreme : we shall be tempted to stop very
often to add some new treasure to our portfolio. Leaving Inver-
cloy by the first steamer for Glasgow, we shall be at Corrie for an
early breakfast, and be ready to start fresh while the day is yet
young. Corrie is, in fact, for several excursions an admirable
point of departure.*

The strata at the base of the carboniferous system, and their
contact with the old red sandstone, are well exposed upon the shore.
We shall trace them in ascending order, beginning a quarter of a
mile north of Corrie, at the march of Achab farm, where the road
bends toward the N.W.f This is the base of the series; but it is
not a well defined base ; — there is, in fact, a gradual passage from
the old red system into the carboniferous strata. The old red is
here a conglomerate ; and is overlaid by a limestone with im-
bedded pebbles, the same as those in the conglomerate, forming a
calcareous conglomerate. This bed is followed by gray sandstone
and concretionary limestone, or cornstone, consisting of red nodules,
imbedded in shale. A bed of gray limestone succeeds, and
then various beds of sandstone and shale, till we reach an enor-
mous vein or dike of trap, which occupies the shore for more
than 300 yards. In this are found basalt, greenstone, amgy-
daloid, and concretionary trap, exfoliating in concentric coats ; and
it is traversed by numerous veins of calc spar, steatite, and quartz . J
The next beds seen are a red and a gray limestone ; there is then a
whin dike; south of which, from the gate upon the road to the
limestone quarry, the shore is occupied by sandstone. The strata

* A handsome and commodious hotel has very recently been erected; and under
its present management is a most comfortable and pleasant residence for a few days.

f Mr. Douglas, postmaster at Corrie, and his two sons, are highly intelligent
and obliging persons, well acquainted with the strata in the vicinity, and with the
geology of the island generally.

J Ramsay's Arran, p. 20.

127

of limestone extend up the hill, rising towards the north, and dip-
ping S.E. at 36°. The rock is of a bluish-gray colour, about
twenty feet thick, and consists of twenty-two beds of limestone,
interstratified with the same number of beds of red shale, the thickest
stratum seldom reaching one foot. The workings are inclined
adits descending in the line of dip. Over the limestone are shales
with hematitic iron ore. Several dikes traverse the limestone, and
alter its structure ; — fossils abound, but are procured with difficulty.
It has been remarked, as indicating the tranquil nature of the
deposit, that the large producti uniformly rest with the convex
side of the valve downwards. In the sandstone upon the shore in
front of the village several common species of coal plants are found.
A little south of Corrie, near the fall on Lochrim burn, another
bed of limestone occurs; that under Maoldon has been noticed
already (Art. 82) . The many interesting trap dikes have also been
noticed; — and those curious irregular ridges on the surface of the
sandstone mentioned as occurring on the Corregills shore, are even
more remarkable here. They sometimes stand up six or eight feet
above the surface, and have very sharp jagged edges. In most
cases they are independent of whin dikes, and consist of matter
originally less liable to disintegrate than the sandstone, and prob-
ably introduced into fissures in this rock after it had consolidated.

88. We return now to the contact of the carboniferous rocks
with the old red sandstone at the march of Achab farm, and
follow the latter rock northward along the coast. Expanding
inland, it rises into high cliffs. The forms into which these
have been moulded by the action of the sea, the disposition of the
natural wood upon them, and the huge granite blocks which
stand prominent by the road-side, give a unique and most
picturesque character to this part of the coast. One of the largest
blocks (on the western edge of the road among trees) we estimated
at above 200 tons ; farther north on the eastern edge of the road is
another very large block standing upright on its apex, perhaps let
down so from a floating berg, or originally imbedded in sandstone,
afterwards worn away as the tide ebbed and flowed around. A
melancholy interest attaches to another boulder south of the
march of Achab farm. A garrison of eighty men had been left in
Brodick Castle by Cromwell ; against these the natives became so
irritated, on account of the excesses of some of the soldiers, that
when they were out upon a foraging party in this direction, the
Arran men rose against them, and put them all to the sword,
except one poor fellow who escaped, and hid under this stone.

128

His place of concealment being soon discovered, he shared the fate
of his companions.

We cross the Sannox burn by a rustic bridge, where it comes
flashing down along its bed of granite sand, among wild copsewood,
through green shadows and gleams of sunlight. Our path is now
by the farm-house on the shore ; but we must not pass so near the
finest view of Glen Sannox without stopping for a little to look upon
it. This point will be readily found upon the road towards North
Sannox house. We look down upon a broken foreground, sloping
on both sides towards the stream. On the right the glen is bounded
by the long, steep ridge of Suithi-Fergus and the Castles ; on the left
by that of Cioch-na-Oigh and the prolonged ridge of Goatfell. Cior-
Mhor stands proudly up, closing the long vista. — We return to the
shore. The high ridge of ground dividing North and South Glen
Sannox terminates on the shore, in a precipice called the Blue Bock,
from a decomposition taking place upon it, due to the presence of
iron and manganese, acted on by trickling streamlets. Here, and
along the shore, the strata of old red still retain their southern dip,
at a small angle. But when we cross the North Sannox water, we
find the inclination southwards much less; and as we advance a
little, the strata become horizontal. Still advancing, we find them
dipping in the opposite direction, at angles gradually increasing till
the original dip of 15° or 20° is reached, but now directed N.N.W.,
instead of S.S.E. The line from which these opposite dips are
thus directed, and which is nearly in the direction of North Sannox
Glen, is called the Anticlinal axis. The name was applied by
Murchison and Sedgwick; but the relations of the strata were first
pointed out by MacCulloch. It is obvious, then, that the strata are
successively newer as we advance along the shore towards Loch
Banza. We shall pass over their basset edges rising southwards,
the dips being northerly, and the inclinations on the shore from 10°
to 15° and 20°; while on the face of the hills above they are from
50° to 70°, but in both cases alike towards the same point of the
compass.

The Old Bed here is cut by several dikes, of which two are
extremely interesting. One of these is about half-a-mile north of
North Sannox burn; it entangles a mass of altered sandstone,
wedge-shaped at either end, five yards long and seven inches thick ;
the range is nearly north-west. The other dike is at the angle of the
shore, where the Fallen Bocks first come into view, at little more
than half-a-mile distant. The dike is best seen in the sand under
the grassy bank. The structure of the trap varies, much of it being

129

a fine blue greenstone or basalt. The change on the sandstone is
remarkable. The interlacing of the two rocks, and intrusion of string-
like veins of trap among the sandstone strata, as forcibly attest as
any dike in Arran the irruption of a liquid stream of lava into the
crevices of a fissured mass.

The Fallen Rocks are about two miles from Sannox ; they are an
immense debacle of masses of old red sandstone hurled from a hill
above where an overhanging cliff gave way ; and now strewing the
beach and steep slope in magnificent confusion. They seem freshly
fallen, yet Headrick described them fifty years ago as we see them
now.

89. Immediately west of the Fallen Bocks, we come on the lower
beds of the carboniferous series following conformably on the old red
sandstone. They are very similar to the corresponding beds at the
march of Achab farm, n<?ar Corrie; a calcareous conglomerate, with
beds of white limestone, being the lowest. These are followed by
sandstone and shale, with nodular limestone and thick bedded red
and white sandstones, till we reach the limestones near the Salt Pans,
which are the same as the Corrie beds. But we must not omit to
notice the great trap beds of Lagantuin bay, which upturn the
shales from their usual inclination of 20° to an angle of 58°. These
traps are amygdaloid with zeolites, steatite, and carbonate of lime,
claystone, and porphyrytic greenstone or trap porphyry with
crystals of diallage. The coast section near the coal pits is very
interesting ; it is thus given by Murchison and Sedgwick, as seen
west of Millstone point : —

1. Blue shale, with limestone, . . . 25 feet,

2. White sandstone, 2,700 „

3. Carboniferous limestone and shale, alternating, 120 „

4. White sandstone and variegated shales, . 2,000 „

Sandstone and shale, containing seams of coal, succeed these till
the beach is obscured by shingle. The principal seam is three or
four feet thick; but has been worked out, as far, at least, as the
level of the sea, which now invades the seam. It was used only
at the adjoining salt and lime works, and never exported. There
were workings on two or three seams in the direction of the
dip, which is nearly at 45° north, but all were abandoned, when,
from the depth of the workings, the sea gained access to the pits.
The coal is of that variety called blind coal, containing an unusual
quantity of carbon, and burning without flame or smoke. Many vege-
table impressions, chiefly ferns and calamites, were found in the coal

130

below the shale; the stems of the latter being formed of a hard coal
with a bright shining fracture. This character of the coal may be
partly due to the action of several dikes which here cut the
strata. An adit was opened in the hill above on the strike of
the seam, but no coal was found.

A little to the west of this, beyond a shingly beach, sandstones
and shales again appear. The shales contain beds of ironstone,
some of which have the structure of septaria; and these, with
the variegated shales, form on the shore a flat platform, with a
tesselated appearance, like a mosaic pavement. " I doubt," says
Mr. Headrick (p. 210), " if the most skilful mason, or even a mathe-
matician, could produce anything more regular or more beautiful."

Farther on — about half-way between the Salt Pans and the " Cock
of Arran" — several beds of red limestone, rich in fossils, and of red
shale, occur. It is interesting to notice the perforations of pholades
in the limestone above the level of the present tides, as being a
striking collateral proof of that change of level to which we have
so often alluded.

These limestones are succeeded by a series of sandstones, shales,
and fine conglomerates, overlaid in their turn by variegated marls,
containing nodular ironstone, and by white sandstone. Over the
latter, a little way east of the Cock, lie beds of fine red sand, alternat-
ing with fine conglomerate, the dip of both being 65° W. of N., at
23°. These beds, with the white and red sandstones which succeed
them westwards till the schist is reached beyond the Scriden, are the
uppermost members of the whole series, which begins to overlie the
old red sandstone near the Fallen Rocks. From their position and
mineral character they have been classed as new red sandstone by
Murchison, Sedgwick, and Ramsay. Mineralogically, they have a
much greater resemblance to lower permian strata than any of the
rocks in the southern district ; but we refer them, notwithstanding,
to the upper carboniferous series, till fossils shall be found which
may decide the question.

The Cock of Arran near which this series begins, is a large iso-
lated mass of sandstone, resting on the beach, a noted landmark among
sailors. When seen in front from the sea the block had the form of a
cock, with expanded wings, in the act of crowing. The resemblance is
now less striking, as the head has been broken off. Beside this block
there are two singular whin dikes close together, on the flat beach,
about two feet wide. They terminate in the sandstone, almost
opposite to one another, and are prolonged in contrary directions.

90. The following list comprises all the known fossils of the car-

131

boniferous series in Arran. The old red sandstone has not as yet
yielded any organic remains :* —

Plants.

Stigmaria ficoides : Corrie sandstone ; Salt Pans.

Sphenopteris ? Salt Pans.

Calamites ? Corrie ; Salt Pans.

Crustacea.
Phillipsia pustulata : Salt Pans, in red shale.

Brachiopoda.

Productus giganteus. Orthis resupinata.

Spirifer bisulcatus.

— undulatus.

— octoplicatus.

Scoticus.

- spinosus.
latissimus.

- Martini.
punctatus.

lobatus.

costatus.

Chonetes variolata.

lineatus.
— papillionaceus ?
Rhynconella pleurodon.
Athyris ambigua.
— another ?

Avicula modiolaris.

Monomyaria — Dimyaria .

pecten.

Venus, two species ?
Nucula undulata.

Nucula attenuata.
Cardium alaeforme.
Cypricardia rhombea.

Gasteropoda.
Buccinum acutum : above Corrie, in red shale.

ampullaria, do.

Natica elliptica, do.

variata, do

Murchisonia? do.

Bellerophon striatus, do.

Cephalopoda.
Orthoceras (undetermined) : Corriegills, in sandstone, f

unguis : Corrie, in shale.

attenuatum : Salt Pans, in shale.

Radiata.
Archaeocidaris Urii.

Zoophyta.

Cvathophyllum, two species ?
Lithostrotion Martini.
Cellapora Urii.

Calamopora tumida.
Fenestella flustriformis.
Stems of Encrinites.

The Scriden is a headland whose base is strewed with immense

* Many of the best fossils on this list were collected by Mr. John Young, of the
Hunterian Museum, Glasgow. The trilobite was found by him at the Salt Pans in
September last. Nelson Mitchell, Esq., of Glasgow, who has carefully examined
the limestones and shales in several localities, has supplied several good species. I
owe also to his kindness many interesting observations on different parts of the
island. Several species have been kindly made known to me by Thos. Chapman,
Esq., of Glasgow. The species whose localities are not given are common to the
€orrie beds and those of the north shore.

f The sandstone is so much altered by the dikes which here traverse it that the
species cannot be exactly determined.

132

masses of sandstone. These fell about 100 years ago with a loud
noise heard in Bute and Argyll. The debacle is more extensive than
that of the Fallen Rocks, but inferior in grandeur. It was produced
by a landslip of the mountain side, the traces of which yet remain
in a long deep rent near the summit. Scrambling for a long way
among the fallen masses, we reach an open shingly beach, along
which the line of the old slate advancing from the interior, striken
the shore, and cuts off the red sandstone ; but the nature of the
ground does not permit the junction to be seen. The slate here dips
about S.E, at 40°. The change takes place near a glen, with a burn,
called Alt-Mhor (large burn.) The variety called chlorite slate
occurs here, and quartz abounds in veins and beds in the slate.

91. A short distance forward, at Newton point, where the coast
bends round into Loch Ranza, and a small stream, called Alt-Beith
(birch burn)> enters the sea, there occurs one of the most instruc-
tive sections to be seen in Arran. Strata of sandstone again occupy
the shore for 300 yards, dipping into the sea, and resting along the
platform in front of the cliffs upon the upturned edges of the strata
of slate. TKese make an angle of 40° with the horizon, and dip 40°
E. of S,; the strata of sandstone are inclined at 25° and dip 55° W.
of N. ; the dips being thus nearly in opposite directions (see Art.
45, sub Jin.) This unconformability indicates that the slate, itself
a sedimentary deposit, had not only been formed in this regular stra-
tification, but had undergone a general disturbance, before the sand-
stone beds were thrown down upon it. The position of the slate-
strata has no relation to the granite of the nucleus; — the dip and
strike are related to the great axis of elevation traversing the country
in the direction of the Grampian chain. This position had been
acquired before the Arran granite was injected amid the strata of
slate, and ere yet any of the sandstone beds which succeed it had
been deposited. These sandstones (old red and carboniferous) are
conformable to one another, and the deposits blend, at both sides of
the section, Achab farm and the Fallen Rocks-. But we see here,
as repeatedly noticed already, that neither deposit has any relation
to the stratification of the slate, which had sustained extensive dislo-
cation before the deposit of the old red sandstone had begun. The
cut annexed represents the appearances at this place.

The sandstone strata here alternate with beds of limestone and con-
glomerate. The lowest bed, b, next the slate, a, is a hard crystalline
white limestone, about six feet thick ; it contains quartz pebbles,
schist, and diffused siliceous matter ; and is without fossils. There
are several beds higher in the series, but the thickness is less.

133

The total thickness of the various beds is not more than fifty
ieet. Whin dikes traverse both the slate and sandstone. The

(a) Slate; (b 5) beds of white siliceous limestone ; (c) sandstone and conglomerate.

presence of this peculiar limestone fixes the age of the deposit, which
resembles, in all respects, that already noticed at Achab farm, and
the Fallen Bocks, as forming a gradation from the old red to the
carboniferous series — there being a difficulty in determining to which
it ought to be assigned. We are inclined to the view that it is the
lowest member of the carboniferous system. The occurrence of the
limestone here has been noticed by Jamieson (Min. of Scot. Isl., vol. i.,
p. 78, edit. 1800), from whom our cut is taken; by Headrick (p. 206,
1807); and by MacCulloch (vol. ii., pp. 376, 356, 1819). Later
writers have classed it as new red sandstone, overlooking the lime-
stone, and have given the dips erroneously. The deposit is a mere
isolated patch, and has no connection with the sandstones eastwards,
which abut upon the slate, and are clearly the uppermost members
of the carboniferous series in this part of the island.

Very few granite blocks occur along the north shore, and none of
more than two to three tons in weight. But as we enter Loch
Banza and its glen opening directly on the granite nucleus, we meet
with boulders of great magnitude. Two of this kind, with many
lesser, rest on the beach at the north-east angle of the bay.

92. One generally reaches this point late in the day, when the rays
of the declining sun already fall strongly on the outer part of the bay,
the upper portions being in the deep shadow of the high western
hills. The old castle on its raised bank of shingle, which has kept
its place steadfastly against wind and tide for at least 2,000 years,,
is a fine object in the foreground. The middle of the picture is
occupied by boats, in from the fishing, and by nets suspended
between high poles, beyond which is a line of white cottages on the
west side, and houses of higher pretensions on the east, from which
the curling smoke rises up invitingly. The background is a
dark circle of gloomy hills, now reflected in the lipping tide, which
give an air of peculiar solemnity and seclusion

" To the lone hamlet, which her inland bay
And circling mountains sever from the world."

Beyond, and over all, rises the serrated granite ridgo of Castle

134

Abhael and the Sui, gleaming now in the golden light of
sunset, and contrasting strongly with the dark slate hills of Ben-
Leven and Tornidneon, thrown into deeper shade by the high hills
on the west. The place altogether has a singularly picturesque and
unique aspect ; the stranger will say he has never seen such a
hamlet and bay before. Yet will he find most comfortable quarters
at the unpretending inn, and even luxuries not easily found elsewhere.

The stranger who has got but one night at his disposal to spend
in Loch Ranza, should contrive to reach the place so early that
he will have time for a stroll along the sea shore, to the west,
in the direction of Glen Catacol. Towards sunset, on a clear and
still summer evening, the scenery appears to the highest advantage.
It has then a quiet but touching beauty, which steals into the very soul.

There are several objects of much interest about Loch Ranza.
The castle is still in tolerable preservation, though now roofless. It
stands on a bank of shingle, running across the mouth of the bay,
and forming the harbour. We first find it mentioned as being a
bunting seat of the Scottish kings, in 1380 ; it was then reckoned
one of the royal castles. But the date at which it was erected is
not known. The Montgomeries of Skelmorlie, ancestors of the
Eglinton family, afterwards possessed it, with much of the north
end of the parish. They, however, lost the entire property, as an
unredeemed mortgage, to the Hamilton family (New Statist. Acct.,
vol. v.) The ruins of the Convent of St. Bride, which till lately
existed here, are now swept completely away. The only interest
connected with it lies in association with the well known scenes in
Scott's Lord of tJie Isles, in which the scenery of " fair Loch
Ranza" is very prettily and graphically described. The harbour is
the resort of fleets of fishing boats. It is a most picturesque and
exciting scene to witness the launching of these boats on a summer
evening, under a favouring wind. In rapid succession they drop
down from the harbour into the outer bay, and dart away in
bounding glee, some out north into Loch Fyne, and others away to
the left, across the broad waters of Kilbrannan sound. Though so
land-girt and safe looking, Loch Ranza is by no means a safe anchorage.
The most fearful squalls, sometimes even in summer, fall upon it
from the narrow opening of Glen Eis-na-vearraid, between Tornidneon
and Meal-Mhor. The currents of a S.E., S., or S.W. wind traverse
the whole length of this long glen, hemmed in between high hiUs,
and issue from the narrow gorge with terrible violence. Vessels are
thus often driven from their moorings, and obliged to seek safety in
the open frith, or by running for Loch Fyne.

