aviary.
I have discussed the probable origin of domestic pigeons at some, yet quite insufficient, length; because when
I first kept pigeons and watched the several kinds, knowing well how true they bred, I felt fully as much
difficulty in believing that they could ever have descended from a common parent, as any naturalist could in
coming to a similar conclusion in regard to the many species of finches, or other large groups of birds, in
nature. One circumstance has struck me much; namely, that all the breeders of the various domestic animals
and the cultivators of plants, with whom I have ever conversed, or whose treatises I have read, are firmly
convinced that the several breeds to which each has attended, are descended from so many aboriginally
distinct species. Ask, as I have asked, a celebrated raiser of Hereford cattle, whether his cattle might not have
descended from long horns, and he will laugh you to scorn. I have never met a pigeon, or poultry, or duck, or
rabbit fancier, who was not fully convinced that each main breed was descended from a distinct species. Van
Mons, in his treatise on pears and apples, shows how utterly he disbelieves that the several sorts, for instance a
Ribston-pippin or Codlin-apple, could ever have proceeded from the seeds of the same tree. Innumerable
other examples could be given. The explanation, I think, is simple: from long-continued study they are
strongly impressed with the differences between the several races; and though they well know that each race
varies slightly, for they win their prizes by selecting such slight differences, yet they ignore all general
arguments, and refuse to sum up in their minds slight differences accumulated during many successive
generations. May not those naturalists who, knowing far less of the laws of inheritance than does the breeder,
and knowing no more than he does of the intermediate links in the long lines of descent, yet admit that many
of our domestic races have descended from the same parents--may they not learn a lesson of caution, when
they deride the idea of species in a state of nature being lineal descendants of other species?
SELECTION.
Let us now briefly consider the steps by which domestic races have been produced, either from one or from
several allied species. Some little effect may, perhaps, be attributed to the direct action of the external
conditions of life, and some little to habit; but he would be a bold man who would account by such agencies
for the differences of a dray and race horse, a greyhound and bloodhound, a carrier and tumbler pigeon. One
of the most remarkable features in our domesticated races is that we see in them adaptation, not indeed to the
animal's or plant's own good, but to man's use or fancy. Some variations useful to him have probably arisen
suddenly, or by one step; many botanists, for instance, believe that the fuller's teazle, with its hooks, which
cannot be rivalled by any mechanical contrivance, is only a variety of the wild Dipsacus; and this amount of
change may have suddenly arisen in a seedling. So it has probably been with the turnspit dog; and this is
known to have been the case with the ancon sheep. But when we compare the dray-horse and race-horse, the
dromedary and camel, the various breeds of sheep fitted either for cultivated land or mountain pasture, with
the wool of one breed good for one purpose, and that of another breed for another purpose; when we compare
the many breeds of dogs, each good for man in very different ways; when we compare the game-cock, so
pertinacious in battle, with other breeds so little quarrelsome, with "everlasting layers" which never desire to
sit, and with the bantam so small and elegant; when we compare the host of agricultural, culinary, orchard,
and flower-garden races of plants, most useful to man at different seasons and for different purposes, or so
beautiful in his eyes, we must, I think, look further than to mere variability. We cannot suppose that all the
breeds were suddenly produced as perfect and as useful as we now see them; indeed, in several cases, we
know that this has not been their history. The key is man's power of accumulative selection: nature gives
successive variations; man adds them up in certain directions useful to him. In this sense he may be said to
make for himself useful breeds.
The great power of this principle of selection is not hypothetical. It is certain that several of our eminent
breeders have, even within a single lifetime, modified to a large extent some breeds of cattle and sheep. In
order fully to realise what they have done, it is almost necessary to read several of the many treatises devoted
to this subject, and to inspect the animals. Breeders habitually speak of an animal's organisation as something
quite plastic, which they can model almost as they please. If I had space I could quote numerous passages tothis effect from highly competent authorities. Youatt, who was probably better acquainted with the works of
agriculturalists than almost any other individual, and who was himself a very good judge of an animal, speaks
of the principle of selection as "that which enables the agriculturist, not only to modify the character of his
flock, but to change it altogether. It is the magician's wand, by means of which he may summon into life
whatever form and mould he pleases." Lord Somerville, speaking of what breeders have done for sheep,
says:--"It would seem as if they had chalked out upon a wall a form perfect in itself, and then had given it
existence." That most skilful breeder, Sir John Sebright, used to say, with respect to pigeons, that "he would
produce any given feather in three years, but it would take him six years to obtain head and beak." In Saxony
the importance of the principle of selection in regard to merino sheep is so fully recognised, that men follow it
as a trade: the sheep are placed on a table and are studied, like a picture by a connoisseur; this is done three
times at intervals of months, and the sheep are each time marked and classed, so that the very best may
ultimately be selected for breeding.
