We have already gathered much concerning Darwin's mental and moral fibre
in our survey of his works. Let us make some further acquaintance with
his personality as known to his friends. Outwardly he appeared a man of
powerful physique, standing six feet high, with prominent forehead and
over-arching brow, and keen, deep-set eyes in which resolute strength
and piercing insight were indicated. Apart from his persistent
infirmity, he was actively disposed, as indeed is evident from the
laborious journeys he undertook during his travels. Field sports,
including hunting, were among the recreations of his more active years.
But through all his work or recreation the imperious conditions
necessitated by his infirmity of stomach had to be considered, and
nothing but the most rigorous care could possibly have enabled him to
achieve what he did. On many days he could not work at all, and on many
others two or three hours were his limit. And what but his own system,
his own orderliness and perseverance could have accomplished his task?
In preparing his books he had a special set of shelves for each,
standing on or near his writing-table, one shelf for each chapter. The
maxim, "Early to bed, and early to rise," was his essentially, and
regularity kept all balanced. Rising at six, he took a cold plunge bath,
breakfasted simply, and took a first walk, beginning work often at
eight. "Later in the day," I quote from Mr. Woodall's pleasant pages,
"he generally walked again, often in his own grounds, but sometimes
further afield, and then generally by quiet footpaths rather than
frequented roads. The walks at one time were varied by rides along the
lanes on a favourite black cob, but some years before his death his
four-footed friend fell, and died by the roadside, and from that day the
habit of riding was given up. Part of the evening was devoted to his
family and his friends, who delighted to gather round him to enjoy the
charm of his bright intelligence, and his unrivalled stores of
knowledge. To Down, occasionally, came distinguished men from many
lands; and there in later years would sometimes be found the younger
generation of scientific students, looking up to the great naturalist
with the reverence of disciples, who had experienced his singular
modesty, his patient readiness to listen to all opinions, and the
winning grace with which he informed their ignorance and corrected their
mistakes. In the midst of all the delights of home and the demands of
study, Darwin kept an open mind for public affairs. He united the
earnest politician with the patient student: a rare combination, which
supplies another proof of his largeness of heart and sympathy with his
fellow men. In the village of Down he was liked by everybody, old and
young, and in his own household the same servants lived year after year
under his roof. One of them, Margaret Evans, who assisted in nursing
him in his last illness, had come to Down nearly forty years before,
from Shrewsbury, where her uncle and aunt were in Dr. Darwin's service."
At Down the family in time numbered nine children, two, however, not
surviving childhood; one died in 1842, another in 1858. His five sons
have already attained distinction or positions of influence. The eldest,
William Erasmus, became a banker in Southampton; the second, George, was
second Wrangler and Smith's Prizeman at Cambridge in 1868, became a
Fellow of Trinity, and is now Plumian Professor of Astronomy at his
university, having early gained the Fellowship of the Royal Society for
his original papers bearing on the evolution of the universe and the
solar system, and many other subjects of high mathematical and
philosophical interest. His third son, Francis, gained first-class
honours in the Cambridge Natural Science Tripos in 1870, and is likewise
a Fellow of the Royal Society, in recognition of his original botanical
investigations. The fourth, Leonard, an officer in the Royal Engineers,
has done valuable astronomical work. The fifth, Horace, has devoted
himself to mechanical science, and has largely aided in developing the
Cambridge Scientific Instrument Company.
The great thinker, fulfilling his duties as head of a family with
singular success, charged with the burden of new thoughts and
observations, slowly perfecting his life work, had neither time nor
inclination for controversy. He set himself to publish facts, which by
their accumulation tended to clench his arguments. Soon after the
"Origin of Species" he had in course of publication several important
botanical papers, on the two forms of flower in the Primrose genus
(1862), and in the genus Linum (flax), 1863, on the forms of
Loosestrife, 1864, all published in the Linnean Society's Journal.