135

The only object of great geological interest near Loch Ranza is
the granite junction at the base of Tornidneon. This bold and
finely-shaped mountain, about 1,500 feet in height, rises on the
east side of the gorge above referred to, through which a torrent
descends into the head of the loch, having cut a deep channel in the
solid rock. The place is wild and picturesque ; at some points
great caution must be used in selecting our footsteps. We are upon
the junction in the river bed, at the upper end of the gorge, where
the open glen begins. Many fine branching veins of granite run
into the slate, narrowing to threads as the distance increases, the
granular structure becoming at the same time more minute; some are
interstratified with the slate. As already noticed at the Glen Rosa
junction, the slate is banded with quartzose layers ; and these, as
well as the slate layers, are much contorted. In some of the
larger veins the granite is coarse-grained, but usually a more
compact or confusedly crystalline strip separates these from the
slate. The front of Tornidneon shows several fine veins and alterna-
tions where the two rocks approach, as already noticed in Art. 52.
The whole appearances are strongly confirmatory of the intrusive
character of the granite ; and this junction early became celebrated
in the discussions between the abettors of the igneous and aqueous
theories.

Some fine junctions may also be seen across the hill tops between
this point and Glen Catacol. We may ascend from here and return
from Catacol by the shore ; or first visit Catacol from Loch Ranza,
examine the terraced ridges at its mouth, and then ascend by the
granite junction at the N.E. angle of the glen. The descent upon
Loch Ranza from the high platform is not difficult. The walk
affords many grand views.

EXCURSIONS VI., VII., VIII.

93. THREE interesting excursions may be made from Loch Ranza,
from none of which, however, will it be easy to return to this
place on the same day. They may, therefore, be taken at different
times, after an interval. Most tourists will prefer the last — a return
to Corrie by the inland route.

A walk by the shore, from Loch Ranza to Dugarry, about
eleven miles, will more amply reward the lover of the lonely, the

136

wild, and picturesque, and the botanist, than it will the geologist.
Still there is the slate to study; the whole walk is upon slate ; and
the many changes in its mineral character, the effects of former sea
action upon it, as shown in the ancient cliff, which in some places
advances boldly on the shore, and in others retires inland, and as
compared with the like action on the sandstone, will form interesting
subjects of inquiry. Abrupt changes in dip will be noticed in the
slate, at the north side of Glen Catacol. With the exception of a few
singular inversions, due, probably, to dikes, it maintains a pretty
uniform dip and inclination, 40° E. of S. at about 40°, till we approach
Glen Catacol, north of which an anticlinal seems to occur, owing to
an advance of the granite in the direction of the bay. On one
side the slate rises up towards the granite, as if thrown off from it,
the dip being 65° W. of N. at 53°; on the other it dips E. and S.E.,
at about 30° to 40°. But this dip is not maintained ; it is some-
times directed towards the granite, in other places, " end on " to it,
or southward, and in others again off the nucleus, or nearly west;
but there is never exhibited that mantling stratification around the
nucleus which is usually seen in granite tracts.

It is only on this extreme north-western border of the slate tract
that the micaceous character which prevails in Cantire is assumed
by the slate. Near the Free Church, which stands on a lovely
picturesque spot in North Thundergay, a fine mica slate, banded
with quartz, occurs ; east of this there is much chlorite slate, and
one mile west of it, near the secluded burying-ground, blue argil-
laceous slate, mixed with the chloritic variety. But generally
there is on this side a greater tendency to the micaceous character.
On the Imochair shore, and towards Dugarry, the ordinary character
has become again established. — There are comparatively few dikes
on this coast. A little east of the Free Church there are two, each
of which appears to bifurcate. On the Penrioch shore a great bed
of greenstone, 100 feet broad, occurs. We did not notice a single
bed either of porphyry or claystone. Many boulders of granite
occur; northwards they are of the coarse-grained variety, but of
both varieties on the South Thundergay and Penrioch shores. A
few were estimated at as much as twenty to thirty tons weight.

As the coast from South Thundergay southward, is somewhat
monotonous, we would recommend the tourist, if the day be clear
and steady, and he has had an early start, to diverge inland at South
Thundergay, visit the lovely and secluded corrie and tarn, called
Corrie-an-Lachan (hollow of the lake), ascend Ben-Varen from the
north, pass along its eastern ridge, and descend upon lorsa water-

137

foot, through Glen Scaftigall. He will be delighted with the wild
scenery, and will notice many objects of geological interest.

The terraces already noticed (Art. 58) at the mouth of the lorsa,
in front of the Duke of Hamilton's shooting lodge, are very striking
— by far the most remarkable in Arran.

There is no hotel in this part of the island, but very comfortable
quarters can be had at a farm-house in the hamlet of Auchincar, a
short distance east of the lodge. The tourist can then easily find
his way to Brodick, or he may pass along the shore by Mauchrie
waterfoot to Tormore and King's Cove. Glen lorsa opens on this
part of the coast ; and here the number of granite boulders greatly
increases, the proportion being now in favour of the fine-grained
variety, which exists throughout the whole of Glen lorsa. From
lorsa waterfoot the coast section presents first old red sandstone
and conglomerate, and then carboniferous sandstones, but no junc-
tion is visible of the slate with the Old Red. We observed scratched
boulders about Auchincar.

94. A walk across the interior of the granite nucleus, from Loch
Banza to lorsa waterfoot, will be good work for a long summer
day ; or the geologist may return from Auchincar to Loch Ranza by
this route. We preferred the former, diverging westwards at the
base of Ben-Varen, ascending that mountain, and descending upon
Imochair, to reach Dugarry by the coast road.* In this way we
can visit the Tornidneon junction, pass up Glen Eis-na-vearraid,
by the burn, fully examine the two granites, visit the lakes (Art. 43,
p. 62), trace the dikes in the fine-grained granite (Art. 46), inspect
the great beds of china clay under Ben-Varen, to the N.W. of the
head of Loch Tanna, and either mount to the summit of Ben-Varen,
or pass on southwards by the base of Sal-halmidel to the mouth of
the lorsa. The botany of this part is meagre, but objects of geolo-
gical interest will be met with, allusion to which now would be
mere repetition of what has been already stated.

95. The inland route from Loch Eanza to Corrie presents a few
objects of interest. A walk of three miles by the high road, which
winds screw-like along the hill-sides, by the edges of the deep glens,
brings us to the summit of Glen Chalmidel, and the watershed into
north Glen Sannox. The views of the northern front of the ridge of
the Castles and the Sui are very grand from this point. A few
hundred yards below the summit, as we pass down into Glen Bhu,
granite appears by the road-side; and in the river bed, a little farther,

* By previous concert with friends at Brodick, a vehicle may be in waiting at
Dugarry. — Yery welcome it will be after so long a march.

T

138

a junction of the slate and granite is very well exposed. A glance
at the map will explain the occurrence of the granite here. The
principal junction is at the point where the river comes close in under
the bank, along which the road passes. Here there are some pecu-
liarities well worthy of notice. The two rocks are seen to come
close up against one another, 'most distinctly contrasted ; but there
are no veins emanating from the granite. This rock is coarse-grained,
much coarser than in any other junction we have noticed, yet it is
more compact than the coarse-grained granite usually is, and, though
hard, brittle. About one hundred yards down the stream a vein
of fine compact granite, five feet broad, traverses the slate ; and thirty
yards farther, another vein, one foot broad, bluish coloured, fine-
grained, and very brittle. The entire mass of slate, between this
lowest vein and the mam junction above, is much altered; it is
extremely hard and tough, contorted in the laminae, and being much
veined with quartz, is assimilated in aspect to a granitic rock.
Below the lowest vein it speedily assumes its usual appearance. Mr.
Ramsay was the first to notice this interesting junction; and it is
well described by him. Several other junctions may be seen in
the branches of the main stream.

A little farther down the glen, and less than one mile from the
bridge, some well marked glacial striae are seen on the road-side, upon
a mass of slate in situ. They cross the laminae, and are directed
nearly due east and west. The slate also is rounded off. — On the
hill to the north, some great blocks of coarse granite rest upon the
slate. These travelled blocks reach a good way up the south front
of the coast range; but in crossing, on one occasion, along the
summit, keeping generally near the edge of the cliffs, we did not find
a single block. It would seem, therefore, that the few, and com-
paratively small blocks, on the north shore, must have worked
round, from either side, under the force of the waves. Slate was
found everywhere on the summit, and far down upon the steep fronts,
where the junctions take place. — Some curious varieties of slate will
be observed in the river bed, on both sides of the bridge. A short
distance below the bridge, we leave the slate, and, after an interval,
come on coarse conglomerate, no junction being visible.

Many years ago, a large population, the largest then collected in
any one spot in Arran, inhabited this glen, and gained a scanty subsis-
tence by fishing, and by cultivating fertile plots on the sunny hill-sides.
Forty or fifty years ago they were obliged to leave, and furnished with
the means of reaching Canada. Garden enclosures, and ruined wall-
steads, still remaining, give a melancholy interest to this secluded glen.

139

Near the summit level of the road between north and south
Sannox, arid a little to the north of Sannox house, the sandstone
strata, on the east side of the road, are marked with striae, rendered
somewhat fainter than those on the slate by the effect of decompo-
sition. Like these they are transverse to the laminae, and are
directed 5° S. of W. (70° W. of magnetic N.), that is, in the
direction of the ridge of Suithi-Fergus. If we assign their origin
to ice, then we must admit that the moving masses advanced in parallel
courses, in both cases, from high ground on the west.

We are now within a few yards of the spot where the finest view
of Glen Sannox is obtained, and to which a former excursion brought
us. Taking another survey of the grand scene in its evening aspects,
we press forward to Corrie, to catch the Clyde steamer on her way
to Brodick.

EXCURSION IX.
To HOLT ISLE.

96. MAKE choice of a day when it is high water about noon, and
leave Invercloy for Lamlash by the mail steamer from Ardrossan.
The captain, whose polite attention to all visitors is well known,
will land you at the wooden pier on Holy Isle, and on reaching
Lamlash, will order a boat to fetch you to the mainland at any
given time. A few hours will suffice to examine the island and
ascend the mountain. The basis of the isle all round is sandstone,
which rises to the height of 100 to 150 feet ; the rest of the moun-
tain, to the height of 1,020 feet, is composed of claystone, so that
this rock has the thickness of about 850 or 900 feet. On part of
the east side, however, it is much less than this, as the sandstone rises
there much above its usual height. The rock is of igneous origin, a
member of the trap family, and varies in structure from a soft clay-
stone to a compact felspar ; the harder varieties are called clinkstone.
As in most traps, the prevailing form is prismatic ; and on the
E. and S.E. sides of the island, columns of great length appear in
the high precipices. But the schistose structure is also common ;
and, as in cases already mentioned at Corriegills, both structures
occur in the same mass, the slaty fracture being at right angles to
the axis of the prisms ; the ends of the prisms first divide into
laminae, and the mass gradually assumes the slaty structure. The

140

weathering of the rock is remarkable, and extends to a considerable
depth, presenting successive concentric zones of different colours,
which have a very pretty appearance in many specimens. The
slaty structure itself, in the case of this rock, seems to be but a step
in the process of decomposition.

Various masses of greenstone occur, both as dikes and beds ; one
on the S.E. side presents remarkable alternations with the sandstone,
and alters its structure. The felspar rock itself is seen in one place
on the east side to intersect the whole body of strata, and to be
connected above with the overlying mass of the same rock. Here,
also, there is a very interesting vertical vein or dike, intersecting
an oblique trap vein, and showing in the centre fine black basalt,
containing zeolites and glassy felspar ; on each side of this there is a
lamina of a black substance, intermediate between basalt and pitch-
stone, and at the outer surfaces a coating of vitreous pitchstone one-
tenth of an inch in thickness. These substances, indeed, are all
of one origin, the variations found here, as well as in other places,
being due merely to different rates of cooling in the once fused mass.
The same oblique vein is intersected by a vertical vein of concre-
tionary trap. Dr. MacCulloch gives a drawing representing the
appearances (West Isl., vol. iii., pi. xxiv., fig. 2).

The granite blocks on this island have been already noticed
(Art. 59). On the west side, near the landing, there is a raised
beach or shelly deposit thirty feet above the present sea level. Adders
abound upon the island, but their number is said to be diminishing.

97. The tourist must visit the hermitage of St. Molios. It is
situated a mile south of the landing place, and is a natural excavation
in the old sea cliff. The folio whig is the correct legend of St. Molios.
The conjectural account usually given is quite inaccurate : — " The
legend of St. Lasrian, or Molassus, is well known to Irish antiquaries ;
it was printed in the Bollandists' collection, Acta Sanctorum. He was
born in Ireland A.D. 566, educated in Bute by his uncle, St. Blaan,
returned for some years to Ireland, and afterwards, when yet only
twenty years of age, retired to an island in Scotland, where for some
years he led the life of a hermit — probably in the cave which is still
pointed out as his in Lamlash Isle, i. e., ' Isle-a-Molass,'* later
named the ' Holy Isle.' About the year 614 he was elected Abbot of
Leighlin, in Ireland, and was afterwards made a bishop, and Apos-
tolic legate to the Church in Ireland. He died in the year 640.

* Lasrian and Molassus are radically the same. "Las," meaning "light," was
probably the proper name; the prefix "mo," and affix "rian," mean "very" and
" good," expressing approval or endearment.

141

The inscription on the roof, in Eunic letters, has no reference to
Molassns. The words, 'Nicolas hann raisti' — ' Nicolas this engraved'
— are Norse or Icelandic, and clearly refer to a Norwegian hermit who
resided here at the time when the Northmen ruled the Western Isles,
or ahont A.D. 1100. Wilson (Arch, of Scotl., p. 531) identifies this
hermit with a bishop of Man. He would make the inscription refer
to the excavation of the rock. But this has clearly been the work
of the sea ; and, besides, the cave was the abode of St. Molassus
at an earlier period. Mr. Wilson gives some other fragmentary
Runes. A small cell or monastery was erected in connection with the
hermitage, apparently by Reginald de Insulis, between 1206 and 1212,
probably in connection with the monastery of Saddell, in Cantire,
founded by him, and to which he granted lands in Arran. It seems
to have been an abbot of this small monastery, whose tombstone,
bearing his chalice and pastoral staff, but without any inscription, is
still extant in the ruins of the ancient burying place and chapel at
Clachan glen, and which is popularly called St. Molios' grave."* The
traces of this monastery were till lately to be seen north of the cave,
beside a burying-ground, which was long used as the chief place of
sepulture for Arran, till the loss of life by the upsetting of a boat
led to a discontinuance of the practice. — A pure spring of water close
by the cave, was long famous for supposed healing qualities.

EXCURSION X.
To WINDMILL HILL AKD PLOVEBFIELD.

98. THE Windmill hill is conspicuous from all parts of the
Brodick coast, as the high narrow crest of a long ridge which divides
Glen Shirag from Glen Cloy. It may be readily ascended from any
side. If we pass along its north front from the String road, we
shall see the pits from which shell limestone, like that at the Chapel
of Ease, was formerly quarried ; but the ascent along the south-
eastern front will best expose to our view the structure of the hill.
We pass up the lovely banks of the Cloy burn, fragrant all the way
with blossoms of the choicest wild-flowers, till we reach the bridge
leading to the old mansion of Kilmichael. This is the seat of
the Fullarton family, proprietors of an estate here — the only por-

* This corrected legend has been kindly made known to me by John Mackinlay,
Esq., of Bonnington.

142

tion of the island not possessed by the princely house of Hamilton.
The Statistical Account informs us that the grant of the lands of
Kilmichael was made by King Robert Bruce for services rendered
by an ancestor of the Fullarton family, called MacLuoy or MacLewis
— a name only now preserved in the designation of the glen. But
this statement is not correct: Bruce had no lands in Arran to
bestow, the whole island, except some church property, then
belonging to the Stewart family. The grant was made by King
Robert III., who belonged to this family, about the year 1391 ;
and the charter then given is still extant. The Hamilton family
acquired the greater part of the island by marriage in 1474. Arran,
erected into an earldom a short time before, was given as dowry with
the Lady Mary, sister of James III., on her marriage with the Lord
Hamilton.

The front of Windmill hill is formed, through about half its
height, of columnar felspar porphyry, similar to that of Dun-Dhu,
already described (Art. 77). The columns are four, five, and six-
sided, with flat jointings ; the pillars lean in various directions. The
junction with the sandstone below is nowhere visible. About the
middle of the front of the hill, a mass of altered sandstone, 12
feet wide, is imbedded in the porphyry. Close to this is a whin
dike, running 10° N. of E. Several others traverse the ridge of
porphyry — another example of the posteriority of the common trap
or whinstone to all the rocks of Arran. The plane of contact
between the sandstone and porphyry gradually ascends westward,
and, on reaching the S.W. shoulder of the hill, we find a wedge-
shaped mass of sandstone connected with the body of this rock
below, and apparently separating the porphyry from the granite
which immediately succeeds. No true contact of these rocks is
observable. Sandstone, slaty pieces of porphyry, granite sand, and
bits of granite are seen lying about, mixed up confusedly, and no
line of demarcation can be laid down. Presently the hill-side shows
granite only. Eastwards all the high ridge of Windmill hill is
porphyry; sandstone is seen at the north base, but no contact is
visible. The base of the porphyry is an intimate mixture of felspar
and quartz, of a gray or bluish-gray colour, with imbedded felspar
crystals, bits of quartz, and occasionally well formed crystals of this
substance. We have already (Art. 50) described at sufficient length
the relations of the sandstone to the Ploverfield granite, to this
porphyry, and the syenite of the hill-sides westwards, into which
the granite seems to shade off; and need not now recapitulate. The
series forms an interesting study. The granite, porphyry, and syenite,

143

are all posterior to the sandstone ; but we have as yet no means of
knowing the age of the porphyry in relation to the granite. The
common greenstone of the dikes, and detached knolls upon the
plateau southwards, is the newest of all these igneous products.
Sir C. Lyell, following Prof. Ramsay, remarks on "the overlying
trap ceasing here very abruptly on approaching the boundary of the
great hypogene region, and terminating in a steep escarpment facing
towards it as at 5 /, fig. 702, p. 591. When in its original fluid
state it could not have come thus suddenly to an end, but
must have filled up the hollow now separating it from the hypo-
gene rocks, had such a hollow then existed" (El., edit. 1855,
p. 592). By this "overlying trap" is meant the common trap of
the southern plateau, as is seen by referring to Ramsay's section,
copied by Lyell; but there is no such rock here. The porphyry is
the only erupted rock, and its occurrence in this sharp-crested hill
must be explained as we explain the existence of granite in moun-
tain peaks, or basaltic lavas in the mural precipices of Mull, and the
Giant's Causeway. There is no igneous rock of any kind " at the
points 5 ft" overlapping the carboniferous sandstones and resting on
the old red sandstone (see Art. 46, sub. Jin.)

99. Passing round the heads of Glen Dhu and Glen Cloy (Art. 50),
we come over the edge of high sandstone cliffs bounding Glen Cloy
on the south. On a grassy ledge under the western part of these
cliffs there occur two remarkable dikes, producing a highly interesting
change upon the sandstone. A large body of this rock, between the
two dikes, is altered to the state almost of quartz rock, and beautiful
crystals of amethyst are developed in it ; quartz crystals, both
colourless and with a slight tinge of yellow, also occur. The dike
on the S.E. side is a brick-red porphyry, resembling that on the
Corriegills shore; it appears also in the cliffs above, where, by wearing,
a fissure is formed upon it ; the dike on the N. W. side is of green-
stone. There is a third dike or mass of trap outside the porphyry;
but neither its relation to the others, nor of these to another, can be
well made out. The locality altogether is fully as interesting as
any in the island. The isolated high round knolls, called the Sheeans,
over the head of Glen Cloy, are trap. Passing from them to the
head of Lamlash or Bein-Leister glen, we meet with a few low
knolls of like composition, but no body of overlying trap. Lamlash
glen affords a fine section of the carboniferous series : red] limestone
and red marl at the top of the glen, and lower down two other
considerable beds of limestone, the last being about a mile and a-half
from Lamlash. They contain the usual fossils, and occur amid

144

massive sandstones. A short distance below the lowest limestone,
a dike of felspar rock, or quartziferous porphyry, fifteen to twenty
feet wide, crosses the bed of the river, ranging nearly N. and S.
The sandstone is greatly altered by it. Between this point and the
alluvial plain there are several veins or beds of clay stone and greenstone,
breaking through the sandstone of the river bed. — In the village of
Lamlash we may pay a visit to John Allen, the only collector of mine-
rals and fossils that we know of in Arran, and engage his services for
an excursion to Ceim-na-Cailliach.

