Grant Allen - Science in Arcady

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SCIENCE IN ARCADY

BY

GRANT ALLEN

LONDON:
LAWRENCE & BULLEN,
16, HENRIETTA STREET, COVENT GARDEN, W.C. 1892.

To GRANT RICHARDS,
_IN GRATEFUL ACKNOWLEDGMENT OF MANY KIND OFFICES._

Avuncular Greeting.

CONTENTS.

PAGE

MY ISLANDS 1

TROPICAL EDUCATION 21

ON THE WINGS OF THE WIND 40

A DESERT FRUIT 56

PRETTY POLL 71

HIGH LIFE 90

EIGHT-LEGGED FRIENDS 105

MUD 123

THE GREENWOOD TREE 140

FISH AS FATHERS 157

AN ENGLISH SHIRE 177

THE BRONZE AXE 212

THE ISLE OF RUIM 231

A HILL-TOP STRONGHOLD 250

A PERSISTENT NATIONALITY 266

CASTERS AND CHESTERS 274

PREFACE.

These essays deal for the most part with Science in Arcady. 'Tis my
native country: for I am not of those who 'praise the busy town.' On
the contrary, in the words of the great poet who has just departed to
join Milton and Shelley in a place of high collateral glory, I 'love to
rail against it still,' with a naturalist's bitterness. For the town is
always dead and lifeless. There are who admire it, they say--poor
purblind creatures--because, forsooth, 'there is so much life there.'
So much life, indeed! No grass in the streets; no flowers in the lanes;
no beetles or butterflies on the dull stone pavements! Brick and mortar
have killed out all life over square miles of Middlesex. For myself, I
love better the densely-peopled fields than this human desert, this
beflagged and macadamised man-made solitude. The country teems with
life on every hand; a thousand different plants and flowers in the
spangled meadows; a thousand varied denizens of pond, and air, and
heath, and copses. Their ways are endless. They attract me far more
with their infinite diversity than the grey and gloomy haunts of the
cab-horse and the stock-broker.

But my Arcady, as you will see, is none the less tolerably broad and
eclectic in its limits. These various essays have been suggested to my
pen by rambles far and wide between its elastic confines. The little
tractate on _Mud_, for example, recalls to mind some pleasant weeks
among the Italian lakes and on the plain of Lombardy. _A Desert Fruit_
owes its origin to a morning at Luxor. _High Life_ had its key-note
struck by a fortnight in the Tyrol. _Tropical Education_ is a dim
reminiscence of old Jamaican experiences. Our _Eight-Legged Friends_
were observed at leisure on the window-panes of our own little nook at
Dorking. _A Hill-Top Stronghold_ was sketched _in situ_ at Florence by
a window that looked across the valley to Fiesole. Excursions into
books or into the remoter past have given occasion for the
archaeological essays relegated here to the end of the volume.

My thanks are due to Messrs. Longmans for permission to reprint from
their magazine _My Islands_, _A Hill-Top Stronghold_, _A Desert Fruit_,
_The Isle of Ruim_, _Eight-Legged Friends_, and _Tropical Education_. I
have also to acknowledge a similar courtesy on the part of Messrs.
Smith & Elder with regard to _Mud_, _The Bronze Axe_, _High Life_,
_Pretty Poll_, _The Greenwood Tree_, _On the Wings of the Wind_,
_Casters and Chesters_, and _Fish as Fathers_, all of which originally
appeared in the _Cornhill_. Messrs. Chatto & Windus have been equally
kind as regards the paper on _An English Shire_ contributed to the
_Gentleman's_. _A Persistent Nationality_ made its first bow in the
_North American Review_, and has still to be introduced to an English
audience.

G.A.

Hind Head, Surrey, _Oct._, 1892.

SCIENCE IN ARCADY.

MY ISLANDS.

