market at Conway, in North Wales, and also on the coast of France. The
parasitic worm is the young of a worm which, when adult, lives in the
intestine of carnivorous fishes. It appears that it has to pass from
and with the mussel into shellfish-eating sea fishes, where, although
the mussel is digested, the parasite is not, but grows in size and
alters its shape considerably. Then after a time the worm is swallowed,
with the fish in which it has fixed itself, by sharks, dogfish, and
such fish-eating fishes. In these at last it becomes adult and of some
size, an inch or so long, varying according to the particular kind, and
produces many thousands of eggs, which hatch out as minute creatures
swimming in the sea-water, and fortunate if they fall upon a bed of
mussels. They enter the mussel’s shell and make their way into its
soft substance. A certain number (very few) get encased in the skin
and covered up by pearl-layers, which is the mussel’s way of killing
them and putting them out of mischief. The others which have entered
other regions of the mussel’s body thrive, and have a chance of being
swallowed by a mussel-eating fish, and then a further chance of that
fish being eaten by a shark. If this happens the lucky worm--like the
Italian who gets a winning number in three successive drawings of a
lottery--gains the big prize. He becomes adult and produces innumerable
young, who in their turn enter upon the chanceful career of a mussel
parasite.
Thus we see that a pearl is not only a disease or abnormal growth
caused by a parasite, but is actually an elaborately formed tomb
or sarcophagus, in which the parasite is enclosed layer upon layer.
This mode of disposing of parasites and other intrusive bodies is not
unusual in animals. The terrible little flesh-worm--the Trichina--which
causes the death of rats, pigs, and men who eat raw meat, is sometimes
conquered in this way. It is found in the muscles (flesh) of man
and animals enclosed in little pearl-like sacs, half the size of a
hempseed, and it dies there, unless the invaded animal should die, and
its flesh be eaten (as raw ham for instance) by another animal. The
burying of inconvenient corpses in plaster of paris, corresponding
to pearls as we now know them, has been a method of concealment
occasionally adopted by criminals. On the whole, pearls have not very
pleasant associations.
The history of the special parasitic worm which invades the beautiful
little pearl-oyster of Ceylon has recently been followed out by skilful
naturalists. There, too, a smaller oyster-eating fish of a peculiar
kind, and a larger fish which eats the first fish, are necessary for
the reproduction and multiplication of the pearl-producing parasites.
The new Ceylon Pearl-Fishing Company has, therefore, to see to it that
both these kinds of fish are encouraged to live in the sea near where
the pearl oysters are found, and it is their object to increase the
parasitic disease by which pearls are formed, and ensure an abundance
of parasites.
An interesting new method has been recently applied to the examination
of pearl oysters for pearls. The Rontgen rays are used to produce a
skiagraph (such as surgeons use in searching for a bullet) of the pearl
oysters when brought into harbour. They are thus rapidly examined one
by one, without injury, and the shadow-picture shows the pearl or
pearls inside those oysters which are infected. The pearlless oysters
are returned to the depths of the sea, whence they came--those with
small pearls only are kept in special reserves or sea-lakes, in order
that the pearl may grow in size, whilst only those with good-sized
pearls are opened at once, in order that the pearl may be extracted and
sent to market.
There were great findings of pearls in the fresh-water pearl mussels
of the Scotch rivers in former days. In the last forty years of the
eighteenth century these pearls were exported from Scotland to France
to the value of £100,000.
In the eighteenth century not only did they get their pearls from
European rivers instead of from the East; but, instead of being
excited about the artificial production of diamonds, they were driven
wild with astonishment by the demonstration of the volatilisation of
these stones--the disappearance of diamonds into invisible vapour
when sufficiently heated. That the hardest stone in nature could be
thus dissipated into thin air seemed incredible. On Aug. 10, 1771, a
chemist named Rouelle invited to his laboratory to witness this wonder
a company comprising the Margrave of Baden and the Princess his wife,
the Dukes of Chaulne and of Nivernois, the Marchionesses of Nesle and
of Pons, the Countess of Polignac, and some members of the Academy of
Sciences, including the great chemist Lavoisier. Four diamonds--the
largest belonging to the Count Lauraguais--were submitted before the
eyes of all to the heat of a furnace, and in three hours had completely
evaporated. There was, no doubt, room here for a mystification and for
the abstraction of the diamonds with a view to dishonest appropriation.
