Scientific Essays and Lectures - Charles Kingsley
Scientific Lectures and Essays
Contents: {0}
On Bio-Geology
The Study of Natural History
Superstition
Science
Thoughts in a Gravel-Pit
How to Study Natural History
The Natural Theology of the Future
ON BIO-GEOLOGY {1}
I am not sure that the subject of my address is rightly chosen. I
am not sure that I ought not to have postponed a question of mere
natural history, to speak to you as scientific men, on the questions
of life and death, which have been forced upon us by the awful
warning of an illustrious personage's illness; of preventible
disease, its frightful prevalency; of the 200,000 persons who are
said to have died of fever alone since the Prince Consort's death,
ten years ago; of the remedies; of drainage; of sewage disinfection
and utilisation; and of the assistance which you, as a body of
scientific men, can give to any effort towards saving the lives and
health of our fellow-citizens from those unseen poisons which lurk
like wild beasts couched in the jungle, ready to spring at any
moment on the unsuspecting, the innocent, the helpless. Of all this
I longed to speak; but I thought it best only to hint at it, and
leave the question to your common sense and your humanity; taking
for granted that your minds, like the minds of all right-minded
Englishmen, have been of late painfully awakened to its importance.
It seemed to me almost an impertinence to say more in a city of
whose local circumstances I know little or nothing. As an old
sanitary reformer, practical, as well as theoretical, I am but too
well aware of the difficulties which beset any complete scheme of
drainage, especially in an ancient city like this; where men are
paying the penalty of their predecessors' ignorance; and dwelling,
whether they choose or not, over fifteen centuries of accumulated
dirt.
And, therefore, taking for granted that there is energy and
intellect enough in Winchester to conquer these difficulties in due
time, I go on to ask you to consider, for a time, a subject which is
growing more and more important and interesting, a subject the study
of which will do much towards raising the field naturalist from a
mere collector of specimens--as he was twenty years ago--to a
philosopher elucidating some of the grandest problems. I mean the
infant science of Bio-geology--the science which treats of the
distribution of plants and animals over the globe, and the cause of
that distribution.
I doubt not that there are many here who know far more about the
subject than I; who are far better read than I am in the works of
Forbes, Darwin, Wallace, Hooker, Moritz Wagner, and the other
illustrious men who have written on it. But I may, perhaps, give a
few hints which will be of use to the younger members of this
Society, and will point out to them how to get a new relish for the
pursuit of field science.
Bio-geology, then, begins with asking every plant or animal you
meet, large or small, not merely--What is your name? That is the
collector and classifier's duty; and a most necessary duty it is,
and one to be performed with the most conscientious patience and
accuracy, so that a sound foundation may be built for future
speculations. But young naturalists should act not merely as
Nature's registrars and census-takers, but as her policemen and
gamekeepers; and ask everything they meet--How did you get there?
By what road did you come? What was your last place of abode? And
now you are here, how do you get your living? Are you and your
children thriving, like decent people who can take care of
themselves, or growing pauperised and degraded, and dying out? Not
that we have a fear of your becoming a dangerous class. Madame
Nature allows no dangerous classes, in the modern sense. She has,
doubtless for some wise reason, no mercy for the weak. She rewards
each organism according to its works; and if anything grows too weak
or stupid to take care of itself, she gives it its due deserts by
letting it die and disappear. So, you plant or you animal, are you
among the strong, the successful, the multiplying, the colonising?
Or are you among the weak, the failing, the dwindling, the doomed?
These questions may seem somewhat rude: but you may comfort
yourself by the thought that plants and animals, though they deserve
all kindness, all admiration, deserve no courtesy--at least in this
respect. For they are, one and all, wherever you find them,
vagrants and landlopers, intruders and conquerors, who have got
where they happen to be simply by the law of the strongest--
generally not without a little robbery and murder. They have no
right save that of possession; the same by which the puffin turns
out the old rabbits, eats the young ones, and then lays her eggs in
the rabbit-burrow--simply because she can.
Now, you will see at once that such a course of questioning will
call out a great many curious and interesting answers, if you can
only get the things to tell you their story; as you always may if
you will cross-examine them long enough; and will lead you into many
subjects beside mere botany or entomology. So various, indeed, are
the subjects which you will thus start, that I can only hint at them
now in the most cursory fashion.