About the middle of the Miocene period, as well as I can now remember
(for I made no note of the precise date at the moment), my islands
first appeared above the stormy sheet of the North-West Atlantic as a
little rising group of mountain tops, capping a broad boss of submarine
volcanoes. My attention was originally called to the new archipelago by
a brother investigator of my own aerial race, who pointed out to me on
the wing that at a spot some 900 miles to the west of the Portuguese
coast, just opposite the place where your mushroom city of Lisbon now
stands, the water of the ocean, as seen in a bird's-eye view from some
three thousand feet above, formed a distinct greenish patch such as
always betokens shoals or rising ground at the bottom. Flying out at
once to the point he indicated, and poising myself above it on my broad
pinions at a giddy altitude, I saw at a glance that my friend was quite
right. Land making was in progress. A volcanic upheaval was taking
place on the bed of the sea. A new island group was being forced right
up by lateral pressure or internal energies from a depth of at least
two thousand fathoms.

I had always had a great liking for the study of material plants and
animals, and I was so much interested in the occurrence of this novel
phenomenon--the growth and development of an oceanic island before my
very eyes--that I determined to devote the next few thousand centuries
or so of my aeonian existence to watching the course of its gradual
evolution.

If I trusted to unaided memory, however, for my dates and facts, I
might perhaps at this distance of time be uncertain whether the moment
was really what I have roughly given, within a geological age or two,
the period of the Mid-Miocene. But existing remains on one of the
islands constituting my group (now called in your new-fangled
terminology Santa Maria) help me to fix with comparative certainty the
precise epoch of their original upheaval. For these remains, still in
evidence on the spot, consist of a few small marine deposits of Upper
Miocene age; and I recollect distinctly that after the main group had
been for some time raised above the surface of the ocean, and after
sand and streams had formed a small sedimentary deposit containing
Upper Miocene fossils beneath the shoal water surrounding the main
group, a slight change of level occurred, during which this minor
island was pushed up with the Miocene deposits on its shoulders, as a
sort of natural memorandum to assist my random scientific
recollections. With that solitary exception, however, the entire group
remains essentially volcanic in its composition, exactly as it was when
I first saw its youthful craters and its red-hot ash-cones pushed
gradually up, century after century, from the deep blue waters of the
Mid-Miocene ocean.

All round my islands the Atlantic then, as now, had a depth, as I said
before, of two thousand fathoms; indeed, in some parts between the
group and Portugal the plummet of your human navigators finds no
bottom, I have often heard them say, till it reaches 2,500; and out of
this profound sea-bed the volcanic energies pushed up my islands as a
small submarine mountain range, whose topmost summits alone stood out
bit by bit above the level of the surrounding sea. One of them, the
most abrupt and cone-like, by name now Pico, rises to this day, a
magnificent sight, sheer seven thousand feet into the sky from the
placid sheet that girds it round on every side. You creatures of
to-day, approaching it in one of your clumsy new-fashioned fire-driven
canoes that you call steamers, must admire immensely its conical peak,
as it stands out silhouetted against the glowing horizon in the deep
red glare of a sub-tropical Atlantic sunset.

But when I, from my solitary aerial perch, saw my islands rise bare and
massive first from the water's edge, the earliest idea that occurred to
me as an investigator of nature was simply this: how will they ever get
clad with soil and herbage and living creatures? So naked and barren
were their black crags and rocks of volcanic slag, that I could hardly
conceive how they could ever come to resemble the other smiling oceanic
islands which I looked down upon in my flight from day to day over so
many wide and scattered oceans. I set myself to watch, accordingly,
whence they would derive the first seeds of life, and what changes
would take place under dint of time upon their desolate surface.

For a long epoch, while the mountains were still rising in their active
volcanic state, I saw but little evidence of a marked sort of the
growth of living creatures upon their loose piles of pumice. Gradually,
however, I observed that spores of lichens, blown towards them by the
wind, were beginning to sprout upon the more settled rocks, and to
discolour the surface in places with grey and yellow patches. Bit by
bit, as rain fell upon the new-born hills, it brought down from their
weathered summits sand and mud, which the torrents ground small and
deposited in little hollows in the valleys; and at last something like
earth was found at certain spots, on which seeds, if there had been
any, might doubtless have rooted and flourished exceedingly.