But no such purpose existed. The experiment was a genuine one, and
Rouelle and his brother were honest investigators. They established the
fact, now demonstrated as a lecture experiment, that the diamond is
volatilised at very high temperatures. A more celebrated “evaporation”
of diamonds--that which is known as “the affair of the Queen’s
necklace”--took place a few years later in Paris, when no scientific
investigation was connected with the embarrassing disappearance of the
Royal trinket.
35. _A King Who was a Zoologist_
The King of Portugal, Carlos di Braganza, who was assassinated in the
spring of 1908, was one of the most gifted and vigorous men of his age,
fearless and intelligent to a rare degree, good-hearted, and devoted to
the welfare of his people. If any man were justified in having no fear
of outrage because he was conscious that his uprightness was proved and
known to all men, his benevolence experienced by all, his ability and
vast knowledge recognised by all, Dom Carlos was that man. Fanaticism,
however, takes no account of the virtues of its victims. Until society
has invented a method for keeping instruments of destruction out of
the reach of dangerous, more or less maniacal individuals, all those
who excite the fanatic’s brain, even by the excellence and nobility of
their lives, risk death whenever they trust themselves to the tender
mercies of a crowd. Psychology may one day enable us to detect, and
improved supervision of children enable us to segregate before it is
too late, the latent assassins in our midst. If they have not a king as
their quarry their reason is palsied by a president, and were there no
presidents, they would become homicidal in the presence of a prefect or
a policeman--even of a professor.
Some four years ago I had the honour of conducting Dom Carlos round the
Natural History Museum in Cromwell Road. He arrived without attendant
or escort, and I passed two hours alone with him. I had been told that
he was a great shot and fond of natural history, that he played every
athletic game, rode, and swam better than the best, that he was a
fine water-colour painter, a real artist--and a first-rate musician
and singer. I was astonished at his knowledge and personal experience
in natural history. His burly form and bright, honest face gave me a
most agreeable impression, and when he said (as I had been told he
would) to each explanation of a specimen upon which I ventured for
his edification, “I know! I know!” felt that it was true, and that
he really did know. “I have shot thirty of them in the south of my
country,” he said of some rare bird. “I know! I know! I have described
a new species like that in my book on the birds of Portugal. I shall
send it to you!” was his comment on another. When we came to some
wonderful coral-like specimens--sea-pens and sea-feathers, dredged in
the deep sea and preserved in spirits, for exhibition in the Museum--he
said, to my astonishment, “Those are very bad. I get much better than
those in my yacht off the Portuguese coast. I preserve them myself;
it is a real art. I shall send you some.” I said they would be a very
welcome addition. “Yes, I know! I know!” he said. “Would you like some
fishes, too? The Prince of Monaco has some fine things, and he led
me to collect also myself. I have now many things better than his. I
shall send you some fishes, too.” And he did. A few months after his
return to Portugal he sent to the Museum a large collection, preserved
in spirit, which included many very fine and interesting specimens of
deep-water Atlantic fishes; also his work, with coloured plates, on
the Birds of Portugal, and a most remarkable publication on the tunny
fisheries of the South Coast of Portugal--giving a careful survey of
the waters, sea bottom, currents, fauna, and flora in correct, expert
form, such as might issue from a Government Fisheries Board, but in
this case done, as modestly indicated on the title-page, by the Head
of the State himself, “Dom Carlos di Braganza.” He went into the
work-rooms of the Museum, where some new fishes were being drawn, and
conversed with the naturalist in charge, and criticised the drawings.
He saw everything, appreciated everything, and then looking at his
watch, said, “I have only five minutes to get to a lunch party. Thank
you very much for the most delightful time. I should like to stay all
the day; it is a splendid place,” and was off in his brougham.