What English breeders have actually effected is proved by the enormous prices given for animals with a good
pedigree; and these have now been exported to almost every quarter of the world. The improvement is by no
means generally due to crossing different breeds; all the best breeders are strongly opposed to this practice,
except sometimes amongst closely allied sub-breeds. And when a cross has been made, the closest selection is
far more indispensable even than in ordinary cases. If selection consisted merely in separating some very
distinct variety, and breeding from it, the principle would be so obvious as hardly to be worth notice; but its
importance consists in the great effect produced by the accumulation in one direction, during successive
generations, of differences absolutely inappreciable by an uneducated eye--differences which I for one have
vainly attempted to appreciate. Not one man in a thousand has accuracy of eye and judgment sufficient to
become an eminent breeder. If gifted with these qualities, and he studies his subject for years, and devotes his
lifetime to it with indomitable perseverance, he will succeed, and may make great improvements; if he wants
any of these qualities, he will assuredly fail. Few would readily believe in the natural capacity and years of
practice requisite to become even a skilful pigeon-fancier.
The same principles are followed by horticulturists; but the variations are here often more abrupt. No one
supposes that our choicest productions have been produced by a single variation from the aboriginal stock.
We have proofs that this is not so in some cases, in which exact records have been kept; thus, to give a very
trifling instance, the steadily-increasing size of the common gooseberry may be quoted. We see an astonishing
improvement in many florists' flowers, when the flowers of the present day are compared with drawings made
only twenty or thirty years ago. When a race of plants is once pretty well established, the seed-raisers do not
pick out the best plants, but merely go over their seed-beds, and pull up the "rogues," as they call the plants
that deviate from the proper standard. With animals this kind of selection is, in fact, also followed; for hardly
any one is so careless as to allow his worst animals to breed.
In regard to plants, there is another means of observing the accumulated effects of selection--namely, by
comparing the diversity of flowers in the different varieties of the same species in the flower-garden; the
diversity of leaves, pods, or tubers, or whatever part is valued, in the kitchen-garden, in comparison with the
flowers of the same varieties; and the diversity of fruit of the same species in the orchard, in comparison with
the leaves and flowers of the same set of varieties. See how different the leaves of the cabbage are, and how
extremely alike the flowers; how unlike the flowers of the heartsease are, and how alike the leaves; how much
the fruit of the different kinds of gooseberries differ in size, colour, shape, and hairiness, and yet the flowers
present very slight differences. It is not that the varieties which differ largely in some one point do not differ
at all in other points; this is hardly ever, perhaps never, the case. The laws of correlation of growth, the
importance of which should never be overlooked, will ensure some differences; but, as a general rule, I cannot
doubt that the continued selection of slight variations, either in the leaves, the flowers, or the fruit, will
produce races differing from each other chiefly in these characters.
It may be objected that the principle of selection has been reduced to methodical practice for scarcely more
than three-quarters of a century; it has certainly been more attended to of late years, and many treatises have been published on the subject; and the result, I may add, has been, in a corresponding degree, rapid and
important. But it is very far from true that the principle is a modern discovery. I could give several references
to the full acknowledgment of the importance of the principle in works of high antiquity. In rude and
barbarous periods of English history choice animals were often imported, and laws were passed to prevent
their exportation: the destruction of horses under a certain size was ordered, and this may be compared to the
"roguing" of plants by nurserymen. The principle of selection I find distinctly given in an ancient Chinese
encyclopaedia. Explicit rules are laid down by some of the Roman classical writers. From passages in
Genesis, it is clear that the colour of domestic animals was at that early period attended to. Savages now
sometimes cross their dogs with wild canine animals, to improve the breed, and they formerly did so, as is
attested by passages in Pliny. The savages in South Africa match their draught cattle by colour, as do some of
the Esquimaux their teams of dogs. Livingstone shows how much good domestic breeds are valued by the
negroes of the interior of Africa who have not associated with Europeans. Some of these facts do not show
actual selection, but they show that the breeding of domestic animals was carefully attended to in ancient
times, and is now attended to by the lowest savages. It would, indeed, have been a strange fact, had attention
not been paid to breeding, for the inheritance of good and bad qualities is so obvious.