EXCURSION XI.

To CEIM-NA-CAILLIACH AND THE CASTLES.

100. EXCFBSIONS in Arran may be varied indefinitely according to
the taste and objects of the tourist or student. We have indicated
a few best fitted to show the geological features of the island ; and
as we have now described the different formations and the most
remarkable appearances which they exhibit, we shall only mention
shortly the chief remaining objects of interest which in other excur-
sions might be visited.

The principal object in our present excursion will be to look for
" the black crystals," as the smoke-quartz crystals are called. Their
chief repository is the north side of the Suithi-Fergus ridge, and
that of the Castles. They are found in the coarse-grained and
rapidly disintegrating granite of the great northern ridge. Allen
knows their localities, and is often successful in collecting them. We
pass up by the N.E. angle of Glen Sannox, and then diagonally along
the back of the ridge.

Ceim-na-Cailliach, or the Carlins' Step, is an immense chasm or
gash in the ridge, overlooked by granite walls several hundred feet
in height. The interior of the fissure can be easily reached by
entering laterally at a pretty low level on the north side. We find
it to be merely a whin dike worn down to this great depth below
the containing granite. The rock is a dark coloured fine-grained
greenstone of loose texture ; it exhibits the concentric spheroidal
structure so often alluded to as characteristic of common whinstone.
There is no trace of any other rock ; and we cannot understand how
it has come to be so often said that this dike is pitchstone. The

145

dike and chasm pass down into Glen Sannox, but it is impossible to
descend by this way. The view is very wild and grand. When
the morning mists are hovering around Goatfell, and rolling into
the depths of Glen Sannox, now hiding and now revealing the
mountain with the ridges and peaks adjoining, the scene from
the summit of Castle Abhael is extremely grand. — Various ways are
open for us by which to return. We were once surprised here by a
thick fog with heavy rain, and guided partly by a compass, and
partly by keeping as close as possible to the junction of the coarse
and fine granite, we found our way safely along the edge of the
great circular ridge which runs from the N. W. base of Castle Abhael,
in the direction of Glen Dhu, at the upper part of North Sannox.
But the convenience of our companion, with his load of "black
crystals," must now be consulted in regard to our homeward route.

EXCURSION XII.
GLEN SANNOX AND GLEN Eos A.

101. This is a favourite excursion with visitors to Arran ; many
will devote a day to it in preference to others which are less easily
taken from Brodick as a centre. But there are comparatively few
objects of geological interest, and we shall not therefore enter into
any detailed description.

There is an interesting old burying-ground at the entrance of Glen
Sannox. It is all that remains of a church or monastery dedicated
to St. Michael. A rude image of the saint is to be seen upon a
stone built into the wall. The house was probably connected with
the Abbey of Kilwinning, to which Sir John Monteith, Lord of
Arran, granted, in 1397, the lands of Sannox and patronage of the
churches. The barytes mill sadly mars the solitary grandeur of
the scene which opens as we reach the plateau at the mouth of the
glen. It was erected here some years ago to work veins of the
sulphate of barytes, or heavy spar, which traverse the old red sand-
stone. These are seen in the bed of the stream, running in a
direction nearly N.E. and S.W., and dipping nearly N.W. ; they
appear also on the hill-side southward. The junction in this burn
has been noted already. By the bank of this fine stream of crystal
water, rushing over its bed of granite sheets and granite sand, amid

u

146

huge rolled masses of the rock, is a delightful walk. Near the head
of the glen we may diverge a little to the right, and examine, at
this lower level, the dike and great chasm descending from Ceim-
na-Cailliach. Following it southward on its line of bearing we trace
it entering the granite precipices in front of the hase of Cior-Mhor,
and passing on over the col, in the direction of the axis of Glen Rosa.
The safest pass into this glen is at the western side of the col, or
ridge joining Cior-Mhor to the hase of Goatfell. In the hollow up
which we pass we have a whin dike beneath our feet, and granite
walls on either hand — the pathway, in fact, has been formed by the
disintegration of this dike. On reaching the summit we observe a
great dike, most probably a continuation of this one, ranging right up
the front of Cior-Mhor. When one reflects upon the mode of origin
of these two rocks, granite and greenstone, it strikes one with
wonder to perceive the curious relations which they maintain, and
the important part in the physical condition of the region which the
dikes play. M. Necker goes so far as to suppose it quite possible
that the excavation of Glen Rosa may have been determined by the
great dike above noticed. In the lower part of the glen the river
runs upon it, between high granite walls, for a long distance
(Arts. 64, 65). It is thus by far the most continuous dike yet traced
in Arran.

M. Necker describes a very curious dike as existing on the ridge
between the two glens, which we were not so fortunate as to notice
in any of our walks this way. " It passes along the ridge between
the glens, on the S.E. side of Cior-Mhor, ranging nearly east and
west. It consists of five bands; in the middle, there is green
pitch stone, on each side of this a band of clay stone porphyry, two
feet broad, beyond which are two bands of common trap seven and
a-half feet broad each. The dike forms a deep ravine, which
reaches to the summit of the mountain. The claystone disappears
aloft, and the pitchstone is then five feet broad, and each band
of trap four feet ; the band on the north side shows the spheroidal
decomposition." — (p. 693 of Mem., quoted p. 83.) We noticed no
dike on the summit, nor upon the S.W. and western sides ; but
it is quite possible it may exist there.

There is little else of much interest in Glen Rosa; the
granite junction has been described already in our first Excursion
(Art. 64), and the singular chasm just noticed will be seen as we
pass along. The adder (Pelias berus) is often met with in the
glen, in places where there is a dry bottom under the heather; and
the tourist in crossing these will do well to use caution. Again

147

and again we have narrowly escaped treading upon them in such
situations, here, in N. Sannox, in Lamlash Glen, and other places.
We have never seen them higher, however, than about 1,000 feet ;
nor are they as abundant on the west as on the east side of
the island. They occur also in Holy Isle. A long and interesting
account of the creature, with figures, will be found in Bell's British
Reptiles (p. 61-75). It is the only British representative of the
poisonous group of serpents; but there is no authenticated case
of fatal effects resulting from its bite in Arran or elsewhere in
Britain. We have heard of more than one case of severe symp-
toms; but these were removed in a few days by an application of
herbs boiled in butter.

The burns of Arran are all beautiful and picturesque, but in
different styles, according to the nature of the rocks across which
their courses lie, Those of the granite and slate tract are the most
beautiful ; and this Rosa burn, especially in its lower course, and
after it enters Glenshant, far surpasses in romantic beauty all the
bright streams of this lovely island.

102. Over the wood which covers the eastern end of the ridge on
the south side of Glen Rosa a curious meteorological phenomenon
is often witnessed. When the wind is at S.W. or W. with a damp
and warm atmosphere, a column of vapour is seen ascending from
near the centre of the wood, remaining in a nearly steadfast position
for some time, and then suddenly vanishing ; to be again formed, and
again as suddenly disappear; and this is repeated through a period
sometimes of several hours. The explanation, no doubt, is that
currents of wind descending Glen Shirag on one side, and Glen Rosa
on the other, produce, by the rapid out-draught into Glenshant,
a partial vacuum and vortex of light ascending air over the middle
of the wood, which is completely sheltered; and by this reh'ef of
pressure a condensation of vapour takes place, just as a cloud is
formed in the exhausted receiver of an air-pump.

We may mention now, when on the subject of meteorology, an
interesting case illustrating the relations in which the different
kinds of clouds stand to one another: — On a bright hot day, after
rain on the day previous, a pretty rapid current of wind from
W.S.W., with scattered masses of white fleecy clouds, prevailed aloft
from early morning as a land wind ; while a light east wind blew
below as a sea breeze. The currents met, a little way out in the
channel, off the Corriegills shore ; and along a strip of sky, stretch-
ing from north to south, the fleecy cumuli of the S.W. current
were arrested by the current from the east, and resolved into a

148

broad band of cirri. By four o'clock in the afternoon the upper
current had descended to the surface ; and a strong breeze from the
west, preceded by a whirlwind, immediately sprang up. Towards
evening this gradually subsided into a gentle air. — The day was one
of those delightful Sabbaths to be enjoyed only in the rural districts
of Scotland, or the North of Ireland. The Free Church congre-
gation of Brodick was observing the communion services; and a
vast concourse of pious and most attentive worshippers was assembled
from all parts of the island ; one minister officiated in English in the
church, while another conducted the service in Gaelic from a tent
in the open field. Apart altogether from the solemn feelings
awakened by the simple and touching service, the mere picturesque
adjuncts of these scenes at Brodick will never fade from the memory
of any one who has witnessed them.

MEMORANDA OF OTHER EXCURSIONS.

103. To King's Cove is a favourite excursion, and deservedly so,
for the scenery there and about Drumadoon is extremely beautiful.
With this may be combined a visit to the Craig-Dhu granite and
the Tormore pitchstone dikes. The druidical circles at Tormore
should also be visited. But all this is too much work for one day.
In returning to Invercloy on foot from King's Cove or Tormore,
the walk will be varied by striking off the main road at
Shiskin, and crossing right over the island in the line of Clachan
Glen, and descending from the high plateau above Ploverfield, either
by the Windmill hill or the Sheeans. To walk from Invercloy by
Mauchrie waterfoot and Tormore, and return by this route, is no
mean performance for one day. But the platform ought to be
gained before sunset, as twilight falls rapidly in Glen Cloy, and the
ground between the Sheeans and Invercloy is broken and difficult.

THE STEIK& ROAD. — After the watershed is passed granite ap-
paars on our left hand, and runs a long way down the glen of
the Mauchrie; then bands of the syenites from the plateau region
strike in upon the road, intermingled with the sandstone. The Glen
Luigh limestone will be found farther on, high on the southern hill-
side, by following a bridle road leading to the old quarry. It is a
crystalline lime without fossils, much altered by the trap veins
which traverse it. It is in the same position as the lime at Achab
farm (Art. 87), and the Fallen Rocks.

149

CRAIG-DHIT. — The Craig-Dim granite has been fully described
already (Art. 51). Craig-Dhu is a high steep cliff fronting that
part of the Shiskin road where the road to Dugarry parts off from
it. A talus of blocks strews its base. We noticed, from a distance,
in driving along the road with a party of friends in July, 1855, how
unlike these were to sandstone blocks, and were thus led to the
discovery of the granite tract. It struck us as remarkable, that,
on a route so frequented, the occurrence of the granite here had
so long remained unnoticed.

CLACHAN GTLEN. — The upper beds of the Old Red rise into the
lower part of this glen; the middle and higher parts show the
lower and middle beds of the carboniferous system, which pass over
the watershed towards Lamlash. High on the south side of the
glen, apparently by an upthrow of the strata, beds of white lime-
stone with quartz pebbles, like that of Aehab farm and the Fallen
Rocks, are brought to the surface. The metamorphic action
towards the head of the glen is the most extensive and remarkable
which we have seen in Arran. All the ordinary characters of the
sedimentary strata are obliterated.

TRAVELLED BLOCKS. — Leaving the Shiskin road and taking
that to Dugarry in order to reach Mauchrie waterfoot, we are cross-
ing in front of the fine-grained granite tract of Glen lorsa; and
accordingly we find that here the great proportion of the boulders
are of this variety of granite ; while those on the eastern side and
along the south plateau, are of the coarse variety. This points
to a cause locally acting in the direction of the glens ; — we never
find lorsa granite on the east side of the island; both kinds are
mingled on the west side (see Art. 60).

THE TOEMORE PITCHSTOITES. — We cross from the Dugarry road
by the mouth of the Mauchrie to reach Tormore. Less than a mile to
the south, in front of the sandstone cliffs of King's Hill, there occurs
the finest set of dikes to be seen in Arran, exhibiting, in a small
space, all the members of the igneous series, greenstone and basalt,
porphyry and trap porphyry, pitchstone, claystone, and hornstone.
To understand the relations of the various dikes, the shore should
first be traversed several times, the whole extent being only a few
hundred yards. The sandstone platform is bounded southward by
the sea, and by a mural precipice sixty feet high, along the base of
which there is no passage southwards, except at low water. This
precipice is the western front of an immense dike of felspar por-
phyry, eighty to ninety feet wide, ranging a few degrees N. of E.,
and here taking the place of the sandstone in the cliff for a con-

150

siderable distance. Placed longitudinally in this dike, westward of
its middle part, there is a greenstone dike about four feet wide,
running out with it seaward to the low point where the porphyry-
dips into the water; it is also crossed diagonally by a greenstone
dike, which bifurcates upon it, and is seen far up on the hill-side
above. Alongside the dike there is a pretty large cave. The
pitchstone and other dikes traverse the sandstone platform to the
north of this. The principal dike, traceable continuously for a
long distance, is formed of green pitchstone; it rises from the sea
southward with a range 40° E. of N., a width of ten or twelve feet,
and a S.E. inclination of nearly 30°; but the course undulates 35°
or 45°, bending towards the west, or into parallelism with the shore,
towards its northern termination. There are veins of slaty horn-
stone on both sides, next the sandstone, and on one side a thin layer
of basalt. On the side of the great vein next the sea, numerous
veins enter it nearly at right angles. First, a vein of hornstone
six to eight inches wide ; next, one of basalt five feet wide. Another
vein running a little N. of W. has on its north side three
feet of pitchstone, passing into hornstone, then four to six inches
of clay stone, and on the south side fifteen feet of basalt or
fine greenstone. Next is one thirty feet wide running 35° W.
of N., consisting of basalt four feet; claystone fifteen feet; basalt
again six feet, containing a pitchstone vein along its middle part ;
lastly, a vein of greenstone five feet wide. There is here also
a vein of trap porphyry four feet wide: this and the others
intersect the pitchstone vein, but the intersection is obscured
by debris. The last vein northwards, is one of pitchstone with
hornstone and jaspery quartzite, running oblique to the shore, and
varying from eleven or twelve to thirty feet. Just outside the
tideway it meets and enters the great pitchstone vein, which, in its
sweep north, has reached this point, ranging now 10° E. of N.,
and at the junction there is nothing visible but claystone, which
forms the flooring at the common point of union. The great
vein stops here ; but that we are now noticing continues its course
under masses of sandstone, but is not seen in the cliff aloft, nor can
it exist there. Still farther north we noticed a pitchstone vein
running E.N.E., seven to ten feet wide, and visible in the cliff
above; but apparently in no way connected with the other veins.
The close association of so many igneous rocks is extremely
curious; we can hardly suppose the various products to be other
than cotemporaneous ; so that different rates of cooling and varying
chemical composition must have produced the differences now

151

observable. Professor Jameson was the first to describe this
interesting locality, which he does with great fullness and accuracy.
He gives also a figure illustrating the position of the secondary or
cross veins (Min. of Scot. Isl., vol. i., pp. 17 and 102).

KING'S COTE — is named from King Robert Bruce having landed
here from Eathlin in 1307, and remained a short time, according to
a tradition which there is no reason to doubt. The caves are in
soft yellow sandstone, and are the most capacious in the island.
Certain characters upon the roof seem mere unmeaning scratches,
— no one at least has yet deciphered them. In the bay south of the
caves, veins of pitchstone are seen in the cliffs, altering the structure
of the sandstone. On the summit of King's Hill, over the great
porphyry dike, noticed in the last Art., we observed many granite
boulders, chiefly of the fine variety. Among these one block was
most distinctly marked with glacial striae.

DETJMADOON. — Approaching this grand fa$ade of columns we
find on the shore a great dike of pitchstone porphyry tilting up the
sandstone at a high angle ; but its extension is not traceable. The
columnar range of Drumadoon, eighty feet in height, is composed of
a similar porphyry, almost exactly the same in structure as that
already described on the east coast (Art. 77). The pillars rest on a
laminar stratum, consisting of the base of the porphyry without the
crystals, and resembling a clay stone or metamorphic sandstone.
South of this there are some fine dikes. The coast scenery here is
most beautiful, and will bear comparison with any other in the
island. The botany of the sands is rich. On the summit of the
cliffs there are remains of extensive fortifications and rude dwellings,
the history of which is unknown. It has been conjectured that
these works, and those of a similar kind at Torcastle, near
Slaodridh, which are the only remains of the kind on the west
coast, were erected as a defence against an Irish invasion from
Cantire about the beginning of the sixth century; and that those
of the east coast, to the most remarkable of which, Dun-fion, we
have already alluded, probably existed before the Roman invasion,
when the Damnii, tribes of the mainland of Ayrshire, were at hostile
feud with the Epidii of the island and the opposite coast of Argyll.
See a paper by Mr. Mc Arthur, of Partick, in Ed. New Phil. Jour.,
vol. ix., Jan., 1859.

BLACK- WATEE-FOOT. — There are here numerous dikes of green-
stone, and a great bed of hard claystone, which upturns the ends of
the sandstone strata where they abut against it. In some places
the sandstone is greatly altered. The curved bands of claystone at

152

this place are illustrated by a drawing in Dr. MacCulloch's work
(pi. xxiv., fig. 3).

THE TORMORE CIRCLES. — The stone circles at Tormore, N.E. of
King's Hill, are the most complete in Arran; eight circles can be
traced, each consisting of from four to fourteen stones, which
measure from three to eight feet, and are six to eleven in circum-
ference; the circles have diameters varying from fifteen to thirty
feet. One of the stones has a perforation evidently artificial. The
stones are of the same kind of rock as the Brodick pillar. (See the
remarks in Art. 62). Various conjectures have been framed regard-
ing the origin and use of these circles ; some consider them as places
of druidical worship; others as sepulchral monuments. The question
is fully discussed in Wilson's Archaeology, as also the probable
origin of the single upright stones. Mr. M' Arthur, who has
recently examined these remains in Arran, with great care adopts
the latter view, which he supports by the following consider-
ations : — First, their occasionally enclosing a cromlech, undoubtedly
sepulchral; second, the discovery of urns, with bones and ashes
near them; and third, their cairn-like construction. He contends
that their resemblance to the enclosed British barrow is complete
(paper quoted above). Stone coffins with bones, and hollowed
stones, are also found; of the purpose of these there can be no
doubt. Sepulchral tumuli exist in many places, as at Black- Water-
foot and in Glen Cloy.

LEAOA-BREAC. — A walk in the late afternoon from Black-Water-
foot across Leac-a-breac to Lag, a secluded delightful spot, forms a
pleasant close to the excursion to King's Cove. Leac-a-breac is a
high hill with steep seaward front and long inland extension. It is
composed of felspar porphyry — the largest mass in the island. The
rock is well adapted for ornamental purposes. Sandstones and shales
emerge from under Leac-a-breac eastwards, and occupy the shore to
Benan-head, traversed by vast numbers of dikes, a group of which is
noted along the coast as forming the small safe port of South-end.

SLAODRIDH WATER — shows in its lower part, at and north of the
road, a great outburst of felspar porphyry in the bed and banks. It
is similar to the porphyry of Leac-a-breac, but apparently uncon-
nected with it. This rock, with syenite, greenstone, and claystone,
forms much of the hill-sides on the east of the river. The bed
and banks are occupied by shales and sandstones, among which a
careful search would, no doubt, be rewarded with the discovery of
many fossils. A walk from Lag, along this hill-side to Lamlash,
forms a pleasant and instructive excursion.

153

LAG AND BENAN-HEAD.— -We refer in another place to the
inducements which Lag offers as a centre for several excursions.
Many interesting appearances may be noticed in the vicinity, and
in the river banks near, some remarkable dikes. Benan-head
is a mass of igneous products, irregularly intermingled, so that
the relations of the rocks cannot be well determined. Dark-
based felspar porphyry seems disposed in alternate bands with
greenstone and basalt, the porphyry prevailing upwards, and the
two other rocks in the lower parts. Dikes of newer age intersect
the whole series. The entire mass of the headland is wedge-
shaped, narrowing downwards, the upper edge being on the same
level with the strata of sandstone on either side. The ends of these
strata abut against the trap throughout. On the beach westwards
there is a dike of red quartziferous porphyry.