I exhibited the specimens and books sent by his Majesty for some weeks
in the Central Hall of the museum, before they were incorporated in
the great collection, for I felt that it was a rare and interesting
thing that a king should not merely take a sportsman’s pleasure in
birds, beasts, and fishes, but actually be, so to speak, “one of us”--a
zoologist who discovers, describes, and names new things. The Prince of
Monaco is the only other head of a State who is a serious scientific
naturalist. He has built and endowed a magnificent museum and
laboratory at Monaco, where his skilled assistants carry on researches
and look after the extremely valuable and important collections which
he has himself made in a series of cruises in the Atlantic extending
over many years. He has not only employed capable naturalists to help
him, but is himself the chief authority and an original discoverer in
“oceanography,” the science of the great oceans.
A year or so ago, when Dom Carlos visited Paris, a special fête and
reception was organised in his honour at the “Muséum d’Histoire
Naturelle,” in the Jardin des Plantes. The “Museum” of the Jardin des
Plantes is a very remarkable institution, including a zoological and
botanical garden, laboratories of chemistry, physics, and physiology,
besides the great collections of minerals, fossils, skeletons, and
preserved specimens of animals and plants. It is governed by the
professors and the director who are in charge of the garden, the
laboratories, and the collections, and owes its dignity and its
celebrity to the distinguished men of science who for a century and a
half have made discoveries and taught there. They are not subject to a
board of eminent and wealthy persons, nor is the administration of the
antiquities at the Louvre and of the National Library muddled up with
that of the great scientific workshop of Natural History.
When the President of the Republic conceived the plan of entertaining
the King of Portugal at the Museum of Natural History there were
those who supposed that the Minister of Education would, as a great
State official, be called upon to arrange the proceedings. Nothing of
the sort was done. It was found that the Minister had no authority
in regard to the Museum, which, as an independent State institution,
organised and carried out the reception through its own officers. The
director and professors received President Fallières and the King,
escorted by the troops of the Republic. The garden and buildings
were ablaze with light and colour, and a large company assembled to
take part in the fête. In the great hall of the museum Becquerel,
Moissan, and others showed their most recent discoveries as to radium,
artificial diamonds, and such matters to the King; others exhibited
new birds and fishes, the okapi and newly-discovered fossils, and
briefly explained their history and significance. The King conferred
decorations on the scientific staff, and gave friendly acknowledgments
to all who had thus sought to gratify his special tastes, and prepared
for him a really exceptional gala-demonstration of scientific
discovery. The official “middle-men,” who in other countries contrive
to divert the honour and emoluments due to men of science, to their own
profit, were on this occasion happily kept at a distance.
36. _The Transmission to Offspring of Acquired Qualities_
The cruel fate of Dom Carlos of Portugal naturally enough produced
philosophic and thoughtful articles in some of the journals of the
day. An able writer told his readers that the “kingly caste” has
characteristics peculiar to itself, “which illustrate the Darwinian
law.” He does not say what Darwinian law, and I am afraid he would find
it difficult to do so. He says that people who for centuries have had
their own way (how many kingly families have done so?), who have always
lived on good food and never tasted bad wine, and have constantly
conversed with interesting people (not usually the chance of princes!)
must certainly, if subject to “the laws which govern animal and plant
life,” produce well-marked characteristics in their offspring--and he
goes on to speak of a fine appetite for food (what he describes is
really a morbid condition connected with indigestion) as indigenous
to Royalty, and declares that the gift of recognising faces and
remembering names is “a faculty cultivated by generations of practice.”
One must recognise with satisfaction the desire to explain the facts
and varieties of human life and character by reference to “the laws
which govern animal and plant life.” It is by faithfully and truly
carrying out the inquiries suggested by that desire that the knowledge
which is the sole and absolutely essential condition for the safe
conduct of human life and the increased happiness of human communities,
can be obtained, and by such inquiries only; and, further, only
upon the condition that the investigation is conducted in the true
scientific spirit with accuracy and without prejudice. The remarks upon
the kingly caste which I have quoted above show with what “legerity
and temerity” a clever and respected writer will formulate phrases and
conclusions which are, in face of what Darwin and his successors have
demonstrated, absurdly erroneous, in fact, topsy-turvy as compared with
the reality.