At the outset you will soon find yourself involved in chemical and
meteorological questions; as, for instance, when you ask--How is it
that I find one flora on the sea-shore, another on the sandstone,
another on the chalk, and another on the peat-making gravelly
strata? The usual answer would be, I presume--if we could work it
out by twenty years' experiment, such as Mr. Lawes, of Rothampsted,
has been making on the growth of grasses and leguminous plants in
different soils and under different manures--the usual answer, I
say, would be--Because we plants want such and such mineral
constituents in our woody fibre; again, because we want a certain
amount of moisture at a certain period of the year: or, perhaps,
simply because the mechanical arrangement of the particles of a
certain soil happens to suit the shape of our roots and of their
stomata. Sometimes you will get an answer quickly enough; sometimes
not. If you ask, for instance, Asplenium viride how it contrives to
grow plentifully in the Craven of Yorkshire down to 600 or 800 feet
above the sea, while in Snowdon it dislikes growing lower than 2000
feet, and is not plentiful even there?--it will reply--Because in
the Craven I can get as much carbonic acid as I want from the
decomposing limestone; while on the Snowdon Silurian I get very
little; and I have to make it up by clinging to the mountain tops,
for the sake of the greater rainfall. But if you ask Polypodium
calcareum--How is it you choose only to grow on limestone, while
Polypodium Dryopteris, of which, I suspect, you are only a variety,
is ready to grow anywhere?--Polypodium calcareum will refuse, as
yet, to answer a word.
Again--I can only give you the merest string of hints--you will find
in your questionings that many plants and animals have no reason at
all to show why they should be in one place and not in another, save
the very sound reason for the latter which was suggested to me once
by a great naturalist. I was asking--Why don't I find such and such
a species in my parish, while it is plentiful a few miles off in
exactly the same soil?--and he answered--For the same reason that
you are not in America. Because you have not got there. Which
answer threw to me a flood of light on this whole science. Things
are often where they are, simply because they happen to have got
there, and not elsewhere. But they must have got there by some
means, and those means I want young naturalists to discover; at
least, to guess at.
A species, for instance--and I suspect it is a common case with
insects--may abound in a single spot, simply because, long years
ago, a single brood of eggs happened to hatch at a time when eggs of
other species, who would have competed against them for food, did
not hatch; and they may remain confined to that spot, though there
is plenty of food for them outside it, simply because they do not
increase fast enough to require to spread out in search of more
food. Thus I should explain a case which I heard of lately of
Anthocera trifolii, abundant for years in one corner of a certain
field, and only there; while there was just as much trefoil all
round for its larvae as there was in the selected spot. I can, I
say, only give hints: but they will suffice, I hope, to show the
path of thought into which I want young naturalists to turn their
minds.
Or, again, you will have to inquire whether the species has not been
prevented from spreading by some natural barrier. Mr. Wallace, whom
you all of course know, has shown in his "Malay Archipelago" that a
strait of deep sea can act as such a barrier between species.
Moritz Wagner has shown that, in the case of insects, a moderately-
broad river may divide two closely-allied species of beetles, or a
very narrow snow-range, two closely-allied species of moths.
Again, another cause, and a most common one, is: that the plants
cannot spread because they find the ground beyond them already
occupied by other plants, who will not tolerate a fresh mouth,
having only just enough to feed themselves. Take the case of
Saxifraga hypnoides and S. umbrosa, "London pride." They are two
especially strong species. They show that, S. hypnoides especially,
by their power of sporting, of diverging into varieties; they show
it equally by their power of thriving anywhere, if they can only get
there. They will grow both in my sandy garden, under a rainfall of
only 23 inches, more luxuriantly than in their native mountains
under a rainfall of 50 or 60 inches. Then how is it that S.
hypnoides cannot get down off the mountains; and that S. umbrosa,
though in Kerry it has got off the mountains and down to the sea-
level, exterminating, I suspect, many species in its progress, yet
cannot get across County Cork? The only answer is, I believe, that
both species are continually trying to go ahead; but that the other
plants already in front of them are too strong for them, and
massacre their infants as soon as born.