These trap rocks range over the high grounds northwards ; the
coast section, as far as Dippen, presenting generally sandstones and
marls. The glens inland show similar sections, there being much
marl like that in Bein-Leister glen at Lamlash ; but we did not
notice any limestone.

DIPPED. — On the road towards Dippen, east of Auchinhew farm,
a stream descends over a pretty fall, seventy feet high, called Eis-
a-Mhor, into a large open basin, the perpendicular sides of which
present a facade of pillars resting on sandstone ; over this is another
bed of sandstone, supporting beds of amorphous trap. Dikes
traverse the whole series. The map will show the relations of
the rocks here — which, all the way round to Whiting Bay,
strikingly illustrate the intrusive character of trap, and in some
places the connection of dikes and overlying masses. There are
fine columnar trap ranges about Dippen, and a causeway on the
platform of the beach. Kildonan old castle stands on a great bed
or dike of trap, continued a little below the level of the water, as far
as Pladda island, which is thus attached to the mainland. The
island consists of a peculiar greenstone, resting on sandstone.
The Duke of Hamilton has lately erected a handsome shooting
lodge on a commanding site above the Dippen cliffs. Kildonan
castle is an old ruinous square keep, " one of a line of watch-towers,
reaching from the mouth of the Clyde to Dumbarton rock. It was
originally the residence of a family called Macdonald, who owned
lands adjoining. It next passed with the property, by purchase,
into the hands of the Stewarts of Kilquheelly, in Bute ; by them it
was sold with the rest of their property to the Marquis of Bute,

from whom it was lately purchased by the Duke of Hamilton."
— (New Stat. Acct., "Bute," p. 55, 1840).

WHITING BAT. — The sandstone of the shore is traversed here by
numerous dikes, and strewed with granite boulders of the coarse
variety, of which one is larger than any south of Brodick, with the
exception of the great Corriegills boulder. The relation of the trap
and sandstone are finely exhibited in Glen Eisdale. At the head of
this glen is the finest waterfall in the island ; on the brow of the
hill west of the fall, and near the side of the cart-road, we noticed,
upon slabs of greenstone, some well marked glacial striae, directed
nearly east and west. At King's Cross point there is a broad
bed of columnar basalt in the sandstone, the heads of the columns
forming a pavement upon the shore. Between Lamlash and Clach-
land point there are numerous dikes, some of which stand out more
boldly from the terraced surface of the old sea-beach than any dikes
in Arran.

MOKEADH-MHOB GLEN. — At the opening of this glen, in the bed
and banks of the stream, and of the lead of water connected with the
large mill adjoining, there are two great beds of pitchstone. They
are finely exposed, and exhibit very strikingly those transitional
phenomena already alluded to as marking the relations of this rock
to hornstone and claystone.

Associated with the pitchstones there are claystones, hornstones,
quartz rock, and porcellanite. Hornstone, that is, chalcedonic or
jaspery chert, seems to be the link between pitchstone and claystone.
Hornstone and pitchstone are both almost entirely siliceous ; the
difference consisting in the colour and degree of toughness arising
from a slight change in composition, or variation in the rate at
which they cooled, or from both. By this change pitchstone passes
into hornstone. In this hornstone a great many light-coloured
spots with dark centres are gradually developed; and bands of this
variety succeed the common hornstone. Next to this there follows
a hard quartzose claystone, and the series terminates in the common
claystone of open texture, like that of the Corriegills shore already
described. The spots or specks are minute spheres, most probably
of felspar or quartz, or of both, and have probably originated in the
manner suggested at the end of Art. 75. They present a close
analogy with the spherulitic claystone of Corriegills; but the
radiated structure of the latter does not exist here. Even the
larger spherules of the pisolitic hornstones do not exhibit this
structure. The quartz rock at the upper end of the higher pitch-

155

stoue vein is probably only an altered sandstone. The porcellanite
alluded to above is a white substance, varying from a dull earthy
aspect to that of a white enamel. It occurs of considerable thick-
ness along the outer surface of the pitchstone, and is clearly due to
a decomposition of this rock. The incipient stages of this decompo-
sition show a structure in the rock which otherwise we should not
have suspected. — The surface is traversed by a series of wavy lines,
conforming to one another throughout. This indicates a laminar
arrangement within; and it is along these lines that the rock
splits completely up in the advanced stages of the decomposition.

The relations of these various igneous products is further illus-
trated by another dike which occurs a little way up this river. A
great vein of claystone crossing the bed of the stream shows a
distinct passage into jaspery hornstone. The jasper and chert veins
in the Tormore pitchstone, with the associated claystones and basalts,
place these same relations in a very clear light; and when we view
the appearances which they exhibit in connection with those now
described, we cannot hesitate to admit that all these products of fire
blend into one another; the varying aspects which they assume being
due to a slight change in chemical composition, in molecular arrange-
ment of parts, or in the rate at which they were consolidated from a
state of igneous fusion.

150

THE FLORA OF ARRAN.

104. IN the preceding pages it has been shown how fine a field Arran
offers to the geologist, as exhibiting many diversified phenomena
in a limited area. To the botanist it is scarcely less interesting
— such is the luxuriance and variety of its vegetation — such the
rarity of some of the plants contained in its flora. It is, indeed,
true that scarcely any of these are botanical treasures of the first
order ; still there are several of unfrequent occurrence in the west of
Scotland, and many quite new and highly interesting to the
naturalist accustomed to the flora of England or the east coast.

This richness of Arran as a botanical field is owing to two causes
— its geographical position and the variety it affords of situation and
soil. Lying near the shores of the Scottish Lowlands, and at
the same time forming one of the Hebridean chain of islands, it
partakes of the flora of each region, — the common plants of its fields,
woods, marshes, and road-sides belonging chiefly to the former — the
maritime species to the latter. These advantages of position it no
doubt does in some measure share with the coasts of the Clyde
estuary generally, and especially with Bute ; in Arran, however, they
meet most completely ; and accordingly we find that no district of
equal extent in the west of Scotland can rival it in the number of
species. It is to this circumstance — its situation at the junction of
two dissimilar botanical provinces — that the peculiar richness and
variety of the flora of the island are mainly to be ascribed.

Secondly, The geological structure of Arran impresses a marked
character on its physical geography, and gives rise to the greatest
possible variety of station and soil. We have lofty and pre-
cipitous mountains, wide-spread moors, small alluvial plains, hot
and sheltered glens, damp woods, and sandy sea-shores. We have
every kind and degree of exposure, from the bare and wind-swept top
of Goatfell to the warm hollows of Glen Cloy, and this within the
compass of a few miles. We have modern fir plantations and natu-
ral birch woods ; cultivated fields and hedge-rows ; wide stretches
of peat-bog ; rocky promontories and caves ; open strands and sand

157

hills. Of soils, too, in the stricter sense of the word, there is a
notable variety. The general division of earths into sandy, loamy,
clayey, and so forth, is loose, and for scientific purposes inaccurate ;
distinctions far more natural, as well as valuable, are furnished by
the nature of the rocks, whose decomposed materials form the soil. In
Arran the variety of the geological formations produces a correspond-
ing diversity in the composition of the earths ; and though we are no
doubt still greatly in the dark as to the influence of soil on the
habitat of plants, there can yet be little doubt that the diversity of
soils furnished by the granites, traps, porphyries, slates, sandstones,
shales, and limestones, must exercise a powerful influence on the flora.
Whatever may be the importance of these conditions generally,
they certainly exist here in a remarkable degree.

To these advantages of geographical position and physical char-
acter is to be added the scarcely less important one of climate.
Lying off the west coast of Scotland, and thus almost in the
Atlantic, Arran enjoys a copious rain -fall, while its insular position
preserves it from those extremes of heat and cold which are so inju-
rious to vegetation. Hence it is that the climate, while in many
parts quite cold enough for the ordinary plants of Britain, and
while the mountains rise high enough to be a fit habitation for seve-
ral alpine species, is yet sufficiently mild and equable for the growth
of some usually found in more southerly regions. These conditions
exist also in the extreme point of Cantyre ; and accordingly we find
Campbelton enjoying the mildest winter in Scotland, and many ten-
der species flourishing there in the open air.

The effect of climate on the flora of Arran is twofold, — it increases
the number of species, and it imparts a general vigour and luxuriance
to the vegetation, which makes it interesting to the lover of the
landscape picturesque, no less than to the botanist. Every one must
have observed how much of the peculiar charm of Arran scenery is
owing to this circumstance. The bright green of the fields and
pastures, the woods that fringe the shore and cling to the slopes of
the lower hills, add grace and soft beauty to landscapes that would
otherwise be severe and gloomy in their grandeur ; and while they
pleasingly relieve the monotonous gray of the granite mountains,
serve to heighten by contrast the effect of the bare crags and jagged
peaks that rise behind them. In spring or early summer, when the
grass sprouts fresh on the hill-sides, and the varied foliage of the
trees still preserves the delicate green of youth, or in July, when the
lower ridges are purple with the rich heather-bloom, this variety
of colour is finest, — and this is the best time to see Arran scenery in

158

its perfection. In September, the grass is parched, the heather
begins to wither, and a brown or gray tint prevails over the
whole landscape, little relieved even by the red and yellow hues
of the autumnal trees. While, again, if we turn our attention
from the general outlines of the scene, and look more closely at its
details, we shall find no less cause to admire the effects of an
atmosphere moist and warm. To it we owe not only the abundant
growth of natural wood which clothes the glens and sea-cliffs, but
also the size and splendour of many of our finest shrubs and wild
flowers, such as the laburnum, the hawthorn, the foxglove, the
honeysuckle, and perhaps most strikingly of all, the luxuriant
profusion of the whole fern tribe, from the stately Osmunda to
the lowly Hymenophyllum.

105. On proceeding to analyze the flora of a given district, that is,
to examine the internal relations of its constituent parts, noting what
species, or genera, or families, are abundant, what rare, and what
character is thus imparted to the vegetation, we may regard
it under two aspects, as illustrating the peculiar features of the
tract itself, or as indicating the relations of that tract to the
surrounding regions, — what may be called its general botanico-
geographical position. Glancing at the flora of Arran from this
latter point of view, we shall observe some interesting facts.
Writers on the botanical geography of Britain class the plants
of our country according to several " types of distribution," to
denote their geographical range and affinities. Thus many species,
occurring chiefly in the east and south of England, are assigned to
the Germanic type ; others, most of them denizens of the Scottish
Highlands, are referred to the Scandinavian ; while others again,
characterizing Ireland and the westerly coasts of Britain, are grouped
under the Atlantic type. Some few there are, found only in Corn-
wall and the west of Ireland, whose affinities are with the Spanish
Peninsula, and especially with the mountains of the Asturias, and for
these there is proposed a Lusitanian type. Somewhat similar to the
position of Britain, if we may be allowed to compare great things
with small, is the position of Arran. Most of its common species — •
the plants of the field, the road-side, the marsh — it has in common
with the western Lowlands of Scotland, which stand to it in the same
relation that the continent does to England. These Lowland plants
form the bulk of its flora. They include almost all those of common
occurrence, as well as several of the rarer sort — such as Ranunculus
Lingua, Heliantliemum vulgare, Epipactis ensifolia, Samolus Vale~
randij the BotrycMum and Ophioglossum, A splenium ruta-muraria,

159

&c. Under this class are embraced nearly all the species that
frequent the cultivated land, the marshes and streams, the woods
and pastures ; together with several maritime ones — as Silene mari-
tima, Oenanthe Lachenalii, Calystegia Soldanella.

A second "type" discernible in Arran is that which we might call
the Highland. To this group belong the alpine plants of the highest
granite mountains — Salix herbacea, Thalictrum alpinum, Alchemilla
alpina, Cryptogramma crispa, and others ; several also occurring in
elevated situations in various parts of the island — as Rhodiola rosea,
Oxyria reniformis, Hymenophyllum Wilsoni; besides a few found in
mountainous regions, though at no great altitude — such as Cory-
dalis claviculata and Polypodium Dryopteris.

Thirdly, We have a considerable class occupying, as it were, in
Arran, the place which the Atlantic type holds in Britain, including
the plants peculiar to the west coast, and especially frequent in the
Hebridean chain of islands. Such are many of the maritime species
— Mertensia maritima, Brassica Monensis, Sedum anglicum, Rapha-
nus maritimus, as well as Pinguicula lusitanica, Gymnadenia conop-
sea, Drosera anglica, and Listera cordata — plants found in various
localities through the interior. This class includes many of the most
interesting and characteristic plants of the island — not a few of them
such as will be entirely new to the English botanist.

But the most curious feature in the botanical geography of Arran
is the occurrence in its southern extremity of several species scarcely
elsewhere to be found in Scotland ; belonging, in fact, to the flora of
central England, and here apparently quite projected, so to speak,
from their ordinary range. Of these the most remarkable are the
Lathyrus sylvestris, Verbascum thapsus, Inula helenium, Althaea
officinalis, Carlina vulgaris. They all occur within the circuit
of a mile, on the warm southern face of the cliffs and steep allu-
vial banks that front the sea at the extreme south of the
island, near Benan-head. No one who examines the locality can
think it possible that they should have escaped from cultivation ;
and it is scarcely less improbable that they should have been planted
there by the hand of man. The Lathyrus, Verbascum, and Car-
lina are still abundant ; the Inula, however, seems to have been extir-
pated, if indeed the report of its existence was correct. It is cer-
tainly not to be found now, yet it is difficult to see how the mistake
could have arisen, as there is no plant in the neighbourhood which
would be readily mistaken for it. The Althaea has been found
within the last few years, but is now either extinct or very scarce.
It is to be hoped that botanical collectors who may visit the spot

160

will spare the beautiful Lathyrus, and refrain from extirpating it in
what is probably its only Scotch locality.

106. Having remarked thus on the external relations of Arran to the
botanical geography of the surrounding lands, we might pass on to
speak of its internal aspects, and notice the several floras of the
mountain, the glen, and the shore, the moor, the wood, and the
marsh ; in other words, to distribute the plants according to their
respective botanical stations. By such an examination, however, no
new facts or principles of peculiar interest would be elicited. A
little experience will enable the student to frame such a classification
for himself.

Most of the rare plants of Arran are to be obtained on or near
to the coast, some decking the bright sands, as the Brassica
Monensis, the purple Mertensia, or oyster plant, as it is called
from the flavour of its leaves, and the lovely Calystegia Soldan-
dla, with its creeping stems and flowers of delicate pink ; some
dwelling in the salt marsh and wet grounds that lie between the old
sea cliff and the present tide-mark, such as the Oenantlie Lachenalii,
Triglochin maritimum, and palustre, the pretty little Glaux, the
blue Aster, and several others. Here, too, though not properly
maritime plants, we often find the handsome Parnassia, and delicate
Anagallis tenella, Samolus Valerandi, Orchis latifolia, and in the
drier spots, Geranium pratense and Erythrcea linearifolia. The
bare rocky crags and promontories, which here and there diversify
the generally accessible coast of the island, are gay with the brillian^
white, yellow, and pink flowers of Sedum Anglicum and acre, Silene
maritima and Spergularia marina; the succulent Cotyledon fixing
its roots in the rock clefts, and the glossy green of the sea spleen -
wort, Asplenium marinum. The curious sea cliff which lines the
coast of the island in almost every part, marking the level at which
the sea stood in some former age, is in most places thickly covered
with a natural growth of oak, ash, birch, hazel, and other trees, and
is kept moist by the numerous streams that trickle down its face, or
precipitate themselves in cascades from its edge. The shade and
humidity thus produced render its vegetation luxuriant and varied ;
and we find many interesting species growing on or near this line of
irregular cliff, some hanging from its wooded sides, some springing
rank in the wet caves that pierce it, and some inhabiting the stony
and marshy ground at its base.

Here, among others, occur Veronica montana, Hypericum And-
rosaemum, Geranium sanguineum, Sanicula europaea, Eupatorium
cannabinum, Lycopus europaeus, Listera ovata, Hdbenaria chlor-

161

antha. Here too most of the Arran ferns may be found ; — Polypodium
Dryopteris and Phegopteris, Cystopteris fragilis, Aspidium or Lastrea
recurva (foenisecii), Aspidium lobatum and aculeatum, Asplenium
marinum, Hymenophyllum Tunbridgense and Wilsoni, and the
magnificent Osmunda regalis. In enumerating these plants, we do
not mean that they are all to be met with in any one spot, but that
they all occur in some part or other of the sea cliff, while many
abound through the whole of its long extent. Those species which
we have just mentioned, with the addition of one or two rarities,
such as Epipactis ensifolia and Thalictrum flavum, form in the
main the sylvestral flora of the island, which it is therefore needless
to speak of more particularly. Similarly, there is little to dis-
tinguish the vegetation of the lower glens from that we have
described as characteristic of the sea cliff and the woods, not, at
least, till the point is reached where the larger trees grow scarce?
finally giving place to thickets of birch or hazel, or to the open
expanse of pasture and moor. Here the aspect of the scene is
changed, and plants quite different attract the attention of the
botanist. The greensward is gay with the purple Gymnadenia
conopsea, as beautiful as it is fragrant, the blue Jasione montana,
Pimpinella saxifraya, Gentiana campestris, Erythraea centaurium,
Hdbenaria viridis and albida, Orchis maculata, and many other hand-
some plants. Nestling among the heather we may find Circaea
alpina, Listera cordata, with its slender stem and minute yellowish
flowers, the taller Galium boreale, and the tender green of the oak
fern, Polypodium Dryopteris. Rubus saxatilis here and there trails
its long stems over the stony ground, while the viscid leaves of the
sundew, Drosera rotundifolia and anglica, the tiny cream-coloured
flowers of Pinguicula Lusitanica, and straggling yellowish- green
stems of the little Lycopodium selaginoides, mix with the moss that
grows thick round the margin of the springs and rivulets. Suppos-
ing the glen, whose botany we have been describing, to be in the
southern division of the island, we shall, on ascending still higher,
find ourselves, after a stiff climb, on a wide expanse of undulating
moorland, covered by a thick deposit of peat bog, interrupted here
and there by a rocky hilltop, or the deep cut channel of some moun-
tain burn. These moors, varying in height from 900 to 1,400 feet,
have little to interest the botanist. He may travel over them for a
whole day without meeting more than two or three species among
the coarse grass and heather, mixed with rushes and cotton grass,
which clothe the surface of the peat moss. Generally it may be said,
that the flora of the higher grounds in Arran is inferior to that

T

162

of the low country. The granite mountains in the northern part of
the island rise quite into the alpine region, and are covered with
snow for seven or eight months in the year. Yet, when compared
with the mountain tracts of the central Highlands, they will be
found to possess few alpine plants. This fact seems to be mainly
owing to that predominance of bare rock over grass and heather,
which gives them, at some distance, the appearance of an unbroken
mass of gray granite. Besides the stony character of the mountain
slopes, the thinness and ungeniality of the soil furnished by the
decomposed granite, the absence in the higher regions of springs
and streamlets, and perhaps the very steepness of the loftier
summits, may all contribute to render the alpine flora of Arran
comparatively scanty and uninteresting. The commonest plants
on the high mountains are Saxifraga stellaris and Alchemilla
alpina; the former is scarce on Goatfell, occurring more abundantly
on the heights round the head of Glen Sannox; the latter is very
frequent on all the higher peaks, and covers, with the graceful
drapery of its silky leaves, the ledges of many a granite precipice.
Salix h&rbacea — the dwarf willow, whose woody stem scarcely rises
from the ground — is found on most of the principal summits; Oxyria
reniformis and Rhodiola rosea grow abundantly in the rock clefts ;
Circaea alpina and Saxifraga hypnoides occur occasionally near the
summits of the southern hills ; the pretty little TJialictrum al-pinum
may be found in many places, as on Ben-Varen, on Goatfell, at the
head of Glen Cloy, and on the summit of the pass leading from Glen
Eosa into Glen Sannox ; Cryptogramma crispa, the parsley fern, has
been noticed in several spots, rooting deep among the loose blocks of
stone that strew the mountain- side, while among the other crypto-
gamous plants, Polypodium Dryopteris and Phegopt&ris, Cystopt&ris
fragilis, Hymenophyllum Wtisoni, and several of the alpine Lycopodia,
may be enumerated as denizens of the glens and mountains.