My primitive idea, as I watched my islands in this their almost
lifeless condition, was that the Gulf Stream and the trade winds from
America would bring the earliest higher plants and animals to our
shores. But in this I soon found I was quite mistaken. The distance to
be traversed was so great, and the current so slow, that the few seeds
or germs of American species cast up upon the shore from time to time
were mostly far too old and water-logged to show signs of life in such
ungenial conditions. It was from the nearer coasts of Europe, on the
contrary, that our earliest colonists seemed to come. Though the
prevalent winds set from the west, more violent storms reached us
occasionally from the eastward direction; and these, blowing from
Europe, which lay so much closer to our group, were far more likely to
bring with them by waves or wind some waifs and strays of the European
fauna and flora.

I well remember the first of these great storms that produced any
distinct impression on my islands. The plants that followed in its wake
were a few small ferns, whose light spores were more readily carried on
the breeze than any regular seeds of flowering plants. For a month or
two nothing very marked occurred in the way of change, but slowly the
spores rooted, and soon produced a small crop of ferns, which, finding
the ground unoccupied, spread when once fairly started with
extraordinary rapidity, till they covered all the suitable positions
throughout the islands.

For the most part, however, additions to the flora, and still more to
the fauna, were very gradually made; so much so that most of the
species now found in the group did not arrive there till after the end
of the Glacial epoch, and belong essentially to the modern European
assemblage of plants and animals. This was partly because the islands
themselves were surrounded by pack-ice during that chilly period, which
interrupted for a time the course of my experiment. It was interesting,
too, after the ice cleared away, to note what kinds could manage by
stray accidents to cross the ocean with a fair chance of sprouting or
hatching out on the new soil, and which were totally unable by original
constitution to survive the ordeal of immersion in the sea. For
instance, I looked anxiously at first for the arrival of some casual
acorn or some floating filbert, which might stock my islands with
waving greenery of oaks and hazel bushes. But I gradually discovered,
in the course of a few centuries, that these heavy nuts never floated
securely so far as the outskirts of my little archipelago; and that
consequently no chestnuts, apple trees, beeches, alders, larches, or
pines ever came to diversify my island valleys. The seeds that did
really reach us from time to time belonged rather to one or other of
four special classes. Either they were very small and light, like the
spores of ferns, fungi, and club-mosses; or they were winged and
feathery, like dandelion and thistle-down; or they were the stones of
fruits that are eaten by birds, like rose-hips and hawthorn; or they
were chaffy grains, enclosed in papery scales, like grasses and sedges,
of a kind well adapted to be readily borne on the surface of the water.
In all these ways new plants did really get wafted by slow degrees to
the islands; and if they were of kinds adapted to the climate they grew
and flourished, living down the first growth of ferns and flowerless
herbs in the rich valleys.

The time which it took to people my archipelago with these various
plants was, of course, when judged by your human standards, immensely
long, as often the group received only a single new addition in the
lapse of two or three centuries. But I noticed one very curious result
of this haphazard and lengthy mode of stocking the country: some of the
plants which arrived the earliest, having the coast all clear to
themselves, free from the fierce competition to which they had always
been exposed on the mainland of Europe, began to sport a great deal in
various directions, and being acted upon here by new conditions, soon
assumed under stress of natural selection totally distinct specific
forms. (You see, I have quite mastered your best modern scientific
vocabulary.) For instance, there were at first no insects of any sort
on the islands; and so those plants which in Europe depended for their
fertilisation upon bees or butterflies had here either to adapt
themselves somehow to the wind as a carrier of their pollen or else to
die out for want of crossing. Again, the number of enemies being
reduced to a minimum, these early plants tended to lose various
defences or protections they had acquired on the mainland against slugs
or ants, and so to become different in a corresponding degree from
their European ancestors. The consequence was that by the time you men
first discovered the archipelago no fewer than forty kinds of plants
had so far diverged from the parent forms in Europe or elsewhere that
your savants considered them at once as distinct species, and set them
down at first as indigenous creations. It amused me immensely.

For out of these forty plants thirty-four were to my certain knowledge
of European origin. I had seen their seeds brought over by the wind or
waves, and I had watched them gradually altering under stress of the
new conditions into fresh varieties, which in process of time became
distinct species. Two of the oldest were flowers of the dandelion and
daisy group, provided with feathery seeds which enable them to fly far
before the carrying breeze; and these two underwent such profound
modifications in their insular home that the systematic botanists who
at last examined them insisted upon putting each into a new genus, all
by itself, invented for the special purpose of their reception. One
almost equally ancient inhabitant, a sort of harebell, also became in
process of time extremely unlike any other harebell I had ever seen in
any part of my airy wanderings. But the remaining thirty new species or
so evolved in the islands by the special circumstances of the group had
varied so comparatively little from their primitive European ancestors,
that they hardly deserved to be called anything more than very distinct
and divergent varieties.