In 1862 he brought out his first botanical book, the "Fertilisation of
Orchids," more fully entitled, "On the various Contrivances by which
Orchids are Fertilised by Insects." These most singular flowers had long
attracted great attention owing to their peculiar shapes and often their
great beauty, while their marked deviation from typical forms of flowers
perplexed botanists extremely. The celebrated Robert Brown, in a
well-known paper in the Linnean Society's Transactions, 1833, expressed
the belief that insects are necessary for the fructification of most
orchids; and as far back as 1793, Christian Sprengel (in "The Newly
Discovered Secret of Nature") gave an excellent account of the action of
the several parts in the genus Orchis, having discovered that insects
were necessary to remove the pollen masses. But the _rationale_ of the
process was not fully known until Darwin revealed it, and illuminated it
by the light of natural selection. He had, in the "Origin of Species,"
given reasons for the belief that it is an almost universal law of
nature that the higher organic beings require an occasional cross with
another individual. He here emphasised that doctrine by a series of
proofs from a peculiar and otherwise inexplicable order of plants, and
showed that the arrangements by which orchids are fertilised have for
their main object the fertilisation of the flowers with pollen brought
by insects from a distinct plant.
In the group to which our common orchids belong, remarkable adaptations
for securing that the pollen masses brought from another flower solely
through the visits of insects shall reach their precise destination,
were brought to light. "A poet," says Darwin, "might imagine that whilst
the pollinia were borne through the air from flower to flower, adhering
to an insect's body, they voluntarily and eagerly placed themselves in
that exact position in which alone they could hope to gain their wish
and perpetuate their race." As he had examined all the British genera,
Darwin's conclusions were indubitable. He had patiently watched for
hours on the grass to notice insects' visits, had counted the fertilised
flowers on many spikes, the fertilised spikes on many plants, had
dissected and redissected the flowers till he saw how the fertilisation
must absolutely be effected; and utilising the enthusiasm of orchid
growers, had excited them to do the same, till his storehouse of facts
was full.
On examining the exotic forms of orchids, which are so conspicuous in
our conservatories, still more striking facts presented themselves. In
the great group of the Vandeæ, relative position of parts, friction,
viscidity, elastic and hygrometric movements were all found to be nicely
related to one end--the aid of insects in fertilisation. Without their
aid not a plant in the various species of twenty-nine genera which
Darwin examined would set a seed. In the majority of cases insects
withdraw the pollen masses only when retreating from the flower, and,
continuing their flower visits, effect a union between two flowers,
generally on distinct plants. In many cases the pollen masses slowly
change their position while adhering to the insects, and so assume a
proper direction for striking the stigma of another flower, and the
insects during this interval will almost certainly have flown from one
plant to another.
The family to which Catasetum belongs furnished the most remarkable
examples. This plant possesses a special sensitiveness in certain parts,
and when definite points of the flower are touched by an insect the
pollen masses are shot forth like an arrow, the point being blunt and
adhesive. The insect, disturbed by so sharp a blow, or having eaten its
fill, flies sooner or later to a female plant, and whilst standing in
the same position as before, the pollen-bearing end of the arrow is
inserted into the stigmatic cavity, and a mass of pollen is left on its
viscid surface. The strange structures of Cypripedium, or the Lady's
Slipper, were then analysed, and the mode of fertilisation by small bees
was discovered. The whole structure of orchids, as modified to secure
insects' visits and cross fertilisation, was now expounded, and the
benefits shown by cases where insects' visits were prevented, and no
seed was set. The number of seeds in a capsule was reckoned, and thence
it was found that the progeny of a single plant of the common orchis
would suffice to cover the globe in the fourth generation. A single
plant of another orchid might bear seventy-four millions of seeds:
surely an ample provision for a struggle for existence, and selection
and survival of the fittest. But, as Darwin remarks, profuse expenditure
is nothing unusual in nature, and it appears to be more profitable for a
plant to yield a few cross-fertilised than many self-fertilised seeds.
Darwin impresses forcibly on his readers the endless diversity of
structures, and the prodigality of resources displayed for gaining the
same end, the fertilisation of one flower by pollen from another plant.
"The more I study nature," he says, "the more I become impressed with
ever-increasing force that the contrivances and beautiful adaptations
slowly acquired through each part occasionally varying in a slight
degree ... transcend in an incomparable manner the contrivances and
adaptations which the most fertile imagination of man could invent."