Regarding the water plants of the island, those which we find
in its marshes and streams, there is but little to be said. They are
few in number, and not in any way remarkable. The list is nearly
exhausted by the names of Hypericum elodes, Ranunculus lingua,
Dros&ra Anglica, Littordla lacustris, Alisma plantago and rcmun-
culoides, and several species of Potamogeton and Carex. Of true
lake plants there are very few ; and this fact leads us to observe how
deficient Arran is in this element of the picturesque. Lakes there are
several, but, with scarcely an exception, they are placed in the high
bleak moors, far above the limit to which trees ascend, and generally
away from the higher mountains, so that they add little either of

163

beauty or of sublimity to the scenery of the island. Loch Tanna,
by far the largest, lies in a high and gloomy plateau strewed with
blocks of decomposing granite, among which the stunted heather
barely supports its existence — itself as black and uninteresting a
sheet of water as any pool in the fens of Lincolnshire ; the aspect of
the whole scene is one of utter wildness and desolation, without
grandeur. The absence, however, of this element of the beautiful in
Arran scenery is scarcely remarked, being more than compensated
by the character which the sea imparts to every landscape.

107. Having thus briefly indicated the plants which the botanist
will meet with in each region of the island, it is scarcely necessary to
prescribe for him any special excursion or walks. These are best
left to his own taste and convenience. It may, however, be not
amiss, in a few concluding words, to direct him to the districts where
his rambles will be attended with most pleasure and success. Pro-
bably no part of the island will offer to him so many interesting species
as the vicinity of Brodick, especially if he direct his walks to the
Corriegills shore, proceed northwards to Corrie, or explore the
tangled thickets and dripping rocks at the head of Glen Cloy.
Around Loch Ranza, too, several excellent plants may be obtained ;
while, even if the tourist be not botanically inclined, he will find
in the exceeding beauty of the coast an ample reward for his
walk along the lovely shore between Glen Sannox and Newton Point.
The western coast offers many striking scenes, and everywhere com-
mands noble views of the broad sound of Kibrannan, with the hills
and glens of Cantire beyond ; but its botany presents little that is
new to one who has already examined the eastern part of the island ;
while the interior of the country is occupied by undulating granite
mountains, seldom, except at Glen Catacol, assuming forms of
sublimity or beauty, and clothed with no vegetation beyond the grass
and heather that grow among the slowly-decomposing blocks of gray
granite with which the ground is strewed for miles. Such is the
aspect of the country — bleak, wild, unvaried — -from Loch Ranza
to Loch lorsa and Dugarry, where the slate and old red sand-
stone formations succeed the harsher granite, and subside with
gentle declivities into the alluvial plain through which the
Mauchrie water finds its way to the sea. Despite what we have
said of the botanical attractions of Brodick, there is no dis-
trict in Arran that will better repay the trouble of a visit than
the south coast, from Slaodridh to Whiting Bay. Without any of
the alpine grandeur of the north, it has many striking beauties of
its own; smiling little bays, steep green banks, and bold cliffs of

1G4

basaltic rock, trap, porphyry, or claystoiie, jutting far out among the
waves, or running in tall colonnades along the shore ; seaward there
is the wide expanse of glorious blue, with the magnificent pinnacle of
Ailsa full in front ; beyond all, closing the distant horizon, the gleaming
cliffs of Ayrshire, and the far-off coast of Ireland. It is a delightful
shore to wander along slowly, searching and prying for rarities
in the salt-marsh by the water's brink, or up some leafy gorge
through which the streamlet from the hills forces its seaward way,
forgetting the world without and all its cares, delivered from the
dominion of dusty roads, and the necessity of getting home in time
for dinner. Let the naturalist take up his quarters in the neat little
inn that lies nestling in its snug little hollow at Lag; there he may
pass happy days in exploring that solitary shore, and at night pull
out into the deep, and taste the unwonted pleasures of sea-fishing.
From this point also the agriculturist may visit some of the fine
farms along the south coast, where the best methods of cultivation
are practised.

The mountains at the head of Glen Sannox will be found
richer in alpine plants than Goatfell, though scarcely equalling
it in height. Yet even their flora must appear scant and un-
interesting to one who has botanized over the ranges of the
central and eastern Highlands, Ben-Lawers, Braemar, or Clova.
But at this he will have no cause to repine when he finds himself
led into some of the most magnificent mountain scenery in Britain.
It has been said that no scenery in Scotland but that of
Coruisk in Skye, and that of Glencoe, can rival the grandeur of Glen
Sannox ; certainly neither the famed Perthshire Highlands, nor the
English lakes, can show anything as wildly sublime as the precipices
and aiguilles of rifted granite which tower around the heads of these
Arran glens.

LIST OF PLANTS.

108. The following list comprises only the rarer plants of Arran,
including under this title both those which, though frequent in the
west of Scotland, are seldom found in other parts of the country,
and those which, while abundant in Britain, may appear rarities to
one who knows only the botany of the west coast. It often
becomes very difficult to draw the line, and to say what plants should
be omitted and what inserted. We cannot hope to have decided
always judiciously ; when we have erred it has probably been in
admitting plants which may appear common to the practised botanist.

1G5

All the species of the fern tribe known to exist in the island have
been inserted, and their localities given in full detail ; partly because
they bear a larger proportion than usual to the flora of Arran, and
partly for the sake of those who may take a special interest in them,
or wish to procure specimens for cultivation.

The genera are arranged according to the natural orders, and the
names those which appear in Hooker and Arnott's British Flora.

Our best thanks are due to Professor J. Hutton Balfour of
Edinburgh, for his kindness in placing his lists at our disposal.
On the authority of these many species have been inserted. A few
not observed either by Dr. Balfour or ourselves are inserted on
the authority of the late Dr. Landsborough. To these the letter L
is affixed. Plants which we suspect to be not truly wild are
indicated by an asterisk. We may add, that as such a catalogue can
have no claims to perfection, any hints for its correction or extension
will be gratefully received.

r™ r . ,. f Goatfell, head of Glen Sannox, Ben-

Ihalictrum alpmum, . . .{ yaren, head of Glen Cloy.

flavum, . . Whiting Bay (L).

minus, ,. . Whiting Bay.

Ranunculus hederaceus, . . In many places.

Lingua, . . Lamlash.

acris (var. pumilus), Near Lamlash.

sceleratus, .

Trollius Europseus,

Corydalis claviculata, . . House roofs and woody places.

Cardamine pratensis, . . Abundant.

hirsuta, . . Near Lamlash.

Cochlearia officinalis (several vars.) On the shores.

Cakile maritima, . . ".."' Frequent on sandy shores.

Lepidium Smithii, . . . Brodick.

— . campestre, . . Loch Ranza (?)

Sisymbrium Sophia, . . Sandy sea shores.

T> • TVT • f Sands at Brodick, Sannox, Black-

Brassica Monensis, . .j Water.fOot, &c.

oleracea, . . . Lag.

campestris, . . " . Mauchrie.

Crambe maritima, . . . Imochair.

Raphanus maritimus, . *.'"" Southend.

Helianthemum vulgare, . . Kildonan.
Viola tricolor (var. arvensis) .

palustris, . . Marshy places.

Drosera Anglica, . . . Frequent.

rotundifolia, . . Do.

Parnassia palustris, . . Do.

Silene maritima, . . Shores — frequent.

Lychnis diurna, . . . Common.

vespertina, . . Do.

Agrostemma Githago, . . Cornfields — common.
Sagina maritima, . . . On the shores.
— nodosa, . . Lamlash.

166

Honckenya peploides,
Stellaria media,

holostea, .

Spergularia marina,
Radiola millegrana,
AlthaBa officinalis, .
Malva sylvestris,
Hypericum perforatum,

dubium,

Androsaemum,

quadrangulum,

humifusum,

pulchrum,

hirsutum,

elodes,

Geranium pratense,

• sanguineum,
— — dissectum,

pusillum,

Oxalis acetosella, .
Trifolium filiforme,

• medium,

procumbens,

Anthyllis vulneraria,
Lotus major, .
Orobus tuberosus, .
Vicia sjrlvatica,
hirsuta,

Cracca,

sepium,

Lathyrus sylvestris,
Geum intermedium,

urbanum,

rivale,

Comarum palustre,
Alchemilla vulgaris,

alpina, .

do. (var. con uncta),

- ' arvensis,

Agrimonia Eupatoria,
Prunus communis,
Rosa spinosissima, .
canina,

involuta,

tomentosa,

villosa, .

Pyrus aucuparia, .

pinnatifida, .

Rubus carpinifolms,

corylifolius,

Idaeus,

saxatilis,

suberectus,

glandulosus,

rhanmifolius,

Circaea Lutetiana, .

Sandy shores.
Frequent.

Do.

On the coast.

Goatfell, Loch Ranza, Springbank.
Struey Rocks (?)

In several places.

j Invercloy, Whiting Bay, &c., abun-
'\ dant.
Frequent.
Wet places.
Frequent.

Do.

Lamlash.

King's Cove and Loch Ranza.
Brodick, Benan-head, Holy Isle, &c.
Struey, Thundergay, Dippen.
Frequent.

Do.

Do.

Frequent.

Common.

In the woods.

King's Cove, Kildonan, &c.

Frequent.

Do.

Struey Rocks.
Frequent.
Common.
Frequent.
Frequent.
Common.
On the mountains.
Glen Sannox.
Frequent.
On the south coast.

Frequent.
Common.
Lamlash.
Dippen.

Frequent.

Glen Eis-na-vearraid, Caistael Abhael.

Lamlash.

Do.

Woods and mountains — frequent.
Head of Glen Cloy.
Holy Island an^ T «mlash.

Frequent.

167

Circaea alpina,
Peplis Portula,
Lythrum salicaria, .
Montia fontana,
Scleranthus annuus,
Cotyledon umbilicus,
Sedum Rhodiola, .

*Telephium,

acre, .

Anglicum, .

Saxifraga stellaris,

hypnoides,

Hydrocotyle vulgaris,
JEthusa Cynapium,
Sanicula Europaea,
Eryngium maritimum, .
Bunium flexuosum,
Helosciadium nodiflorum,

- do. (Var. repens),
Carum *Carui,
Pimpinella Saxifraga,
Oenanthe Lachenalii,
Conium maculatum,
Smyrnium olusatrum,
Scandix Pecten,
Myrrhis odorata, .
Li^usticum Scoticum,
Apium graveolens,

Galium boreale,

Asperula odorata,
Valeriana officinalis,
Fedia dentata,
Cnicus pratensis,
Carlina vulgaris,
Carduus palustris,
Bidens cernua,

tripartita,

Inula Helenium,
Eupatorium cannabinum,
Antennaria dioica,
Cichorium Intybus, ' .
Gnaphalium uliginosum,
sylvaticum,

Glen Cloy, Bein Leister Glen.
Frequent.

In many places.
Frequent.
Mountains — frequent.

Frequent on the shores.

Common.

Mountains — fr equen t .

Glen Cloy, &c.

Common.

Waste ground.

Thickets.

Sandy shores.

Frequent.

Shore at Leac-a-Breac.

Lamlash.

Frequent.

Cprriegills, &c.

Dippen, Lag.

Dippen (L).

Frequent.

Dippen.

Southend, Kildonan, &c.

Shore at Lag, and Loch Ranza.

JGlen Laodh, North Sannox, and
other places,
woods.
Frequent.
Loch Ranza.

Struey Rocks.

Brodick.
Lamlash.
Struey Rocks (?)
In many places.
Pastures and moors.
Whiting Bay.
Loch Ranza.
Loch Ranza.
Salt marshes.
Near Lamlash.

Aster Tripolium,
Hieracium murorum,

sylvaticum (var. vulgatum)Glen Eis-na-vearraid.

Filago Germanica, . . Brodick, Glen Eisdale.

minima, . '-. . Glen Eisdale.

Solidago virgaurea, . . * Glens — frequent.

Senecio sylvaticus, . • . Lamlash.

Pulicaria dysenterica, . . Struey Rocks.

Matricaria maritima, . . Sea coast.

Jasione montana, . . . Common.

Lobelia Dortmanna, . > Small loch at Loch Ranza ; Loch lorsa.

Vaccinium Myrtillus, . . Frequent.

Vitis-Idaea, . . On the higher mountains.

168

Arctostaphylos Uva-ursi,
Pyrola minor,
Ilex Aquifolium, .
Fraxinus excelsior,
Erythrasa Centaurium, .

linearifolia,

Gentiana campestris,
Menyanthes trifoliata,. .
Convolvulus arvensis,
Calystegia sepium,

Soldanella,

Cuscuta *epilinum,
Lithospermum officinale,

arvense,

Mertensia maritima,

Solanum Dulcamara,

Veronica montana,

Melampyrum pratense, .

Scrophularia aquatica, .

Digitalis purpurea,

Linaria vulgaris,

Verbascum Thapsus,

Lycopus Europaeus,

Mentha sylvestris (var. velutina),

sativa (var. rubra), .

viridis,

— — — rotundifolia,
Galeopsis versicolor,
Calamintha Clinopodium (?)
Lamium amplexicaule, .
— iucisum (?)

intermedium, .

Stachys ambigua,
Scutellaria galericulata,
Origanum vulgare (?) .
Pinguicula vulgaris,

Lusitanica,

Utricularia vulgaris,

minor,

Glaux maritima, .
Anagallis arvensis,

tenella, . ...

Samolus Valerandi,
Armeria maritima, .
Littorella lacustris,
Plantago maritima,

coronopus,

Atriplex laciniata, .

angustifolia,

do. (var. erecta),

Salicornia herbacea,
Suaeda maritima, .
Salsola Kali, ....
Rumex conglomeratus, .
— — pratensis, .
Polygonun Raii,
Convolvulus,

Holy Isle, Glen Eis-na-vearraid.

Holy Island (L).

On the cliffs.

Rocks at Glen Catacol.

Frequent.

Shore at Corriegills, &c.

Moors and pastures.

Springbank, &c.

Corrie.

Hedges — frequent.

Black-Water-foot.

Lamlash.

Loch Ranza.

On the sands, Brodick, Sannox, &c.

Brodick, Holy Island, &c.

Blue Rock, &c.

Abundant.

Near Sannox.

Frequent.

Cliffs at Struey and Dippen.
Sannox.

Lamlash and Whiting Bay.

Near Corrie.

Brodick.

Frequent.

Loch Ranza.

Do.

Lamlash, Kildonan, Mauchrie, &c.
Slaodridh.
Brodick, Struey, &c.

Abundant.

In the bogs. — now less frequent.

Loch-in-Davie, Loch lorsa.

Loch on the shore, near Mauchrie.

Salt marshes.

In cultivated ground.

Abundant in the bogs.

Marshes —frequent.

Sea shore — abundant.

Loch Ranza.

On the shores.

Dry places.

Sea shores.

Shore at Struey.

Slaodridh.

Loch Ranza.

On the shores — Loch Ranza, &c.

Sandy shores — frequent.

Lamlash.

Shore at Lamlash, Lag, &c.

On the shores.

1C9

Oxyria reniformis, .
Empetrum nigrum,
Panetaria officinalis,
Ulmus montana, .
Callitriche pedunculata,
Myrica Gale,
Betula alba, .
Salix herbacea,
Corylus Avellana,
Populus tremula,
Juniperus communis,

nana,

Epipactis ensifolia,
Listera ovata,

cordata,

Orchis mascula,
— — maculata,

latifolia,

Habenaria bifolia,
Chlorantha, .

• viridis, j

albida, . . . ^

Liparis Loeselii (?) * . •;<
Gymnadenia conopsea, .
JVlalaxis paludosa,
Allium ursinum, . . *

* Schoenoprasum, .

Agraphis nutans, . . '•„. •
Juncus triglumis, .

trifidus,

compressus (var. Gerardi),

Juncus glaucus,

maritimus, . »

Narthecium ossifragum,
Alisma Plantago, .

ranunculoides, .

Triglochin palustre,

maritimum, .

Typha latifolia,
Sparganium ramosum, .

simplex, . .

Potamogeton plantagineus, .

oblongus, .

Zostera marina,
Eriophorum vaginatum,

polystachion,

. angustifolium,

Schoenus nigricans,
Eleocharis palustris,

do. (var. uniglumis),

multicaulis, .

Blysmus rufus,

compressus,

Scirpus maritimus,

pauciflorus,

Carex ampullacea,

Mountains.

Lag.

Brodick Castle.

Abundant.

Frequent.

Mountain tops.

Abundant.

Torlin.

Mountains.

Goatfell (?)

Slaodridh, Invercloy, Whiting Bay.

Lamlash.

Cior-Vor, Suithi-Feargus, Glen Cloy.

Abundant.

Do.

Do.

Do.

Do.
Whitefarland, Eiss-a-mhor, Loch

Ranza.

Loch Ranza; and dry heaths, in
many places.

Abundant in fields and heaths.

Kildonan.

Abundant.

Glen Shirag.

Abundant.

GoatfeU.

Do.

Salt marshes.
Torlin.
Sea shores.
Abundant.
Brodick, &c.
In several places.
Frequent.
Salt marshes.

Mill-dam, Whiting Bay, &c.
Lamlash.

Brodick.
Loch-in-Davie.
Abundant.
GoatfeU.

Abundant.
Sea shores.

Do.

Sands near Kildonan, and at Lag.
On the coast.
On the sea shore.

Do.

Do.

Corriegills, and Come shore-
Near Mauchrie.

170

Carex laevigata,

vulpina,

pauciflora,

arenaria,

remota,

curta,

divisa,

distans,

extensa,

— fulva,

glauca,

muricata,

— ovalis,

Oederi,

paniculata,

rigida,

Rhyncospora alba,
Isolepis Savii,
setacea,

Avena planiculmis,

Ammophila arundinacea,

Elymus arenarius, .

Briza media (?)

Aira alpina, ....

Brachypodium sylvaticum,

Catabrosa aquatica,

Festuca bromoides,

gigantea, .

vivipara,

Molinia coerulea (var. alpina),
Poa maritima,
Triticum junceum,

laxum,

Polypodium vulgare,

Phegopteris,

Dryopteris,

Aspidium lobatum,
aculeatum,

i Road-side, between Brodick and
< Lamlash ; Loch Ranza, Corrie-
I gills.

Snores.

Ascent of Goatfell, and in Glen Rosa.

Sandy shores.

On the moors.

Frequent.

Imochair.

Dippen.
Near Dugarry.

'Goatfell.

North Glen Sannox, &c.

Corrie.

Frequent.

TSaid to have been found in Glen
\ Sannox.

On the shores.

Sandy shores.

'Goatfell (?)
Woods.

Shore at Kildonan and Lag.
Lamlash.
Corriegills.
Goatfell.
Mountains.
On the shores.
Shore at Slaodridh.
Sands at Struey.
Very common.

[Abundant in the woods, and along
the sea cliff; frequent also in
sheltered spots in the glens ; and
sometimes found in rock crevices
at the tops of the highest moun-
tains.

f In the woods, and very abundant in
damp sheltered spots in the glens
.-{ and among the heather; often
ascending the highest mountains
t along with the last species.
("Frequent on cliffs and banks near
1 the sea ; sometimes in exposed
*1 situations, passing into a form
i. resembling Aspidium lonchitis.
Frequent in hedges and woods.
'Very abundant in the glens and on
the moors, often, as in the lower
part of Glen Rosa, covering the
whole hill-side with the delicate
yellowish-green of its young fronds.

171

Aspidium Filix mas,

spinulosum,

recurvum (Foenisecii),

Cystopteris fragilis,

Asplejiiuin Ruta-muraria,
Trichomanes,

viride,

marinum.

Adiantum nigrum,

Filix-fcemina (Athyrium

Filix-foemina), .

Scolopendrium vulgare,
Pteris aquilina,

Cryptogramma crispa,

Blechnum boreale,

Botrychium Lunaria,

Abundant everywhere.