At the present time, eminent breeders try by methodical selection, with a distinct object in view, to make a
new strain or sub-breed, superior to anything existing in the country. But, for our purpose, a kind of Selection,
which may be called Unconscious, and which results from every one trying to possess and breed from the best
individual animals, is more important. Thus, a man who intends keeping pointers naturally tries to get as good
dogs as he can, and afterwards breeds from his own best dogs, but he has no wish or expectation of
permanently altering the breed. Nevertheless I cannot doubt that this process, continued during centuries,
would improve and modify any breed, in the same way as Bakewell, Collins, etc., by this very same process,
only carried on more methodically, did greatly modify, even during their own lifetimes, the forms and
qualities of their cattle. Slow and insensible changes of this kind could never be recognised unless actual
measurements or careful drawings of the breeds in question had been made long ago, which might serve for
comparison. In some cases, however, unchanged or but little changed individuals of the same breed may be
found in less civilised districts, where the breed has been less improved. There is reason to believe that King
Charles's spaniel has been unconsciously modified to a large extent since the time of that monarch. Some
highly competent authorities are convinced that the setter is directly derived from the spaniel, and has
probably been slowly altered from it. It is known that the English pointer has been greatly changed within the
last century, and in this case the change has, it is believed, been chiefly effected by crosses with the
fox-hound; but what concerns us is, that the change has been effected unconsciously and gradually, and yet so
effectually, that, though the old Spanish pointer certainly came from Spain, Mr. Borrow has not seen, as I am
informed by him, any native dog in Spain like our pointer.
By a similar process of selection, and by careful training, the whole body of English racehorses have come to
surpass in fleetness and size the parent Arab stock, so that the latter, by the regulations for the Goodwood
Races, are favoured in the weights they carry. Lord Spencer and others have shown how the cattle of England
have increased in weight and in early maturity, compared with the stock formerly kept in this country. By
comparing the accounts given in old pigeon treatises of carriers and tumblers with these breeds as now
existing in Britain, India, and Persia, we can, I think, clearly trace the stages through which they have
insensibly passed, and come to differ so greatly from the rock-pigeon.
Youatt gives an excellent illustration of the effects of a course of selection, which may be considered as
unconsciously followed, in so far that the breeders could never have expected or even have wished to have
produced the result which ensued--namely, the production of two distinct strains. The two flocks of Leicester
sheep kept by Mr. Buckley and Mr. Burgess, as Mr. Youatt remarks, "have been purely bred from the original
stock of Mr. Bakewell for upwards of fifty years. There is not a suspicion existing in the mind of any one at
all acquainted with the subject that the owner of either of them has deviated in any one instance from the pure
blood of Mr. Bakewell's flock, and yet the difference between the sheep possessed by these two gentlemen is
so great that they have the appearance of being quite different varieties."
If there exist savages so barbarous as never to think of the inherited character of the offspring of their
domestic animals, yet any one animal particularly useful to them, for any special purpose, would be carefully
preserved during famines and other accidents, to which savages are so liable, and such choice animals would
thus generally leave more offspring than the inferior ones; so that in this case there would be a kind of
unconscious selection going on. We see the value set on animals even by the barbarians of Tierra del Fuego,
by their killing and devouring their old women, in times of dearth, as of less value than their dogs.
In plants the same gradual process of improvement, through the occasional preservation of the best
individuals, whether or not sufficiently distinct to be ranked at their first appearance as distinct varieties, and
whether or not two or more species or races have become blended together by crossing, may plainly be
recognised in the increased size and beauty which we now see in the varieties of the heartsease, rose,
pelargonium, dahlia, and other plants, when compared with the older varieties or with their parent-stocks. No
one would ever expect to get a first-rate heartsease or dahlia from the seed of a wild plant. No one would
expect to raise a first-rate melting pear from the seed of a wild pear, though he might succeed from a poor
seedling growing wild, if it had come from a garden-stock. The pear, though cultivated in classical times,
appears, from Pliny's description, to have been a fruit of very inferior quality. I have seen great surprise
expressed in horticultural works at the wonderful skill of gardeners, in having produced such splendid results
from such poor materials; but the art, I cannot doubt, has been simple, and, as far as the final result is
concerned, has been followed almost unconsciously. It has consisted in always cultivating the best known
variety, sowing its seeds, and, when a slightly better variety has chanced to appear, selecting it, and so
onwards. But the gardeners of the classical period, who cultivated the best pear they could procure, never
thought what splendid fruit we should eat; though we owe our excellent fruit, in some small degree, to their
having naturally chosen and preserved the best varieties they could anywhere find.