The main doctrine which Darwin and his followers have established is
that neither castes nor families of higher or lower living things,
including man, acquire any new characteristics by exposure to special
circumstances or by consuming finer or coarser food, which can or do
become innate or fixed in the race. The individual may be improved or
depraved, enlarged or enfeebled, by the conditions of his individual
life, but he cannot transmit the qualities--the improvement, the
depravity, the enlargement, or the dwindling--which have been thus
attained by him to his offspring. The race cannot be changed in this
way. All the parents can transmit is the quality which they themselves
have inherited of resisting or of collapsing, of becoming enfeebled,
or of showing strength and vigour, under certain given conditions. The
characteristics of Royalty are not characteristics brought about by the
Royal state, any more than the characteristics of English race-horses
are brought about by the racing state or by life in a breeder’s
stable. The characteristics of Royalty are like those of other living
things, the characteristics of a certain family or blend of families
or strains. Whatever characteristics distinct Royal families have in
common with one another are not due to the existence of a natural law
in virtue of which the occupations and opportunities of the Royal state
produce “faculties” or “characteristics” in the “blood” or “stock.”
Such similarity of characteristics is due either to the similarity of
the demands and conditions of Court life in all parts of Europe, acting
as an educating force on the individual, or to the intermarrying and
consequent blending of family characteristics among a large proportion
of the Royal Houses at present existing.
It is very difficult--indeed impossible until much more is written
and read on the subjects of breeding and of psychology--to persuade
people to abandon the notion that a man who has drunk good wine and
conversed with interesting people will, as a direct result, transmit
something which he has “taken up” or absorbed from the good wine and
the clever people to his offspring, and that a faculty for this or
that art or accomplishment cultivated by generation after generation
is increased thereby, and transferred as it were into the very vitals
of the race--the reproductive germs which each individual has within
him. There is no truth whatever in these fancies. They are popular and
very natural delusions, which are not only devoid of direct proof by
simple observation and experiment, such as that made by all breeders of
stock and by medical men, but are also contrary to the great general
principles which have been found to explain the varied and most
important facts known as to breeding, inheritance, and variation. The
same erroneous theory of inheritance now applied to royalty has been
put forward in regard to the feeble-minded, the ill-grown, and the
incapable at the other end of the social scale.
The only way in which a quality, good or bad, desirable or undesirable,
is intensified, made inherent and dominant in a race or strain or
family, is by selective breeding--selection due to natural rejection
of those individuals not possessing the quality, or to artificial
rejection of such individuals by the stock owner and breeder. No human
maker of breeds--whether of cattle, horses, birds, or plants--ever yet
proceeded by exercising, feeding, educating, or otherwise manipulating
his sires and dams; he simply selects those as parents which by natural
variation have the quality, more or less, which he desires, and he
destroys or sterilises those which fail to satisfy his requirements.
He is perfectly confident that in this way he can ensure the
reproduction and exaggeration or dominance of the characteristics which
he desires; he knows that he cannot obtain a “strain” or “breed” by any
treatment, any feeding, or education of those which are born without
the natural, innate possession of the desired quality, in a more or
less marked degree. Once the characteristic turns up as a congenital
variation, it can be intensified by coupling its possessor with a mate
of like quality; but both sire and dam have to be rigidly selected with
this purpose in view. Such methods are not adopted in human families,
even royal ones.
In considering these questions as to characteristic qualities or want
of qualities in groups and classes of human communities, we see then
that we have in the first instance to distinguish very broadly between
the body or structure of the individual, and the “stirps” or germ of
the race which he carries within him. The former may be vastly changed
for the better or worse as compared with average individuals, without
affecting in any way the latter. The germ is carried by the individual
member of the race in an almost complete state of isolation or safety
from the influences which affect the individual’s structure generally
(his body as distinct from his germinal or reproductive substance)
injuriously or beneficially. The germ varies also, but independently.