Finally he concludes: "It is hardly an exaggeration to say that nature
tells us, in the most emphatic manner, that she abhors perpetual
self-fertilisation"; and thus was announced a new doctrine in botany. A
second much-improved edition of this book appeared in 1877.
In 1864, in presenting the Copley medal of the Royal Society to the
author of the "Origin of Species," Major-General Sabine, the President,
entered into a full description of the merits of his works, "stamped
throughout with the impress of the closest attention to minute
details and accuracy of observation, combined with large powers of
generalisation." The award, while highly eulogising the "Origin," was
not however based upon it, but on the more recent botanical writings.
"The Fertilisation of Orchids" was described as perhaps the most
masterly treatise on any branch of vegetable physiology that had ever
appeared; and the fact was justly emphasised that all Darwin's botanical
discoveries had been obtained by the study of some of the most familiar
and conspicuous of our native plants, and some of the best-known and
easily-procured cultivated exotics.
In 1865 appeared another work from the Darwinian treasury, but in this
case it was at first restricted to the Journal of the Linnean Society
(vol. ix.), and was not made generally available till the second edition
was published separately in 1875. "The Movements and Habits of Climbing
Plants" described in the first place the twining of the hop plant,
studied by night and day continuously, in a well-warmed room, to which
the author was confined by illness. Again and again were different
species of plants watched, and the periods in which their shoots
revolved noted. The clematises, tropæolums, solanums, gloriosa lilies
among leaf-climbing plants; the bignonias, cobæas, bryonies, vines,
passion flowers, and other tendril-bearing plants; the ivy, and other
root and hook climbers were carefully studied; and botanists for the
first time realised fully the advantages which climbing plants possess
in the struggle for existence. The climbing faculty depends on a
sensitiveness to contact with any firm support, and a most interesting
series of modifications has probably, as Darwin suggests, led to the
present development of climbing organs, by the spontaneous movement of
young shoots and other organs, and by unequal growth.
In concluding, the author made some most profoundly suggestive remarks,
which went far to revolutionise our conception of plants. "It has often
been vaguely asserted that plants are distinguished from animals by not
having the power of movement. It should rather be said that plants
acquire and display this power only when it is of some advantage to
them; this being of comparatively rare occurrence, as they are affixed
to the ground, and food is brought to them by the air and rain. We see
how high in the scale of organisation a plant may rise, when we look at
one of the more perfect tendril-bearers. It first places its tendrils
ready for action, as a polypus places its tentacula. If the tendril be
displaced, it is acted on by the force of gravity, and rights itself. It
is acted on by the light, and bends towards or from it, or disregards
it, which ever may be most advantageous. During several days the
tendrils, or internodes, or both, spontaneously revolve with a steady
motion. The tendril strikes some object, and quickly curls round and
firmly grasps it. In the course of some hours it contracts into a spire,
dragging up the stem, and forming an excellent spring. All movements now
cease. By growth the tissues soon become wonderfully strong and durable.
The tendril has done its work, and has done it in an admirable manner."
The labour of revising the successive editions of the "Origin of
Species," together with prolonged ill-health, delayed the fulfilment of
the promise given in that work, that the facts upon which it was based
should be published. It was not till 1868 that the first instalment,
"The Variation of Animals and Plants under Domestication," was given to
the world, in two large volumes, with numerous illustrations. The
author's design was to discuss in a second work the variability of
organic beings in a state of nature, and the conversion of varieties
into species, the struggle for existence and the operation of natural
selection, and the principal objections to the theory, including
questions of instinct and hybridisation. In a third work it was intended
to test the principle of natural selection by the extent to which it
explains the geological succession of organic beings, their distribution
in past and present times, and their mutual affinities and homologies.