This variable and perplexing species
is very abundant in several varie-
ties, one of which, with an ovate
or ovate-lanceolate frond, is fre-
quent on the highest mountains.

Frequent on the sea cliff— as at
Corrie, North Sannox, Salt Pans,
and Whiting Bay ; in rocky and
wooded ground at the head of
Glen Cloy, under the Sheeans.
'Rocks at the head of Glen Cloy;
cave in the old sea cliff at Blue
Rock; near Glen Sannox; and
in several other spots among the
mountains, as, near the top of
Ben-Ghnuis, on the Ceims, &c.
It generally, if not always, occurs
in the form dentata.
? Old walls at Brodick Castle, and
\ probably in other places.

Common on rocks and walls,
f Abundant on limestone cliffs at the
I head of Bein-Leister Glen, above
Lamlash ; on rocks near the head
of Glen Cloy, sparingly.

Occurring here and there in caves
along the old sea cliff. It is now
scarcely to be found on the east
and north coasts of the island, but
may be obtained in many places on
the south and west, as at Benan-
head, King's Cove, and Imochair.
At Leac-a-Breac, near Black-
Water-foot, we have gathered
fronds eighteen inches long.

Abundant on banks and rocks.

5 Very abundant and beautiful, and
presenting an infinite variety of
forms.

/ Hedges, banks, and rocks ; often
*\ very luxuriant.
Very common.

Among granite blocks at the head
of Glen Sannox, under the crags
of Cior-Mhor, abundant ; also on
the pass leading from Glen Rosa
into lorsa, in small quantity, and
probably in several other places.
One very small plant we found,
on one occasion, at the summit of
Ben-Ghnuis.
Common.

f Fields near the String Road in Glen
Shirag ; also on the shore at In-
.<J vercloy and Corriegills, and in
dry pastures in several other

I

172

Hymenophyllum Tunbridgense,

._ Wilsoni,

Osmunda regalis,

Ophioglossum vulgatum,

Lycopodium clavatum, .
Selago,

annotinum, .

selaginoides,
alpinum,

Equisetum fluviatile (Telmateia),
arvense,

sylvaticum, .

limosum,
palustre,

f On sheltered rocks in several places,
as in a plantation near Invercloy,
in the wood at Brodick Castle ;
near Corrie ; at Fallen Rocks ; and
at the entrance of Glen Eisdale,
Whiting Bay. It is remarkable

• that, in all these localities, it is
found growing upon the old sea
cliff; as is also the case where it
occurs at Dunoon, Holy Loch,
the Kyles of Bute, and the shores
of Lochlomond, at Tarbet.

f Abundant in many spots, as near
Corrie ; sea coast at Sannox ; Glen
Cloy, Bein-Leister Glen; Birk
Glen, above Invercloy, often
growing along with the last-men-
tioned species, but also ascending
to the tops of the highest moun-
tains, where, as on Ben-Ghnuis.
it covers the most exposed* rocks
at a height of 2,500 feet, and is
with difficulty distinguished from
a moss. In general, it prefers
damper spots than H. Tunbrid-
gense, and can stand exposure
much better.

Frequent, on the sea cliff, all round
the island, often very luxuriant,
attaining the height of 10 or even
12 feet. Now less abundant on
the coast, but may be found in
profusion near Loch Ranza, and
at King's Cove.

{In a meadow between Benan -head
and Torlin, and probably in other
places.

Abundant on the hills.
Moors and mountains — frequent.
( Said to have been found on Goat-
. < fell, but in all probability errone-
( ously.

( Boggy and springy places on the
' \ hills and glens — frequent.
On the mountains.
Frequent in damp ground.
Common.

/ In the woods and glens, not un-
\ frequent.
Ditches and ponds.
Boggy places — frequent.

173

MARINE ZOOLOGY OF ARRAN.

109. THE coast-line of Arran abounds with objects of interest.
Nor is this interest confined to geological science. The naturalist —
and especially the student of marine zoology — will find here a field
for investigation ; and even the casual visitor, if endowed with the
faculty of inquisitiveness, may obtain instructive and amusing
occupation.

Let it be understood that the waters of the sea, generally, teem
with animated beings of an endless variety in form, size, and struc-
* ture, and that myriads of these creatures are the inhabitants of
rock-pools, where they share the vicissitudes common to mortality —
sporting, at one moment, in the full enjoyment of the pleasures of
life, and at another instant either wrangling or wrestling with an
antagonist — perhaps for a mouthful of food — or "scudding" with
all their might from the open jaws of an approaching and ravenous
enemy.

We will suppose that we are now standing at Corriegills, on the
sea shore in Brodick bay, about one mile from Invercloy. The rocks
are of the red sandstone formation ; and the soft material, yielding
to the action of ceaseless tides, and to the lashing waves of the
winter storm, has been hewn in all directions into fissures and small
basins, which, renewed with fresh supplies of water by each return-
ing flood, are the " habitats" of plants and animals. Look into
these adjacent pools. They appear to be almost covered with tiny
sea-weeds. Yet the jungles of India are not more fully occupied
with their appropriate denizens than are these patches of the sea.
They abound with microscopic life, generated under the warmth of
the sun ; and, by stooping down and watching for an instant, you
will observe as much bustle, enterprise, and activity, with the usual
accompaniments of success and misfortune, as are characteristic of
an opulent city. The water at this moment is perfectly still. There
is not a breath of air to disturb its surface. But do you notice that
ripple ? Depend upon it there is some mischief not far off See !
there is a prawn, or something like a prawn, swimming with the

174

greatest eagerness towards a piece of rock almost concealed by
marine vegetation. Nay, there is a whole fleet of these creatures,
trying to outvie each other in speed, and all shaping their course
in the same direction. With the help of our gauze or muslin landing-
net we will endeavour to catch a specimen. Skill and patience are
required, for they are uncommonly agile — they leap with the sudden-
ness and rapidity of a grasshopper, and they are too " knowing" to
enter a bag, however fine may be its fabric, unless they are enticed
or surprised by stratagem. Look how carefully that individual is
keeping his face towards your net — see how deliberately he " backs
astern," with an occasional jump, when you think that he cannot
possibly escape : — but now, keep your hand steady ; he will approach ;
he will inspect your net with all imaginable curiosity. Observe how
skilfully he uses his "horns," or antennae — exquisitely formed
instruments, half as long again as his entire body, and which, as with
the insect tribes, are delicate organs of inquiry. He will creep
round the net and touch every part within his reach. But stop —
here is a chance of catching him — run him gently back into that'*'
nook in his immediate rear, dip your net under him, and then, if
you are smart in raising your hand, he will be your prisoner. Bring
him on shore, and, inverting the net into a glass vessel of sea water,
we will be able to examine him at leisure. But what has become
of his companions ? Whither were they bound ? And on what
errand were they so swift ? It is a case of piracy. These crusta-
ceans, which we saw swimming in such haste, are a fleet of sea-
robbers ; they are at this moment plundering a colony of helpless
zoophytes, and, as often happens under analogous circumstances,
they are quarrelling among themselves. Look, first, at these two
warlike specimens of their race engaged in combat — each endeavour-
ing to get at the prey. They do not appear to use their eyes,
although these organs are well developed ; but, feeling about on all
sides with their antenna, they no sooner touch each other than the
strongest of the two rushes forward, assaults, and beats back the
weaker, which, after being foiled in repeated attempts to hold his
position and obtain a share of the spoil, retires to another portion
of the invaded colony. Now observe their thieving propensities.
Here is a group of sea anemones, just below the surface of the pool,
curiously fixed with their base in a chink of the sandstone rock,
whilst their upper or anterior parts, fringed with tentacula, are
exposed, like the sunflower when its petals are expanded, to the
cheering rays of light. These are at present undisturbed. Here is
another group ; and of these several have made prize of some food,

175

brought within their reach by the graceful vibrations of their
tentacula. The crustaceans —whether they scented the dainty
morsels or not we cannot determine — have hurried to the spot in
order to appropriate as plunder what has been legitimately obtained
by others. Each prawn is helping himself, drawing the coveted
bits from the grasp of the helpless and disappointed zoophytes: and
see how he scampers off with both hands full to a place of retreat.
But look once more. You observe an anemone in the act of
swallowing a piece of decayed shell-fish — his mouth opens wider
and wider — and now the morsel has disappeared. Here is a prawn
just arrived — almost too late — he feels with his finger and thumb
about the lips of the closed mouth — there is apparently nothing for
him ; yet he seems to know what he is about ; — and true enough ;
for see how artistically, how professionally he introduces his hand
into the mouth of the anemone ! He will not be defeated. Nor
has he any compunction. He thrusts his hand down, and down,
and yet deeper still, into the very stomach of the animal. He has
actually got possession of every particle that had been swallowed ;
and now he is off with all possible speed lest his ill-gotten booty
should be snatched from him by a prawn more valiant than himself.
This colony of plundered zoophytes is formed by a species of
anemone common only on certain parts of the coast — it is the
Actinia lellis, described by naturalists. It sometimes escapes de-
tection from the fact, that almost the whole body is often concealed
within the chink of a rock, whilst the expanded disc and the sur-
rounding tentacula are partially obscured by the shade of adjacent
sea weeds. It assumes a variety of shapes ; it can change its locality
at pleasure ; and, having apparently an aversion to the solitary life?
it is usually found in clusters of perhaps a dozen or more individuals
huddled together in close compact. The species can scarcely be
mistaken. In the same pool are other species of the same genus.
The most abundant of all the anemones, Actinia mesembryanthemwn,
is seen on all sides. It inhabits nearly every place at the sea side-
adhering to stones or to the sides of piers, and is easily recognized,
either as a gelatinous rounded body, not unlike a ripe cherry, when
closed during the recess of the tide, or, when in the full enjoy-
ment of the returning waters, it exhibits the form of the flower from
which its name has been derived. A careful examination of some of
the deeper pools in this neighbourhood will probably expose to view
very fine specimens of the larger species — Actinia coriacea, and
Actinia crassicornis. The former of these is abundant on many
parts of the shore, sometimes buried in the sand, and gregarious, or

176

hidden under fragments of rock between the tide marks, or in the
possession of a luxuriant pool. It may be known by the following
characters : — body conoid, or wider at the base than above ; skin
opaque, coriaceous, or leathery, covered with warts, variously coloured,
but usually dull red ; tentacula numerous, in three or four series, and,
when expanded, marked with rings. The other species, A. crassicornis,
although commonly found attached to shells or stones in deep water,
may often be obtained in rock crevices, at low water during the
spring tides, or even in the large pools. It may be procured at
Corriegills, or among the rocks at the south-east side of Holy
Island. It resembles A. coriacea in shape ; but it is a finer species ;
it grows to a larger size, it is less coriaceous, and more vivid in its
colours. It is a handsome object for the aqua-vivarium, where, after
a short period, it will be observed that the body becomes filled with
water, so as to be greatly enlarged and diaphanous, or almost trans-
parent; the tentacula, at the same time, are elongated, increase
their diameter, and exhibit their tubular form. This diaphanous
appearance is perhaps the most striking character by which it is dis-
tinguished from A. coriacea. It will add considerably to the interest
of the vivarium — provided the tank can afford accommodation — if
three or four individuals of this fine species are placed artistically
among the rock- work ; for, by a careful selection, specimens may be
introduced of variegated hues, some of cream colour, some of scarlet,
some of saffron, with orange stripes, or marbled with red and white.
There are, indeed, certain people who entertain other ideas as to the
proper destination of Actinia crassicornis. " For, of all kinds of sea
anemones," says Dicquemare,* " I would prefer this for the table; —
being boiled some time in sea water, they acquire a firm and palat-
able consistence, and may then be eaten with any kind of sauce.
They are of an inviting appearance, of a light shivering texture, and
of a soft white and reddish hue. Their smell is not unlike that of
a warm crab or lobster." But whatever importance the epicure may
attach to the above information, the sea-side visitor will do well to
watch the manoeuvres by which the anemones are themselves enabled
to gratify their tastes by a variety of dishes. It is most amusing to
observe the apparent cleverness — the agility and artifice exercised by
these curious creatures for the capture of their food. "On one
occasion," says Mr. Couch, " while watching a specimen (A. coriacea)
that was covered merely by a rim of water, a bee, wandering near,
darted through the water to the mouth of the animal, evidently
mistaking the creature for a flower, and, though it struggled a great
* Johnston's British Zoophytes, vol. L, p. 227.

177

deal to get free, was retained, until it was drowned, and was then
swallowed."* They are at once the most abstemious and the most
gormandizing of animated beings. They will live without food for
upwards of a year, and yet they may be seen at all hours, and every day,
angling, as it were, with their tentacula, and catching crabs, prawns,
limpets, periwinkles, dog-whelks, small fish, and, in short, whatever,
in the shape of fish, flesh, or fowl is brought within their reach.
They retain their food for ten or twelve hours, and then eject from
the stomach the well picked bones — the emptied shells of the
crustaceans and mollusca. Occasionally a bone will stick in the
throat. " I had once brought me a specimen of A. crassicornis that
might have been originally two inches in diameter, and that had
somehow contrived to swallow a valve of Pecten maximus of the size
of an ordinary saucer. The shell, fixed within the stomach, was so
placed as to divide it completely into two halves, so that the body,
stretched tensely over, had become thin and flattened like a pancake.
All communication between the inferior portion of the stomach and
the mouth was of course prevented, yet instead of emaciating and dying
of an atrophy, the animal had availed itself of what undoubtedly had
been a very untoward accident, to increase its enjoyments and its
chances of double fare. A new mouth, furnished with two rows of
numerous tentacula, was opened up on what had been the base, and
led to the under stomach : — the individual had indeed become a
sort of Siamese twin, but with greater intimacy and extent in its
unions.' 'f Another remarkable character in the natural history of
the Actiniae is, that, though impatient of ill-treatment under certain
conditions, as when torn abruptly from their attachment to the rock,
or when confined in water not sufficiently pure, they are almost
indestructible by the usual methods of destruction. " They may be
immersed in water, hot enough" says Dr. Johnston, "to blister
their skin, or frozen in a mass of ice and again thawed ; and they
may be placed within the exhausted receiver of the air-pump,
without being deprived of life, or disabled from resuming their usual
functions when placed in a favourable situation. If the tentacula
are clipped off they soon begin to bud anew, and if again cut away
they grow again." { The finer specimens of these two species, as
found in this locality, will occasionally measure from four to six
inches across.

110. With the exception of the above examples, the coast line
of Arran is not prolific in a variety of zoophytes. A few other forms

* Johnston's British Zoophytes, vol. i., p. 225.

t Ibid, p. 235. t MM, P- 239.

178

may be procured in deep water by means of the naturalist's
dredge. There are, however, two more species that will possibly
attract the attention of the inquisitive rambler along the shore : they
belong to genera closely allied to Actinia, viz., Anthea cereus, and
Adamsia palliata. The former frequently chooses for its position the
leaves of the grass wrack, or sea grass (Zostera marina), extensive
beds of which constitute submarine meadows in sandy districts. This
wrack (including the other species, Z. nana,) is the only instance of
a British flowering plant that lives in the sea. Now, wherever there
is a bed of this plant, the student of marine zoology (and also the
algologist, or marine botanist,) may pause and examine ; and, if he
does not object to wade knee deep, at ebb-tide, he will almost to a
certainty be repaid for his trouble. Large numbers of creatures
revel and thrive in this forest — fish, crabs, shell-fish, annelids or sea
worms, and zoophytes ; and here, dependent from the long riband-
like leaves of the zostera, you may often discover Anthea cereus with
his lengthened tentacula, on the look-out for his prey. The follow-
ing characters will be sufficient for identification : — body cylindrical,
smooth, adhering by a broad base ; tentacles numerous, longer than
the body, and, unlike those of the Actiniae, these arms cannot be
retracted, or are scarcely retractible, into the body of the animal,
It attains in this neighbourhood the size of about three inches,
measured from the base to the oral disc, or mouth ; — and it is of a
light brown, or dull ash colour. Beds of the Zostera marina occur
at Lamlash, on the sandy shore opposite the village ; also, on Holy
Island, not far from St. Molios's cave ; but, even where the sea wrack
does not grow, Anthea cereus may be found attached to one of the
commonest of our sea-weeds — Fucus serratus. The other species
-—Adamsia palliata — will not so readily be discovered by the casual
visitor, for it prefers the deep water. The dredge, when let down to
ten or twenty fathoms, will often bring up a dozen specimens at a
time. This zoophyte may be grouped among the most curious of
creatures. It will be sure, when once seen, to arrest attention.
Its habitat, or dwelling-place, is the exterior wall of a deserted shell,
as, for example, the dead shell of a buccinum, or whelk, or of a
trochus, or fusus, over the greater part of which the animal is
extended as a flattened mass about three-tenths of an inch in thick-
ness, varying from a light brown to cream colour, and having the
whole surface of its body streaked and spotted. The situation of
the oral disc is distinguished by three or four rows of tentacula,
short and white, forming an oval margin round the mouth. A thin
substance, like horn, will be observed covering part of the empty

179

shell, to which horny material the body of the Adamsia is attached ;
and, when excited, apparently by pleasure, as with feeding, it emits
long filaments, like white threads or delicate silken cords. But a
singular circumstance has yet to be mentioned: — The dead shell, over
which this zoophyte is spread, is generally inhabited by a hermit
crab, and always, as is supposed, by the same species, viz., Pagurus
Prideauxii. It is exceedingly curious to watch how advantageously
to both parties the arrangement works. Of course the Adamsia,
without any fatigue or effort, is carried by the roaming propensities
of the crab over a large district ; and, in this way, he commands an
extensive market for the acquisition of food ; whereas the Actinise,
being fixed to rocks or half buried in the sands, must either under-
take a slow and wearisome journey, by their own unassisted labour,
or be satisfied with the supplies brought by the wind or tide within
reach of their feelers. The hermit, on the other hand, is also re-
compensed; for, as the writer of these notices has frequently observed,
the palatable morsels secured by the tentacles of the zoophyte
are instantly seized by the claws of his crustacean companion, and
without any apparent apology or subsequent remorse, are partly
appropriated to his own immediate use. " In all likelihood," says
the late Rev. Dr. Landsborough, " they in various ways aid each
other. The hermit has strong claws, and while he is feasting on
the prey he has caught, many spare crumbs may fall to the share
of his gentle-looking companion. But soft and gentle-looking
though the Actinia be, she has a hundred hands, and woe to the
wandering wight who comes within the reach of one of them ; for
all the others are instantly brought to its aid, and the hermit may
soon find that he is more than compensated for the crumbs that fell
from his own booty."* Specimens of this curious and beautiful
zoophyte may occasionally be procured by a search in the zostera
beds at Lamlash, or in other places at low water. Dr. Lands-
borough first saw it at the mouth of the Glen Rosa burn, in
Brodick bay.

111. We must now inquire about the prawn captured at Corriegills.
Look at it through the sides of the glass vessel. The creature is
almost transparent. This is Palcemon Squilla; it is smaller than
the common prawn, Palcemon serratus, and differs in a few other
points from that species. It is readily found in the rock pools on Holy
Island, on both sides of Brodick bay, and indeed almost everywhere
on the Arran shore and on the Ayrshire coast. It is an interesting
object for the vivarium, both on account of its general appearance,
* Landsborough's Popular History of British Zoophytes, p. 230.