And this brings us to another curious question: the sudden and
abundant appearance of plants, like the foxglove and Epilobium
angustifolium, in spots where they have never been seen before. Are
there seeds, as some think, dormant in the ground; or are the seeds
which have germinated, fresh ones wafted thither by wind or
otherwise, and only able to germinate in that one spot because there
the soil is clear? General Monro, now famous for his unequalled
memoir on the bamboos, holds to the latter theory. He pointed out
to me that the Epilobium seeds, being feathered could travel with
the wind; that the plant always made its appearance first on new
banks, landslips, clearings, where it had nothing to compete
against; and that the foxglove did the same. True, and most
painfully true, in the case of thistles and groundsels: but
foxglove seeds, though minute, would hardly be carried by the wind
any more than those of the white clover, which comes up so
abundantly in drained fens. Adhuc sub judice lis est, and I wish
some young naturalists would work carefully at the solution; by
experiment, which is the most sure way to find out anything.
But in researches in this direction they will find puzzles enough.
I will give them one which I shall be most thankful to hear they
have solved within the next seven years--How is it that we find
certain plants, namely, the thrift and the scurvy grass, abundant on
the sea-shore and common on certain mountain-tops, but nowhere
between the two? Answer me that. For I have looked at the fact for
years--before, behind, sideways, upside down, and inside out--and I
cannot understand it.
But all these questions, and especially, I suspect, that last one,
ought to lead the young student up to the great and complex
question--How were these islands re-peopled with plants and animals,
after the long and wholesale catastrophe of the glacial epoch?
I presume you all know, and will agree, that the whole of these
islands, north of the Thames, save certain ice-clad mountain-tops,
were buried for long ages under an icy sea. From whence did
vegetable and animal life crawl back to the land, as it rose again;
and cover its mantle of glacial drift with fresh life and verdure?
Now let me give you a few prolegomena on this matter. You must
study the plants of course, species by species. Take Watson's
"Cybele Britannica" and Moore's "Cybele Hibernica;" and let--as Mr.
Matthew Arnold would say--"your thought play freely about them."
Look carefully, too, in the case of each species, at the note on its
distribution, which you will find appended in Bentham's "Handbook,"
and in Hooker's "Student's Flora." Get all the help you can, if you
wish to work the subject out, from foreign botanists, both European
and American; and I think that, on the whole, you will come to some
such theory as this for a general starling platform. We do not owe
our flora--I must keep to the flora just now--to so many different
regions, or types, as Mr. Watson conceives, but to three, namely, an
European or Germanic flora, from the south-east; an Atlantic flora,
from the south-east; a Northern flora, from the north. These three
invaded us after the glacial epoch; and our general flora is their
result.
But this will cause you much trouble. Before you go a step farther
you will have to eliminate from all your calculations most of the
plants which Watson calls glareal, i.e. found in cultivated ground
about habitations. And what their limit may be I think we never
shall know. But of this we may be sure; that just as invading
armies always bring with them, in forage or otherwise, some plants
from their own country--just as the Cossacks, in 1815, brought more
than one Russian plant through Germany into France--just as you have
already a crop of North German plants upon the battle-fields of
France--thus do conquering races bring new plants. The Romans,
during their 300 or 400 years of occupation and civilisation, must
have brought more species, I believe, than I dare mention. I
suspect them of having brought, not merely the common hedge elm of
the south, not merely the three species of nettle, but all our red
poppies, and a great number of the weeds which are common in our
cornfields; and when we add to them the plants which may have been
brought by returning crusaders and pilgrims; by monks from every
part of Europe, by Flemings or other dealers in foreign wool--we
have to cut a huge cantle out of our indigenous flora: only, having
no records, we hardly know where and what to cut out; and can only,
we elder ones, recommend the subject to the notice of the younger
botanists, that they may work it out after our work is done.
Of course these plants introduced by man, if they are cut out, must
be cut out of only one of the floras, namely, the European; for
they, probably, came from the south-east, by whatever means they
came.