The two latter works were never completed, in consequence of ill-health,
and the labour involved in dealing with objections to and new facts in
support of the "Origin," and of the other works which at various times
it became important to complete. But many portions of these subjects
were admirably dealt with by disciples. In some cases Darwin's views led
to the rapid growth of a new science, such as that of comparative
embryology, and it would not have been possible for him to cope with and
interpret the multitude of new and astonishing facts discovered, which
changed the face of organic nature as viewed by biologists. By doing
each day the work which seemed most necessary, and which he could best
do, Darwin managed, in spite of his infirmity of constitution, to
complete a larger body of original work, both in experiment and in
thought, together with a greater quantity of bibliographical study and
collation of observed facts, than any Englishman perhaps has ever done.
The valuable book on "Variation" records and systematises a vast number
of facts respecting all our principal domestic animals and cultivated
plants. It gives evidence of wide reading, as well as great diligence in
writing letters of inquiry to all living authorities who could give
accurate information. Very many visits were paid to zoological gardens,
breeders' establishments, nursery grounds, &c.; and the preparation of
skulls, skins, &c., was a frequent occurrence in the Darwinian
laboratory. To take the case of rabbits alone, which occupied but a
fraction of the time devoted to pigeons: over twenty works are quoted
for historical facts, skeletons of various rabbits were prepared and
exhaustively compared, the effects of use and disuse of parts traced,
most careful measurements are given, and a list of the modifications
which domestic rabbits have undergone, with the probable causes,
concludes the chapter. As to pigeons, no pigeon-fancier ought to be
without the book, for never assuredly was a sporting topic treated by so
great a thinker and so admirably. The numerous experiments in crossing
different breeds, and the results obtained, make this one of the most
instructive books for all breeders. It would seem desirable that this
portion of the book should be issued in a separate form. Again, when we
turn to the sections on plants we see how indefatigable Darwin was, for
he tells us that he cultivated fifty-four varieties of gooseberries
alone, and compared them throughout in flower and fruit.
The chapters on Inheritance, and on Reversion to ancestral characters,
or atavism, are profoundly suggestive. What can be more wonderful, the
author asks, than that some trifling peculiarity should be transmitted
through a long course of development, and ultimately reappear in the
offspring when mature or even when old? Nevertheless, the real subject
of surprise is not that a character should be inherited, but that any
should ever fail to be inherited. Gradually leading up to the important
hypothesis with which the work closes, he observes that to adequately
explain the numerous characters that reappear after intervals of one or
more generations, we must believe that a vast number of characters,
capable of evolution, lie hidden in every organic being. "The
fertilised germ of one of the higher animals, subjected as it is to so
vast a series of changes from the germinal cell to old age--incessantly
agitated by what Quatrefages well calls the _tourbillon vital_--is
perhaps the most wonderful object in nature. It is probable that hardly
a change of any kind affects either parent, without some mark being left
on the germ. But on the doctrine of reversion the germ becomes a far
more marvellous object, for, besides the visible changes to which it is
subjected, we must believe that it is crowded with invisible characters,
proper to both sexes, to both the right and left side of the body, and
to a long line of male and female ancestors separated by hundreds or
even thousands of generations from the present time; and these
characters, like those written on paper with invisible ink, all lie
ready to be evolved under certain known or unknown conditions."
Through a further discussion of many deeply interesting facts, about the
intercrossing of breeds and species, and about the causes of
variability, we pass to the hypothesis of pangenesis, which, briefly
stated, supposes that the cells or units of the body are perpetually
throwing off minute granules or gemmules, which accumulate in the
reproductive system, and may, instead of developing in the next
generation, be transmitted in a dormant state through more than one
generation and then be developed. Combination in various degrees between
these gemmules is supposed to influence their appearance or
non-appearance in the offspring at various stages.
This hypothesis certainly gives a picture of a possible mode of
accounting for many peculiarities shown by living organisms. Although
not generally accepted, it has certainly not been disproved. Mr. Grant
Allen's opinion that it is Darwin's "one conspicuous failure," and that
it is "crude and essentially unphilosophic," must be discounted by his
known devotion to Mr. Herbert Spencer's philosophy. If Darwin had been a
specialist in modern physiology, he might, perhaps, have expressed his
hypothesis in a more persuasive form; but Weismann's germ plasma theory
is the only alternative one hitherto suggested in place of it.