180

and from its activity in plundering the sea anemones. Other
crustaceans abound in this district. The numerous rocks are
places of retreat and shelter for the common edible crab, Canc&r
Pagurus, which, in moderate size, is caught in the creels by
local fishermen, whilst the younger individuals of this species may
be recognized scampering about the shore in search of food, or
hiding themselves under stones, in the enjoyment of a siesta. The
common shore or harbour crab, Cardnus Manas, inhabits the same
localities, and may be seen anywhere, or everywhere, in pools,
under sea-weeds, beneath rocks, or in the sands. Turn over the
stones, and another species will invite inspection — Porcellana platy-
cheles — distinguished at once from every other crab by the breadth
of its hands. But, of all the crustaceans, the hermit crab, already
mentioned in connection with an associated zoophyte, seems to
afford the most amusement to the sea-side rambler. There are
several species of this singular crab inhabiting deep water ; but the
most common kind, Pagurus Bernhardus, may be procured in any
quantity by strolling along the shore. The peculiarities of these
hermits are of no mean order. Each individual resides, hermit-
like, solitary, in a shell, which, either by fair or foul means, is
obtained and appropriated for self-protection. Nature has been
considerate in supplying a shield (the carapace) that entirely de-
fends every species of crab, except the genus now under our notice,
viz., Pagurus, which, whilst tolerably safe as to the head and
thorax, is in constant danger from the utterly unprotected state of
the posterior portions. The abdomen and tail are without the usual
covering of a coat of lime ; — they have no shell in these parts, and,
consequently, at any moment they might be at the mercy of
a hungry neighbour or spiteful antagonist. But here, as elsewhere
in the wonderful economy of Nature, the animal finds compensa-
tion for the deficiency, either in the use of its instinct, or rather,
perhaps, in the exercise of good sense, by which a remedy is provided
equal to its necessities. Its usual habit is to take possession of
the empty shell of a dead shell-fish — one of the univalves, such as
the common whelk — and, introducing the whole of its soft parts
into this cherished prize, it hooks its tail round the innermost whorl
of the shell, and, keeping both eyes and claws ready for action, it
bids a hearty defiance to every opponent. You may seize the
exposed claws and tear the hermits into pieces ; but, so apprehen-
sive are they of danger, and so tenaciously do they cling to their
support, you will seldom either persuade or force the creatures
to come out of their abodes. It is equally curious to observe

181

the cleverness shown when required to meet another difficulty. A
young hermit occupies a small house. This is a necessary con-
clusion, inasmuch as the shell has to be dragged about by its
occupant. But juvenile hermit crabs, like other young creatures,
increase in size, and, as they grow, they find that the abodes
selected in their youth have become inconveniently small ; for, of
course, the dead shells cannot be enlarged for their accommodation.
This embarrassment is easily obviated. It is merely a matter of
change of residence. You will see the hermit — if you watch on the
sea shore, and happen to be in the right place, at the right time —
bring himself into close proximity to a shell, empty, and larger than
the one then in his possession. His next step is to take an accurate
survey on all sides, to see that the coast is clear, and to make sure
that he can move from one house to the other without the risk of
a disadvantageous encounter with an enemy. It is the work of a
moment, provided that the new house proves to be more com-
modious than the old one ; but it sometimes happens that the crab
is mistaken in his calculation, and, in this case, it is most amusing
to watch our friend running about, half naked, and half frightened,
among a group of deserted shells, poking its tail first into one
and then into another, twisting itself in various directions, and
assuming different attitudes, in order to test the suitability of
the proposed arrangement ; and, finally, when fitted to its entire
satisfaction, it walks off, evidently pleased with its success, and
generously leaves the old shell for the accommodation of any future
house hunter less corpulent than itself. Not unfrequently two
hermits will meet and dispute the possession of a vacant shell.
Arbitration is never sought in these cases. It is simply a contest
between the two for mastery — a trial of physical power — and, where
the combatants are well matched, the conflict is generally of a fatal
character ; for the possession of a convenient house is considered of
such vital importance that the one or the other is determined to
obtain the coveted shell, and, at all times pugnacious, each is resolved
to die rather than yield ingloriously to its opponent. This sea-fight
often occurs. The slain are not a few. Sometimes a less serious
encounter may be witnessed, as when might exercises its too frequent
tyranny over right. The following incident affords a good illustra-
tion:— Two hermits met, accidentally, it may be supposed, within
the vivarium on Holy Island. The one was somewhat stouter than
the other ; and the weaker brother, appearing at first sight to
possess the larger house, received an immediate summons to turn
out and vacate his premises. The summons was disputed, a furious

182

combat commenced, and, after a variety of manoeuvres, with thrusts
and counter thrusts, the stronger, with a dexterous use of the hands,
seized the little fellow by both his wrists, and endeavoured to shake
him out, despite the opposition that was offered. The shells rattled
against the glass wall. It was a fierce engagement. At last the
older hermit, coming partly out of his shell, seemingly for the
purpose of obtaining a better purchase and a greater command of his
strength, pulled, and pulled, and pulled again — still drawing himself
farther out of his shell, as if he felt that the work was desperately
tough — until the youngster, giving way, stood, unhoused, discom-
fited, and embarrassed, to abide the good pleasure of his master.
The next scene was amusing enough. The conqueror came entirely
out of his house, and — retaining a firm grasp of his victim to
prevent him from bolting off with either of the two shells now
empty — backed himself into the new abode, just to inquire if it
would really prove a more convenient residence than his own, but,
disappointed in his anticipations, he returned to his former shell,
released his young friend without further detention or injury, and
apparently, with a polite "good morning," they separated, as if
nothing discourteous, or, at least, unusual had occurred.

112. The star-fishes will also afford interest during a ramble along
the shore. The most common species, Uraster rubens, is really too
common to be further noticed. Some kinds, as Palmipes membran-
aceus, Cribella rosea, Asterias aurantiaca, and others, can be pro-
cured only by the dredge ; but several of the deep water species
may occasionally be found by wading through the zostera beds at
Lamlash, or by examining the pools and rock crevices, especially
after a storm, on Holy Island. In this way, Luidia fragillissima,
Uraster glacialis, Cribella oculata, Goniaster Templetoni, Solaster
papposa, with some of the species of Ophiocoma and Ophiura, may
be picked up without much trouble. In a few places, the smallest
of British star-fishes, Asterina gibbosa, may be obtained ; but good
eyes and some patience are required. Try the pools at the north
end of Holy Island ; also Clachland point, in Arran. Turn aside
the sea-weed ; and it may be, after considerable search and dis-
appointment— for this species is by no means abundant — you will
see the little creature, grayish in colour, and gibbose and angulated
in form, adhering to the side of the rock. In Lamlash bay,
Uraster glacialis is plentiful. It may often be observed, on a calm
day, when the water is as clear as crystal, directing its course among
the algae at the depth of 10 or 15 feet — the creature itself, perhaps,
two feet in length — and, on nearer inspection, you will distinguish

183

it at once from Uraster rubens by the spines situated on the back of
each ray. Care is needed in the preservation of this species, for it
has the knack of dislocating its arms under your most cautious
treatment. But the star-fish that has gained most notoriety from
the facility with which it can, apparently at pleasure, dismember
itself — nay, break itself into any number of fragments — and, vexa-
tiously enough, at the very moment when you think the animal is
deceased, and preserved uninjured, is Luidia fragillissima. The sub-
joined description is from the pen of the late Professor Edward.
Forbes : — " The first time I ever took one of these creatures I suc-
ceeded in getting it into the boat entire. Never having seen
one before, and quite unconscious of its suicidal powers, I spread
it out on a rowing bench, the better to admire its form and colours.
On attempting to remove it for preservation, to my horror and dis-
appointment I found only an assemblage of rejected members. My
conservative endeavours were all neutralized by its destructive exer-
tions ; and it is now badly represented in my cabinet by an armless
disk and a diskless arm. Next time I went to dredge on the same
spot, determined not to be cheated out of a specimen in such a way
a second time, I brought with me a bucket of cold fresh water, to
which article star-fishes have a great antipathy. As I expected, a
Luidia came up in the dredge — a most gorgeous specimen. As it
does not generally break up before it is raised above the surface of
the sea, cautiously and anxiously I sunk my bucket to a level with
the dredge's mouth, and proceeded in the most gentle manner to
introduce Luidia to the purer element. Whether the cold air was
too much for him, or the sight of the bucket too terrific, I know
not, but in a moment he proceeded to dissolve his corporation, and
at every mesh of the dredge his fragments were seen escaping. In
despair I grasped at the largest, and brought up the extremity of an
arm with its terminating eye, the spinous eyelid of which opened
and closed with something exceedingly like a wink of derision."*

Experience has since shown that the means by which either Lui-
dia, or Uraster glacialis can be secured for cabinet specimens is, not
to destroy them violently by plunging them into fresh water, but to
let them die by a more quiet process, viz., by leaving them in a ves-
sel of sea water until life is exhausted. Under these circumstances
they are not prone to break, and thereby disappoint their captors. t
Luidia will be recognized by its light orange or buff colour ; its rays

* British Star-fishes, page 138.

f Dr. Carpenter has found that, by placing Luidia in a pan of Glycerine, the crea-
tur3 dies at once, and without disfiguring itself.

184

are smooth on the back, and provided with spines on their margins ;
specimens measuring a foot may he picked up on the shore in Lam-
lash bay, and individuals of twice that size are procurable by the
dredge, or may sometimes be hooked up in shallower water with a
common rake. There is another singular creature of great interest
to the naturalist — it is Comatula rosacea, or the rosy-feathered star-
fish— a beautiful and elegant example of the radiated form of ani-
mated beings. It is found abundantly in Lamlash bay, near the
pier on Holy Island, and in other parts of the locality ; but the
dredge is required, as this species inhabits deep water — that is,
depths of about ten fathoms. At some seasons almost any number
may be obtained. They are brought up attached to the large sea-
weed, Laminaria saccharina, from which they must be removed with
care, as they are exceedingly brittle, and, like the Luidi®, can break
themselves into fragments with astonishing and unpleasant speed.
The best way, perhaps, to prepare dry specimens for the cabinet is
to treat them as the marine botanist treats the more delicate algae —
spread them on drawing paper, place over them a piece of smooth
linen, and let them dry between folds of blotting paper, under slight
pressure ; but, in the first instance, they must be allowed quietly to
die in sea water, or more rapidly in a solution of alum — for, if
immersed in pure fresh water, they will lose their beauty, by the
removal of their colouring matter. In order to appreciate the exqui-
site form and elegant movements of this star-fish, the creature must
be seen and watched in a vivarium, where it will voluntarily fix
itself to the sea- weed or to a piece of rock, and, by graceful undula-
tions of its arms, will be certain to command admiration. The
picture will be greatly enhanced if several individuals of various
colours — orange, purple, crimson — are introduced, and judiciously
dispersed.

113. Before we leave this division of the subject, it will suffice to
make brief mention of the well known sea hedgehog, Echinus sphcera,
common in most parts of the Clyde, and of which fine specimens are
found clinging to the rocks on Holy Island, and at Clachland Point.
This curious creature should be carefully examined by the young
student of marine zoology . It is allied to the star-fishes ; for although
spherical in form, the radiated structure is readily perceived. In
short, it is a star-fish, with the spaces between its rays filled up by
plates of carbonate of lime — the rays themselves consisting of the
same material — the whole exterior being bent over into a hollow
ball, and armed, hedgehog like, or like the star-fish Uraster glacialis,
with numerous sharp spines. The viscera, or digestive organs, of

185

the echinus are contained within the ball ; and its mouth is provided
with a beautiful piece of mechanism, worthy of examination, and
designed for crushing the shells of molluscous and crustaceous ani-
mals on which it feeds. Its mode of progression, by means of its
spines and suckers, is both interesting and wonderful. Specimens
are frequently found of the richest crimson or purple. Another
species of this genus, Echinus miliaris, is also common in the pools.
It is more diminutive than the former. The dredge will generally
be needed to obtain living specimens of the other forms of these
echinodermatous or radiated creatures — such as Spatanguspurpureus,
Echinocyamus pusttlus, and Amphidotus cordatus, or the common
Heart Urchin, of which the dead and empty shells, with their spines
rubbed off, may frequently be noticed washed up and left upon the

114. The study of another important division of animated nature
— the mollusca — has been a favourite pursuit of scientific men and of
amateur observers. To this division the marine shells belong. Here
the conchologist finds his delight in the examination and arrange-
ment of the materials of his department — admiring the endless
variety of form, and colour, and sculpture ; whilst the zoologist is
laboriously occupied in determining the anatomical structure of the
inlwhitants of the shells — tracing the peculiarities of the different
genera and species.

The waters around Arran produce a considerable number of shells ;
but, with few exceptions, the species are common to all parts of the
Clyde. The dredge is required to procure specimens of interest ; and
for the information of naturalists unacquainted with the district,
it may be stated, that the most profitable dredging ground, in Lam-
lash bay, lies between Hamilton Eock, near Clachland Point on
the Arran shore, and the north and north-east sides of Holy Island,
extending the whole way across, and in depths from fifteen to forty
fathoms. A full list of the species will be given at the end of these
notices ; but the following genera, as being found in this particular
locality, may be here mentioned: — Aporrhais, Artemis, Astarte,
Cardium, Cerithium, Ghemnitzia, Circe, Corbula, Crania, Cylichna,
Cyprcea, Cyprina, Dentaliwm, Emarginula, Eulima, Fissurella
FusuSj Kellia, Leda, Lima, Lyonsia, Mangelia, Modiola, Montacuta,
Nassa, Natica, Nucula, Odostomia, Pecten (including P. striatus
and P. tigrinus), Pectunculus, Philine, -Pileopsis, Pttidium, Psam-
mobia, Puncturella, Eissoa, Scalaria, Scaphander, Tellina, Tere-
bratula, Thracia, Trichotropis, Trochus, Turritella, and Venus.
Several of these genera occur also in other places in Lamlash bay,

2u

1SG

and round the coast. On the other hand, Brodick bay, Whiting
bay, and the vicinity of Pladda, have hitherto proved to be exceed-
ingly unprofitable. Loch Ranza, notwithstanding the apparent
advantage of its position, did not yield anything, after several hours
of active dredging in all parts of the bay, except the commonest
of the scallops, Pecten opercularis — an excellent bait for fishermen,
and which may be procured here in any quantity. The strait which
separates Arran from Argyllshire, known as Kilbrannan Sound, will
probably yield richer results than other parts of the Clyde ; but
these waters have not yet been sufficiently examined to warrant
more than a conjectural opinion. The south end, and the south-
east side, of Holy Island are also unprofitable.

It must not be expected that the rarer molluscous animals or shells
may be obtained from the pools, or from the sands, or rocks, forming
the coast-line. Yet an attentive investigation will not be without
its reward. In the vicinity of Clachland Point, where the excavated
sandstone affords numerous places of retreat, and where each return-
ing tide supplies the wants of the tenants, a variety of creatures may
be seen grouped together in quest of the enjoyments of life. Let
the crevices be carefully searched — turn over the fronds of the sea-
weeds— capsize the loose stones — look under the ledges of the rocks —
select a calm day, during the spring tide, when the water has ebbed
to the lowest — and there will not be any need, at least for the
young student, to complain of the result. A curious mollusc
inhabits this station — Aplysia, hybrida, or the sea hare, which
will be recognized, whilst in a state of activity, by the peculiar shape
of its antennae ; for these, when expanded, are something like the
erect ears of the common hare. Another mollusc, found upon the
shore, and not without pretensions to respect, as well from its lovely
orange colour, as from the gracefulness with which it moves, is the
Pleurobranchus, which, being nocturnal in its habits, may be caught
napping at the period most convenient to its captor. It is a good
object for the vivarium, where, lying concealed during the day, it
will be observed, at midnight, traversing the tank, like a solitary
watchman on his rounds ; but, unlike the guardian of our streets, its
purpose is — not to defend property, but to appropriate to its own use
without fear of detection, whatever it may regard as palatable to
its taste, or requisite for its necessities. Both the Pleiirobranchus
and the Aplysia may be procured from pools at the north end
of Holy Island. At Lamlash, in the neighbourhood of the old
quay, the blocks of sandstone, which He scattered in all directions,
contain, here and there, good specimens of one of the bor&rs — a

187

division of the mollusca, whose habit is to penetrate either sand, as
the common cockle, Cardium edule — or wood, as the different species
of Teredo— or stone, as the genus Pholas, a bivalve, of which the shell
in some species is extremely fragile, and although wonderfully well
adapted to its work as an excavator of solid rocks, requires the utmost
caution when being handled in our collections. The species that
bores through the sandstones at Lamlash is Pholas crispata. The
wood-borer, Teredo navalis, is common in many parts of the Clyde, as
may be proved by witnessing its destructive operations at Ardrossan
and Fairlie on the Ayrshire side, where also its ally, Xylophaga,
dorsalis, has done its full share of mischief. Another species, less
common, and of larger growth — formerly unknown, as is supposed,
higher up the Clyde than Port Patrick, viz., Teredo Norvegica,
introduced itself into Lamlash bay, and, during the short period of
about seven years, it had almost demolished the massive supports
of the pier — a commodious and substantial landing place, erected,
as the owner undoubtedly thought, for the convenience of himself
and friends. The Teredo, however, commenced and continued its
operations unnoticed — not one pile of the water-covered timber
escaped — the whole was pierced in lengths varying from a few inches
to about two feet, when, in the hurricane of February, 1856, a vessel
was driven upon the spot, and almost the entire structure was swept
away.* On an examination of the fragments thrown upon the
island, several specimens of the calcareous tube, formed by the animal
in the course of its progress, and a few of the valves, were secured
for private cabinets ; and pieces of the bored timber were given to
the museums of Glasgow College and of the Andersonian University.
The most abundant species of Trochus on these western shores
is T. umbilicatus, which, with T. dnerarius and T. tumidus, may
be procured in any quantity on Holy Island. Here also the following
shells are not uncommon: — Acincea testudinalis, Kellia rubra — a
minute bivalve attached to the dark low growing plant, Lichina
pygmcea, which overspreads the rocks near the sea ; — Patella athletica,
P. pellucida, Tapes decussata, with different species of Littorina,
and other equally common and widely diffused forms. In the
sands, at Lamlash, at low water, Mactra solida, and M . subtruncata,
are plentiful. But, leaving the coast line, and letting the dredge
drop in about ten fathoms, at the north end of Holy Island, or
between the north point of the island and the pier, a peculiarly
interesting shell may be collected in large quantities — Lima hians,

* This pier was built by the late Mr. Oswald, member for the city of Glasgow.

188

the inhabitant of which constructs and occupies a nest. The shell
is of delicate texture, and, when deprived of extraneous matter by
careful washing, is entirely white, and, being graceful in form, is an
acquisition to an ornamental cabinet. It is desirable, however, to
preserve specimens of the nest as well as of the shell, and to allow
both to remain, as far as possible, in their natural position. The
nest is formed of materials collected at the bottom of the sea —
cither pebbles, or broken shells, or both shells and pebbles — and
these are brought into a mass and bound together by a glutinous
thread secreted by the animal. Sometimes the Lima is solitary —
having built a house simply for itself; but, generally in Lamlash
bay, the dredge brings up large patches of this compacted debris,
in which will be found a colony living in apparent comfort, security,
and friendship — each individual, however, having a separate and
snug berth. A supply of specimens may be secured in a few
moments. The animal is also a beautiful object in the water —
its numerous tentacula, which extend beyond the limits of its
shell, are of a fine orange colour, and, being a bivalve, it moves from
place to place with ease and agility, by the rapid opening and closing
of its valves. Although rare in many localities, Lima hians has an
extensive range in the Clyde — the nests being found off the coast of
Islay, between Largs and the Cumbraes, and on the Argyllshire
side, as high up as Hunter's Quay, Dunoon. But the station where
it is really abundant is Lamlash bay, where also the other species,
L. loscombii, and L. subauriculata, may be procured.