That European flora invaded us, I presume, immediately after the
glacial epoch, at a time when France and England were united, and
the German Ocean a mere network of rivers, which emptied into the
deep sea between Scotland and Scandinavia. And here I must add,
that endless questions of interest will arise to those who will
study, not merely the invasion of that truly European flora, but the
invasion of reptiles, insects, and birds, especially birds of
passage, which must have followed it as soon as the land was
sufficiently covered with vegetation to support life. Whole volumes
remain to be written on this subject. I trust that some of your
younger members may live to write one of them. The way to begin
will be; to compare the flora and fauna of this part of England very
carefully with that of the southern and eastern counties; and then
to compare them again with the fauna and flora of France, Belgium,
and Holland.
As for the Atlantic flora, you will have to decide for yourselves
whether you accept or not the theory of a sunken Atlantic continent.
I confess that all objections to that theory, however astounding it
may seem, are outweighed in my mind by a host of facts which I can
explain by no other theory. But you must judge for yourselves; and
to do so you must study carefully the distribution of heaths both in
Europe and at the Cape, and their non-appearance beyond the Ural
Mountains, and in America, save in Labrador, where the common ling,
an older and less specialised form, exists. You must consider, too,
the plants common to the Azores, Portugal, the West of England,
Ireland, and the Western Hebrides. In so doing young naturalists
will at least find proofs of a change in the distribution of land
and water, which will utterly astound them when they face it for the
first time.
As for the Northern flora, the question whence it came is puzzling
enough. It seems difficult to conceive how any plants could have
survived when Scotland was an archipelago in the same ice-covered
condition as Greenland is now; and we have no proof that there
existed after the glacial epoch any northern continent from which
the plants and animals could have come back to us. The species of
plants and animals common to Britain, Scandinavia, and North
America, must have spread in pre-glacial times when a continent
joining them did exist.
But some light has been thrown on this question by an article, as
charming as it is able, on "The Physics of the Arctic Ice," by Dr.
Brown of Campster. You will find it in the "Quarterly Journal of
the Geological Society" for February, 1870. He shows there that
even in Greenland peaks and crags are left free enough from ice to
support a vegetation of between three hundred or four hundred
species of flowering plants; and, therefore, he well says, we must
be careful to avoid concluding that the plant and animal life on the
dreary shores or mountain-tops of the old glacial Scotland was poor.
The same would hold good of our mountains; and, if so, we may look
with respect, even awe, on the Alpine plants of Wales, Scotland, and
the Lake mountains, as organisms, stunted it may be, and even
degraded by their long battle with the elements, but venerable from
their age, historic from their endurance. Relics of an older
temperate world, they have lived through thousands of centuries of
frost and fog, to sun themselves in a temperate climate once more.
I can never pick one of them without a tinge of shame; and to
exterminate one of them is to destroy, for the mere pleasure of
collecting, the last of a family which God has taken the trouble to
preserve for thousands of centuries.
I trust that these hints--for I can call them nothing more--will at
least awaken any young naturalist who has hitherto only collected
natural objects, to study the really important and interesting
question--How did these things get here?
Now hence arise questions which may puzzle the mind of a Hampshire
naturalist. You have in this neighbourhood, as you well know, two,
or rather three, soils, each carrying its peculiar vegetation.
First, you have the clay lying on the chalk, and carrying vast
woodlands, seemingly primeval. Next, you have the chalk, with its
peculiar, delicate, and often fragrant crop of lime-loving plants;
and next, you have the poor sands and clays of the New Forest basin,
saturated with iron, and therefore carrying a moorland or peat-
loving vegetation, in many respects quite different from the others.
And this moorland soil, and this vegetation, with a few singular
exceptions, repeats itself, as I daresay you know, in the north of
the county, in the Bagshot basin, as it is called--the moors of
Aldershot, Hartford Bridge, and Windsor Forest.
Now what a variety of interesting questions are opened up by these
simple facts. How did these three floras get each to its present
place? Where did each come from? How did it get past or through
the other, till each set of plants, after long internecine
competition, settled itself down in the sheet of land most congenial
to it? And when did each come hither? Which is the oldest? Will
any one tell me whether the healthy floras of the moors, or the
thymy flora of the chalk downs, were the earlier inhabitants of
these isles? To these questions I cannot get any answer; and they
cannot be answered without, first--a very careful study of the range
of each species of plant on the continent of Europe; and next,
without careful study of those stupendous changes in the shape of
this island which have taken place at a very late geological epoch.