Some five or six plants, however, I noted arrive in my archipelago, not
from Europe, but from the Canaries or Madeira, whose distant blue peaks
lay dim on the horizon far to the south-west of us, as I poised in
mid-air high above the topmost pinnacle of my wild craggy Pico. These
kinds, belonging to a much warmer region, soon, as I noticed, underwent
considerable modification in our cooler climate, and were all of them
adjudged distinct species by the learned gentlemen who finally reported
upon my island realm to British science.

As far as I can recollect, then, the total number of flowering plants I
noted in the islands before the arrival of man was about 200; and of
these, as I said before, only forty had so far altered in type as to be
considered at present peculiar to the archipelago. The remainder were
either comparatively recent arrivals or else had found the conditions
of their new home so like those of the old one from which they
migrated, that comparatively little change took place in their forms or
habits. Of course, just in proportion as the islands got stocked I
noticed that the changes were less and less marked; for each new plant,
insect, or bird that established itself successfully tended to make the
balance of nature more similar to the one that obtained in the mainland
opposite, and so decreased the chances of novelty of variation.

Hence, it struck me that the oldest arrivals were the ones which
altered most in adaptation to the circumstances, while the newest,
finding themselves in comparatively familiar surroundings, had less
occasion to be selected for strange and curious freaks or sports of
form or colour.

The peopling of the islands with birds and animals, however, was to me
even a more interesting and engrossing study in natural evolution than
its peopling by plants, shrubs, and trees. I may as well begin,
therefore, by telling you at once that no furry or hairy quadruped of
any sort--no mammal, as I understand your men of science call them--was
ever stranded alive upon the shores of my islands. For twenty or thirty
centuries indeed, I waited patiently, examining every piece of
driftwood cast up upon our beaches, in the faint hope that perhaps some
tiny mouse or shrew or water-vole might lurk half drowned in some
cranny or crevice of the bark or trunk. But it was all in vain. I ought
to have known beforehand that terrestrial animals of the higher types
never by any chance reach an oceanic island in any part of this planet.
The only three specimens of mammals I ever saw tossed up on the beach
were two drowned mice and an unhappy squirrel, all as dead as
doornails, and horribly mauled by the sea and the breakers. Nor did we
ever get a snake, a lizard, a frog, or a fresh-water fish, whose eggs I
at first fondly supposed might occasionally be transported to us on
bits of floating trees or matted turf, torn by floods from those
prehistoric Lusitanian or African forests. No such luck was ours. Not a
single terrestrial vertebrate of any sort appeared upon our shores
before the advent of man with his domestic animals, who played havoc at
once with my interesting experiment.

It was quite otherwise with the unobtrusive small deer of life--the
snails, and beetles, and flies, and earthworms--and especially with the
winged things: birds, bats, and butterflies. In the very earliest days
of my islands' existence, indeed, a few stray feathered fowls of the
air were driven ashore here by violent storms, at a time when
vegetation had not yet begun to clothe the naked pumice and volcanic
rock; but these, of course, perished for want of food, as did also a
few later arrivals, who came under stress of weather at the period when
only ferns, lichens, and mosses had as yet obtained a foothold on the
young archipelago. Sea-birds, of course, soon found out our rocks; but
as they live off fish only, they contributed little more than rich beds
of guano to the permanent colonising of the islands. As well as I can
remember, the land-snails were the earliest truly terrestrial casuals
that managed to pick up a stray livelihood in these first colonial days
of the archipelago. They came oftenest in the egg, sometimes clinging
to water-logged leaves cast up by storms, sometimes hidden in the bark
of floating driftwood, and sometimes swimming free on the open ocean.
In one case, as I recall to myself well, a swallow, driven off from the
Portuguese coast, a little before the Glacial period had begun to
whiten the distant mountains of central and northern Europe, fell
exhausted at last upon the shore of Terceira. There were no insects
then for the poor bird to feed upon, so it died of starvation and
weariness before the day was out; but a little earth that clung in a
pellet to one of its feet contained the egg of a land-shell, while the
prickly seed of a common Spanish plant was entangled among the winged
feathers by its hooked awns. The egg hatched out, and became the parent
of a large brood of minute snails, which, outliving the cold spell of
the Ice Age, had developed into a very distinct type in the long period
that intervened before the advent of man in the islands; while the seed
sprang up on the natural manure heap afforded by the swallow's decaying
body, and clinging to the valleys during the Glacial Age on the
hill-tops, gave birth in due season to one of the most markedly
indigenous of our Terceira plants.