115. Although many objects of interest have now been mentioned,
there remain a considerable number of living creatures, more or less
wonderful both in structure and in habit, which, from various causes,
have not yet been sufficiently examined on this coast ; and, conse-
quently, any information respecting them must necessarily be meagre.
Among the Annelids, or sea-worms, the following genera are known
to belong to Lamlash bay: — Aphrodita, Arenicola, Eunice, Ner&is,
Pectinaria, S&rpula, iSjnrorbis, Terebella. The young student will
be usefully employed in the search and study of these curious forms
of life, for, notwithstanding that they take no higher rank than
worms, they exhibit, in some species, characteristics so peculiar, and
colours so gorgeous, as to attract even the popular eye and to excite
unsparing admiration. Who is not familiar with the Serpulce,
whose heads are crowned with radiating threads of varied hue ?
These singular tufts, which the animal protrudes for health and
pleasure, and which, with the rapidity of thought, are withdrawn
into its calcareous tube on the first symptom of alarm, are its gills,

180

or organs of respiration. Let the shadow of your hand pass near
the side of a glass vessel, in which a living specimen is contained,
and instantly the head starts back into concealment ; but watch,
and in a few moments its brilliant coronet will reappear. The
Pectinaria resides in a house made of the finest sand cemented in
the form of a tapering tube ; and its gills, in shape like a minute
comb, are as bright as burnished gold. In the Terebellce, inhabitants
of mud, the numerous and long worm-like tentacles present the
appearance of so many separate Annelids entwined around their
common prey. The genus Eunice occupies a tube composed of a
substance not unlike thin horn or the slender quill of a bird. The
spiral white spots frequently spread over tangle or other large
sea-weeds are examples of Spirorbis. The sea-mouse, Aphrodita
awdeata, obtained with the dredge, will easily be recognized by the
metallic lustre of its long bristles, which, partially covering the
animal, give out the colours of the rainbow. Some of the marine
worms are remarkable from the enormous length to which their
thread-like bodies are extended. Another class of widely diffused
beings, not yet sufficiently investigated on the Arran shores, and
which, like the Annelids, are worthy of a more honourable name
than is assigned to them in popular language, are — the Sea slugs,
known in scientific phraseology, as the Nudibranchiate mollusca.
These are within the reach of every observer — for, at low water,
they may be seen reposing under loose stones or adhering to Alg<z.
Some of the species, especially of the genus Eolis, are really charming
objects — elegant in form, and beauteous in colour. They cannot
be mistaken. Place a specimen in a tumbler of sea water,
it will unfold itself, and its gills, differently situated in different
species, will be seen expanding into full operation as the little
creature pursues its journey round the sides of the vessel. It
enjoys the learned appellation of Nudibranch, because its branchice,
or breathing organs, are naked, or exterior to the body of the
animal. The genera Doris, Eolis, Goniodoris, 1/omanotus, Poly-
cera, and Triopa, have been found in the bays of Brodick and
Lamlash ; but, if an active search be made, the number of ascertained
species will doubtless be greatly augmented, and the labourers in
this department will be amply rewarded. Nor must we altogether
overlook, as among the more remarkable forms, the Acalepha,
to which the Medusae and other Jelly-fish or Sea-nettles belong.
Some of the larger and coarser species are familiar to sea-bathers
by the stinging qualities of their tentacula. But there are other
species a? harmless as they are lovely. On a calm summer day,

190

when there is not a ripple to disturb the sea, these exquisitely
formed creatures may be witnessed in hundreds, like a vast fleet of
fairy ships, lying upon the surface. Such are the Beroe and the
Cydippe. Let specimens, captured carefully in a gauze net, be
transferred to a vessel of water, and, low as they are in organization,
they will not be dismissed without commanding surprise at the
delicacy of their structure and at the facility with which they
traverse their allotted space.

116. It remains only to add, after the above general view of inverte-
brate life, that in the various bays and inlets around Arran, almost
every kind of fish, common to our northern seas may be procured.
It would be superfluous to name the species familiar to every person.
But we must not omit to mention that the Lancelet — Amphioxus
lanceolatus — has been dredged at the north end of Holy Island,
where it seems to be restricted to a gravel bottom in depths of about
ten or fifteen fathoms. Until recently this fish was regarded as
extremely rare. It is now, however, known to be more common.
Several specimens have been captured near Millport, in the island of
Cumbrae, as well as in Lamlash bay; and, probably, it will be
discovered to have a wider range than at one time was expected.
The interest attached to it arises from its anatomical and physio-
logical peculiarities. Its spine is a cartilaginous thread-like column,
without joints ; it has no ribs, no pectoral or ventral fins ; and, in
short, although claiming rank with vertebrate animals, the skeleton
is rudimentary and the brain absent. The Amphioxus is an excellent
illustration of the law that, even where there is the greatest departure
from uniformity, the typical characters are rigidly preserved in the
development of creation.

117. In concluding our notices of the marine zoology of Arran,
the subjoined tables may advantageously be added for the informa-
tion of naturalists not practically acquainted with the Fauna of
the Clyde. The species marked with an asterisk were dredged
by the late Rev. Dr. Landsborough and Major Martin ; and
the other species were obtained by Dr. Greville and myself in
our examination of this part of the coast. The list, so far as com-
pleted without the assistance of the former gentlemen, appears in
the Annual Eeport of the British Association for the Advancement
of Science for the year 1856. Dr. Landsborough and Major Martin
were indefatigable in their investigation of these localities. There
yet remains, however, much work to be accomplished by future
inquirers — especially among some of the remarkable groups, as the
Cirripeda, Annelida, Acalepha, Zoophyta, and Poriphora — as also

191

among the Polyzoa and microscopic forms included in the Infusoria
and Rhizopoda.

TABLE I.— MOLLUSC A.

*Aclis nitidissima, .

unica,

Acmsea testudinalis,

— virginea, .
*Adeorbis sub-carinata, .
*Amphysphyra hyalina, .

Anomia ephippium,

aculeata, .

Aplysia hybrida, .

Aporrhais pes-pelicani,
*Arca lactea, V .' ,

Artemis exoleta, .
- lincta,

Astarte compressa,

* elliptica, .

* Scotica, .

sulcata, .

Buccinum undatum,
*Coecum glabrum, .
* trachea, .

Cardium echinatum,

edule,

* fasciatum,

* nodosum,

Norvegicum, .

* Suecicum,

*Cerithiopsis tubercularis,
*Cerithium adversum, .

reticulatum, .

Chiton asellus,

marmoreus,

ruber,

*Chemnitzia indistincta,

* rufescens, .

Circe minima,
Corbula nucleus, .

Crania anomala, .

*Crenella decussata,

* discors, .

* marmorata,

Cylichna cylindracea, .
* — — mammillata, .

* obtusa,

* truncata,

* umbilicata, .

Cyprsea Europaea,
Cyprina islandica,
Dentalium entalis,
*Donax anatinus, .
Emararinula reticulata, .

The whole of the shells named in this
table were dredged in Lamlash

. Bay, — the best ground being the
area that extends from Clachland
Point and Hamilton Rock to the
north end of Holy Island, in from
15 to 40 fathoms.

In the pools, Clachland Point.

\ Scarce in Lamlash Bay.

f Attached to stones and shells in deep
.< water, — not scarce in Lamlash
( Bay.

Dead shells not uncommon.

192

Eulima bilineata, .

distorta, .

* polita,

Fissurella reticulata,
Fusus antiquus, .
• islandicus, .

Kellia rubra,

suborbicularis,

*Lacuna pallidula,
* — — vincta,

Lamellaria perspicua,
*Leda caudata,
*Lepton convexum,

Lima hians, .

loscombii, .

subauriculata,

Littorina littoralis,

littorea,

neritoides,

— — rudis, .

*Lucina flexuosa, .

* spinifera, .

*Lucinopsis undata,
*Lutraria elliptica,

Lyonsia Norvegica,

Mactra elliptica, .

solida,

stultorum,

subtruncata,

Mangelia costata,

Leufroyi,

* linearis,

* nebula,

rufa, var. Ulideana,

* septangularis,

JL TJGrGSj • • •

* turricula,

Modiola modiolus,
* phaseolina,

*Montacuta bidentata, .

substriata,

*Mya arenaria,

* truncata,

Mytilus edulis,
Nassa incrassata, .

reticulata, .

*Natica alderi,

monilifera,

Montagui,

*Nucula nitida,
*< nucleus, .

. 1 Good specimens from gravel bottom,
. v at about 15 fathoms, north end of
. ) Holy Island.

f Concealed in the plant Lichina
< pigmcea, near the shore, Holy
I Island.
In different parts of Lamlash Bay.

"At the north end of Holy Island, in
about 10 or 15 fathoms. The
nests of Lima hians, with the live
shells, are very abundant in this
locality ; and they are worth

^ examining for Diatomacece.

>In the sands, low water, Lamlash.

In deep water between Clachland

Point and Holy Island.
•M. Rufa was dredged between

Fullarton's Rock and King's

Cross Point.

( Attached to the spines of Spatanyus
\ purpureus.

Immature specimens everywhere.

193

/ An oyster-bed, Lamlash Bay, Holy
I Island.

Holy Island.

•Lamlash Bay.

*Nucula radiata, .
*Odostomia conoidea,

* cylindrica, .

* decussata, .

* excavata, .

* interstincta,

* plicata,

* — • rissoides,

* spiralis,

* unidentata, .

Ostrea edulis, . . • .

*Ovulum acuminatum, .
Patella athletica, .

pellucida,

vulgata, .

Pecten maximus,

• opercularis,

* pusio,

— similis,

striatus, .

' tigrinus, .

* varius, . . .

Pectunculus glycimeris,

Philine aperta,
*— — catena,
* scabra, . . .

Pholas crispata, .

Pileopsis Hungaricus, .
Pilidium fulvum, ....
*Pinna pectinata,*

Pleurobranchus membranaceus (?) Under stones, low water, Holy Island.
*Pleurotoma gracilis,

* septangularis,

Psammobia Ferroensis, ' .
Puncturella Noachina, .
Purpura lapillus, ....
*Rissoa Beanii, .
*• calathus, ....

* cingillus, ....

*-— — — costata, ....
costulata, ....
crenulata,

fulgida, ....
inconspicua, . . *
interrupta,
labiosa,

parva, ....
punctura, , . ...
rubra, . . . *
rufilabris,
semistriata, . .; .

* Pinna pectinata was also dredged by the late Major Martin on Skelmorlie Bank,
near Wemyss Bay, Ayrshire coast.

2c

I In the sandstones, low water, Lam-
1 lash.

194

Rissoa striata, ....

striatula, ....

* ulvae, ....

*-— — vitrea, ....

* Zetlandica,

*Saxicava arctica, ....
*-_- rngoea, . . . .
*Scalana communis,

Scaphander lignarius, .
*Skenea divisa, ....

* nitidissima,

* planorbis,

*Sphoenia Binghami,
•Syndosmya prismatica,

Tapes aurea, ....

— decussata, ....

virginea, ....

*Tellina crassa, ....

donacina,

* fabula, ....

* incarnata, . . .

* solidula, . . . .

* tenuis, ....

m v , i , • ( Deep water, between Hamilton

Terebratula caput-serpentis, . J Rnok , jr. Tql ,

Lamlash Bay. T. umbilicatus is
common along the shore of Holy
Island, also T, cinerarius.

•Teredo megotara,

Norvegica, . . { ^fc^a™** °f ^ pier' Holy

Thracia phaseolina,
* pubescens,

Trichotropis borealis,

Trochus cmerarius,

magus, .

millegranus,

Montagui,

pusUlus, .

tumidus,

umbilicatus,

undulatus,

ziziphiuus,

*Trophon Barvicensis,
* clathratus,

Turritella communis,
*Turtonia minuta,

Venus casina,

fasciata,

gallina,

ovata,

striatula,

North end of Holy Island, in from
10 to 20 fathoms.

TABLE n.— NUDIBBANCHIATE MOLLUSCA.

Doris bilameUata, 1 Under stonesj at low water' ^ man?

planata U Piaces» and not uncommon. D.

' \ planata, was found in Lamlash

tuberculata . na JasAun

J Bay by Mr. Alder.

195

*Eolis alba, ....
* coronata,

Drummondi,

* Landsburgii,

Goniodoris nodosa,

Lomanotus (?)

— flavidus,

Polycera quadrilineata,
Triopa claviger, . . .

Under stones at low water, in many
places, and not uncommon.

Probably a new species, dredged in
Brodick Bay by Dr. GreviUe and
Dr. Miles, in about 15 fathoms,
between Invercloy and Corriegills,
but the specimen was unfortu-
nately lost before it could be sent
to Mr. Alder for examination.
It was two inches in length, white,
with orange processes, and of rare
beauty. A sketch taken by Dr.
Greville was forwarded to Mr.
Alder. L. flavidm was dredged
in 1846 by Mr. Alder in Lamlash
Bay.

TABLE IIL—CRUSTACEA.

Balanus balanoides,

Cancer Pagurus, .
Carcinus Moenas, .
•Ebalia Bryerii,

* Cranchii, .

— Pennantii,

Eurynome aspera,
Galathea squamifera (?)
Gonoplax angulata,
Hippolyte varians,

Homarus vulgaris,

Hyas araneus,

* coarctatus, .

Inachus Dorsettensis, .

Lithodes Maia, .
Pagurus Bernhardus,

Prideauxii,

Palaemon squilla, .
Palinurus vulgaris,
Pandalus annulicornis,

The Cirripedia have scarcely been

examined.

The edible crab is common around
\ Arran.

Dredged by Dr. Greville in Lamlash
Bay.

. Not uncommon in deep water.

( Several specimens obtained from
' \ deep water, Lamlash Bay.

On the Ayrshire coast, abreast of
Arran.

i The common lobster is found among

./ the rocks on different parts of the

( Arran coast and at Holy Island.

Found in Lamlash Bay on floating
wreck.

in deep water, mid-channel, off
Arran.

Abundant everywhere.
C Abundant in Lamlash Bay, with
\ Adamsia palliata.

Common in all the rock-pools.
C Obtained by the late Major Martin
\ from off Campbelton.

196

"Pinnotheres pisum,

Porcellana longicornis, . . Among the roots of Laminaria.

, , , , f Abundant under stones at low water,
platycheles, . . | Holy Igland and Lamlash<

Stenorhynchus phalangium, . . Dredged in deep water.

TABLE IV. — ECHINODERMATA.

Amphidotus cordatus, . . . The following species were all ob-
roseus, . . . tained in Lamlash Bay.

Asterias aurantiaca, . . . Near Fullarton's Rock.
Asterina gibbosa,
Chirodota digitata,

Asterina gibbosa, . . . In pools, north end of Holy Island,&c.

Dredged near the pier, Holy Island.

Abundant in Lamlash Bay, near
Holy Island, in from 8 to 15

Comatula rosacea, . . .-^ fathoms. Solitary individuals have

been traced up the Clyde as high
as Hunter's Quay, Dunoon.

Cribella oculata, .

fThis beautiful star-fish (two speci-

rosea, . . . . < mens) was dredged in deep water,

t north end of Holy Island.

Echynocyamus pusillus,

Echinus miliaris, .

sphcera, ....

Goniaster Templetoni, . . Not uncommon hi the Bay.

Luidia fragilissima, . . . Not uncommon in the Bay.

Ophiocoma bellis,

granulata,

rosula,

Ophiura texturata,

Palmipes .embranaceus, .' { G°£^™^ ™to' ™

Sipunculus • (?)

Spatangus purpureus, .
Solaster papposa,

Uraster glacialis, ....
— — rubens, ....

TABLE V. — ZOOPHYTA.
Actinia bellis, . . . .In the rock-pools, not uncommon.

n^cratico™;;, : : :y^^*;^*j«M*

mesembryanthemum,

( Abundant in Lamlash Bay, attached
Adamsia palliata, . . . < to shells occupied by Pagurus

{ Prideauxii.

Anthea cereus, ....
Antennularia antennina,

* ramosa, .

Cellepora pumicosa,

• ramulosa,

Skenei,

Campanula™ dumosa,

Flustra foliacea, . . . .

Halecium halecinum, .

197

•Halichondria panicea,
• suberea,

Laomedea geniculata,

Lepralia annulata,

hyalina, .

Malusii, .

Peachii,

trispinosa,

violacea, var. cruenta,

Plumularia pinnata,

Salicornaria farciminoides,

Sertularia tamarisca, .

. {On stones and dead shells, in deep
• j water, Lamlash Bay.

198

ENTOMOLOGY OF ARRAN

LEPIDOPTEEA.

118. AMONG the Lepidoptera, or tribe of butterflies and moths,
occurring in the Isle of Arran, are several of rather peculiar
interest ; and a work treating of the Fauna of Arran would be in-
complete without some notice of them.

COLIAS EDUSA (the clouded yellow butterfly) is a species which
is very seldom seen so far north ; but its occurrence near Lamlash
was chronicled in the Zoologist for 1848, p. 1985.

EBEBIA BLANDINA (the Scotch Argus) is a mountain species of
butterfly, which, though common in many northern localities, is
esteemed a prize by all collectors of the plains, when first they meet
with it. It is common on many of the hill-sides in Arran.

EBEBIA LIGEA is a species closely allied to BLANDINA, which has
been reported to occur in the Isle of Arran ; and Mr. Curtis, the
distinguished author of British Entomology, assured me that the
late Sir Patrick Walker told him he had himself taken it in the
island, in the second half of August. No recent captures of this
insect in Britain are known ; and the fact of its having ever been
caught here being much doubted, the species has ceased to figure
in our lists of indigenous species.

CCENONYMPHA DA VIES is common on boggy places at some
altitude above the sea.

Of the handsome genus of FBITILLABIES three species — ABGYNNIS
AGLAIA, ADIPPE, and SELENE — are by no means uncommon in the
little glens, up the hill-sides, and in early spring THECLA RUBI (the
green hair streak) is frequent amongst bramble bushes.

POLYOMMATTTS AflTAXEBXES is a species very likely to occur in
Arran, though I am not aware that it ever has been found there.

ANTHBOCEBA MINOS. — The recent capture near Oban of this
species of Sphinx, found three years ago in Ireland, renders it certainly
not improbable that it may occur in Arran. Like many of its con-
geners, it is excessively local, and may occur in some limited spot,
only on one hill-side, yet there be in profusion.

Among the family of the day-flying moths, the BOMBYCINA, none
of those which have been observed in the island are of sufficient
importance to deserve special notice.

199

Amongst the NOCTUINA, the pretty THYATIBA BATES (peach-
blossom) is common ; CELJENA HAWOETHII is tolerably plentiful;
HADENA ASSIMILIS has once or twice been taken on the face of
stone rocks; and PLTJSIA INTEBBOGATIONIS is rather common than
otherwise.

Amongst the GEOMETBINA which have been noticed here, may be
mentioned M^SIA BELGIABIA, which flies in heathy places ; OPOEABIA
FILIGEAMENAEIA, LAEENTiA CjGSiATA, SALICAEIA, and the moun-
tain species of the pretty little genus EMMELESIA, viz. : T^NIATA,
EEICETATA, and BLANDIATA, and the pretty insect CASSIA IMBTJ-
TATA, of which the Scotch specimens are so much more delicately
marked than those from the neighbourhood of Manchester.

Of the smaller species of Lepidoptera none of peculiar interest
have yet been noticed in Arran ; but it must be borne in mind that
this portion of its natural treasures has never been thoroughly
explored.

LIST OF LEPIDOPTERA COLLECTED IN 1836 BY DR. CONNELL:* —

Cynthia cardui. Hepialus velleda.

Hipparchia blandina. humuli.

— — polydama. Rumia crotsegata.

pamphilus. Ophiusa lusona.

hyperanthus. Leucania pallens.

janira. Plusia chrysitis.

semele. Episema coeruleocephala.

Polyommatus alsus. Leucania impura.

— — — Alexis. Larentia chenopodiata.

Vanessa urticse. Fidonia atomana.

Pontia brassicae. Cabera exanthemata.

rapae. pusaria.

napL Actebia porphyrea.

Melitisea Euphrosyne. Xylina putris.

Argynnis Aglaia. Harpalyce fulvata.

Lycasna phloeas. _— sylvatica.

Arctia caja. ocellata.

Cerura vinula. Margaritia verticaKs.

Macroglossa stellatarum. Botys forficalis.

Minoa choerophyllata. Anarta myrtilli.

Anthrocrea fflependuloe. Pterophorus punctidactylus.

Spilosoma menthastri. Nemeophila plantaginis.

Hypena proboscidalis. Plusia gamma.
Mamestra brassicae.

* This list contains all that has been published up tiU this time, regarding the
Entomology of Arran. It was furnished to Dr. Landsborough by the late Dr. Connell

of the High School of Glasgow; and was published first in the New Statistical

Account of Scotland, vol. v., and afterwards in Dr. Landsborough's Excursions to
Arran.

>i ^ ^T

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