The composition of the flora of our moorlands is as yet to me an
utter puzzle. We have Lycopodiums--three species--enormously
ancient forms which have survived the age of ice: but did they
crawl downward hither from the northern mountains or upward hither
from the Pyrenees? We have the beautiful bog asphodel again--an
enormously ancient form; for it is, strange to say, common to North
America and to Northern Europe, but does not enter Asia--almost an
unique instance. It must, surely, have come from the north; and
points--as do many species of plants and animals--to the time when
North Europe and North America were joined. We have, sparingly, in
North Hampshire, though, strangely, not on the Bagshot moors, the
Common or Northern Butterwort (Pinguicula vulgaris); and also, in
the south, the New Forest part of the county, the delicate little
Pinguicula lusitanica, the only species now found in Devon and
Cornwall, marking the New Forest as the extreme eastern limit of the
Atlantic flora. We have again the heaths, which, as I have just
said, are found neither in America nor in Asia, and must, I believe,
have come from some south-western land long since submerged beneath
the sea. But more, we have in the New Forest two plants which are
members of the South Europe, or properly, the Atlantic flora; which
must have come from the south and south-east; and which are found in
no other spots in these islands. I mean the lovely Gladiolus, which
grows abundantly under the ferns near Lyndhurst, certainly wild, but
it does not approach England elsewhere nearer than the Loire and the
Rhine; and next, that delicate orchid, the Spiranthes aestivalis,
which is known only in a bog near Lyndhurst and in the Channel
Islands, while on the Continent it extends from Southern Europe all
through France. Now, what do these two plants mark? They give us a
point in botany, though not in time, to determine when the south of
England was parted from the opposite shores of France; and whenever
that was, it was just after the Gladiolus and Spiranthes got hither.
Two little colonies of these lovely flowers arrived just before
their retreat was cut off. They found the country already occupied
with other plants; and, not being reinforced by fresh colonists from
the south, have not been able to spread farther north than
Lyndhurst. Thus, in the New Forest, and, I may say in the Bagshot
moors, you find plants which you do not expect, and do not find
plants which you do expect; and you are, or ought to be, puzzled,
and I hope also interested, and stirred up to find out more.
I spoke just now of the time when England was joined to France, as
bearing on Hampshire botany. It bears no less on Hampshire zoology.
In insects, for instance, the presence of the purple emperor and the
white admiral in our Hampshire woods, as well as the abundance of
the great stag-beetle, point to a time when the two countries were
joined, at least as far west as Hampshire; while the absence of
these insects farther to the westward shows that the countries, if
ever joined, were already parted; and that those insects have not
yet had time to spread westward. The presence of these two
butterflies, and partly of the stag-beetle, along the south-east
coast of England as far as the primeval forests of South
Lincolnshire, points, as do a hundred other facts, to a time when
the Straits of Dover either did not exist, or were the bed of a
river running from the west; and when, as I told you just now, all
the rivers which now run into the German Ocean, from the Humber on
the west to the Elbe on the east, discharged themselves into the sea
between Scotland and Norway, after wandering through a vast lowland,
covered with countless herds of mammoth, rhinoceros, gigantic ox,
and other mammals now extinct; while the birds, as far as we know,
the insects, the fresh-water fish, and even, as my friend Mr. Brady
has proved, the Entomostraca of the rivers, were the same in what is
now Holland as in what is now our Eastern counties. I could dwell
long on this matter. I could talk long about how certain species of
Lepidoptera--moths and butterflies--like Papilio Machaon and P.
Podalirius, swarm through France, reach up to the British Channel,
and have not crossed it, with the exception of one colony of Machaon
in the Cambridgeshire fens. I could talk long about a similar
phenomenon in the case of our migratory and singing birds; how many
exquisite species--notably those two glorious songsters, the Orphean
Warbler and Hippolais, which delight our ears everywhere on the
other side of the Channel--follow our nightingales, blackcaps, and
warblers northward every spring almost to the Straits of Dover, but
dare not cross, simply because they have been, as it were, created
since the gulf was opened, and have never learnt from their parents
how to fly over it.