Occasionally, too, very minute land-snails would arrive alive on the
island after their long sea-voyage on bits of broken forest-trees--a
circumstance which I would perhaps hesitate to mention in mere human
society were it not that I have been credibly informed your own great
naturalist, Darwin, tried the experiment himself with one of the
biggest European land-molluscs, the great edible Roman snail, and found
that it still lived on in vigorous style after immersion in sea-water
for twenty days. Now, I myself observed that several of these bits of
broken trees, torn down by floods in heavy storm time from the banks of
Spanish or Portuguese rivers, reached my island in eight or ten days
after leaving the mainland, and sometimes contained eggs of small
land-snails. But as very long periods often passed without a single new
species being introduced into the group, any kind that once managed to
establish itself on any of the islands usually remained for ages
undisturbed by new arrivals, and so had plenty of opportunity to adapt
itself perfectly by natural selection to the new conditions. The
consequence was, that out of some seventy land-snails now known in the
islands, thirty-two had assumed distinct specific features before the
advent of man, while thirty-seven (many of which, I think, I never
noticed till the introduction of cultivated plants) are common to my
group with Europe or with the other Atlantic islands. Most of these, I
believe, came in with man and his disconcerting agriculture.

As to the pond and river snails, so far as I could observe, they mostly
reached us later, being conveyed in the egg on the feet of stray waders
or water-birds, which gradually peopled the island after the Glacial
epoch.

Birds and all other flying creatures are now very abundant in all the
islands; but I could tell you some curious and interesting facts, too,
as to the mode of their arrival and the vicissitudes of their
settlement. For example, during the age of the Forest Beds in Europe, a
stray bullfinch was driven out to sea by a violent storm, and perched
at last on a bush at Fayal. I wondered at first whether he would effect
a settlement. But at that time no seeds or fruits fit for bullfinches
to eat existed on the islands. Still, as it turned out, this particular
bullfinch happened to have in his crop several undigested seeds of
European plants exactly suited to the bullfinch taste; so when he died
on the spot, these seeds, germinating abundantly, gave rise to a whole
valleyful of appropriate plants for bullfinches to feed upon. Now,
however, there was no bullfinch to eat them. For a long time, indeed,
no other bullfinches arrived at my archipelago. Once, to be sure, a few
hundred years later, a single cock bird did reach the island alone,
much exhausted with his journey, and managed to pick up a living for
himself off the seeds introduced by his unhappy predecessor. But as he
had no mate, he died at last, as your lawyers would say, without issue.

It was a couple of hundred years or so more before I saw a third
bullfinch--which didn't surprise me, for bullfinches are very woodland
birds, and non-migratory into the bargain--so that they didn't often
get blown seaward over the broad Atlantic. At the end of that time,
however, I observed one morning a pair of finches, after a heavy storm,
drying their poor battered wings upon a shrub in one of the islands.
From this solitary pair a new race sprang up, which developed after a
time, as I imagined they must, into a distinct species. These local
bullfinches now form the only birds peculiar to the islands; and the
reason is one well divined by one of your own great naturalists (to
whom I mean before I end to make the _amende honorable_). In almost all
other cases the birds kept getting reinforced from time to time by
others of their kind blown out to sea accidentally--for only such
species were likely to arrive there--and this kept up the purity of the
original race, by ensuring a cross every now and again with the
European community. But the bullfinches, being the merest casuals,
never again to my knowledge were reinforced from the mainland, and so
they have produced at last a special island type, exactly adapted to
the peculiarities of their new habitat.

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