That is a matter of primary importance. Equally important in the case
of man is a peculiarity which affects his manifestation of qualities in
a way unknown in any other living thing.
Human society, in more marked and dominating form, in proportion as
it is what we call “civilised,” has created for itself an inheritance
which is not dependent on the variations of strains and the laws
of actual breeding. Over and above--very much above--what each man
inherits in the form of qualities and characteristics of his special
family and stock--is the enormous mass of accumulated experience,
knowledge, tradition, custom, and law--which pervades and envelops,
as it were, the mere physical generations of this or that pullulating
crowd of human individuals. Tradition, at first conveyed by gesture and
imitativeness from parents to offspring, then by word of mouth, then
by writing, and finally by printed record, sanctioned and enforced by
all kinds of persuasion and compulsion--has culminated in an educative
discipline which affects every individual in the community in the
most powerful way--and constitutes an inheritance of a significance
and activity altogether transcending, and independent of that due
to the physical transmission of bodily and mental qualities. Public
opinion, law, knowledge, belief, custom, and habit exist, and pursue
their own course of change, as it were, outside the successive
bodily generations of a population. Yet they determine in very large
measure the characteristics which each class, and the community as a
whole, exhibit. We have to distinguish those results which are due to
physical heredity, similar in man and in animals--from results due
to this all-powerful education peculiar to man--education, which for
civilised man proceeds from almost innumerable sources--from parents,
nurses, playfellows, companions, social, professional, and political
organisations, as well as from the professed teacher, and from the
local peculiarities of the simplest conditions of life. Hence it is
that man inherits very little in the way of ready-made instincts,
tricks of his nervous mechanism--but, on the contrary, has an
enormously long period of individual growth and education, and inherits
“educability” to a degree which varies in every family and race.
To estimate correctly, and so to deal with these various factors
in human life, we require to know in detail the laws of breeding,
heredity, variation, and selection in animals, and, further, the
laws or formulated results of enquiry as to the “educability” of the
human being, the range and the limits of “education,” the relation of
hereditary quality to education, the causes of mental aberration and
defect, of mental qualities of all kinds, the value and the dangers
of all kinds of educational influences, whether physical, social, or
intellectual. These are matters in regard to which there must be in the
future more and more of common knowledge and agreement; at present they
are lightly touched by politicians and journalists in a way which is
inconsistent with a knowledge of the facts or of their importance.
When publicists airily declare that the virtues of kings and the vices
of paupers are both due to the hereditary transmission of characters
acquired by the peculiarities of diet and exercise of the progenitors
of these classes it is time to protest. To cite the name of Darwin
and “the laws which govern animal and plant life,” in support instead
of in condemnation of such baseless fancies, is, one must suppose, an
evidence, not of a desire to mislead, but of a regrettable indifference
to the conclusions of that branch of human knowledge which is of more
importance than any other to the statesman and the philanthropist.
“Selection,” whether due to survival in the struggle for existence or
exercised by man as a “breeder” or “fancier,” is the only way in which
new characteristics, good or bad, can be implanted in a race or stock,
and become part of the hereditary quality of that race or stock. This
applies equally to man and to animals and plants. And this selection is
no temporary or casual thing. It means “the selection for breeding” of
those individuals which spontaneously by the innate variability which
all living things show (so that no two individuals are exactly alike)
have exhibited from birth onwards, more or less clearly, indications
of the characteristic which is to be selected. Nothing done to them
after birth, and not done to others of their family or race, causes the
desired characteristic; it appears unexpectedly, almost unaccountably
as an in-born quality. It may be a slight difference only, not easy
to take note of; but if it enables those who possess it to get the
better of their competitors in the struggle for life, they will survive
and mate and so transmit their characteristic to the next generation,
whilst those who do not possess it and are beaten in life and fail to
obtain food, safety, and mates, will perish and disappear, and their
defective strain will perish with them.
37. _Variation and Selection Among Living Things_