A large amount of change in our cultivated plants, thus slowly and unconsciously accumulated, explains, as I
believe, the well-known fact, that in a vast number of cases we cannot recognise, and therefore do not know,
the wild parent-stocks of the plants which have been longest cultivated in our flower and kitchen gardens. If it
has taken centuries or thousands of years to improve or modify most of our plants up to their present standard
of usefulness to man, we can understand how it is that neither Australia, the Cape of Good Hope, nor any
other region inhabited by quite uncivilised man, has afforded us a single plant worth culture. It is not that
these countries, so rich in species, do not by a strange chance possess the aboriginal stocks of any useful
plants, but that the native plants have not been improved by continued selection up to a standard of perfection
comparable with that given to the plants in countries anciently civilised.
In regard to the domestic animals kept by uncivilised man, it should not be overlooked that they almost
always have to struggle for their own food, at least during certain seasons. And in two countries very
differently circumstanced, individuals of the same species, having slightly different constitutions or structure,
would often succeed better in the one country than in the other, and thus by a process of "natural selection," as
will hereafter be more fully explained, two sub-breeds might be formed. This, perhaps, partly explains what
has been remarked by some authors, namely, that the varieties kept by savages have more of the character of
species than the varieties kept in civilised countries.
On the view here given of the all-important part which selection by man has played, it becomes at once
obvious, how it is that our domestic races show adaptation in their structure or in their habits to man's wants
or fancies. We can, I think, further understand the frequently abnormal character of our domestic races, and
likewise their differences being so great in external characters and relatively so slight in internal parts or
organs. Man can hardly select, or only with much difficulty, any deviation of structure excepting such as is
externally visible; and indeed he rarely cares for what is internal. He can never act by selection, excepting on
variations which are first given to him in some slight degree by nature. No man would ever try to make a
fantail, till he saw a pigeon with a tail developed in some slight degree in an unusual manner, or a pouter till
he saw a pigeon with a crop of somewhat unusual size; and the more abnormal or unusual any character was
when it first appeared, the more likely it would be to catch his attention. But to use such an expression as
trying to make a fantail, is, I have no doubt, in most cases, utterly incorrect. The man who first selected a
pigeon with a slightly larger tail, never dreamed what the descendants of that pigeon would become through
long-continued, partly unconscious and partly methodical selection. Perhaps the parent bird of all fantails had
only fourteen tail-feathers somewhat expanded, like the present Java fantail, or like individuals of other and
distinct breeds, in which as many as seventeen tail-feathers have been counted. Perhaps the first pouter-pigeon
did not inflate its crop much more than the turbit now does the upper part of its oesophagus,--a habit which is
disregarded by all fanciers, as it is not one of the points of the breed.
Nor let it be thought that some great deviation of structure would be necessary to catch the fancier's eye: he
perceives extremely small differences, and it is in human nature to value any novelty, however slight, in one's
own possession. Nor must the value which would formerly be set on any slight differences in the individuals
of the same species, be judged of by the value which would now be set on them, after several breeds have
once fairly been established. Many slight differences might, and indeed do now, arise amongst pigeons, which
are rejected as faults or deviations from the standard of perfection of each breed. The common goose has not
given rise to any marked varieties; hence the Thoulouse and the common breed, which differ only in colour,
that most fleeting of characters, have lately been exhibited as distinct at our poultry-shows.
I think these views further explain what has sometimes been noticed--namely that we know nothing about the
origin or history of any of our domestic breeds. But, in fact, a breed, like a dialect of a language, can hardly be
said to have had a definite origin. A man preserves and breeds from an individual with some slight deviation
of structure, or takes more care than usual in matching his best animals and thus improves them, and the
improved individuals slowly spread in the immediate neighbourhood. But as yet they will hardly have a
distinct name, and from being only slightly valued, their history will be disregarded. When further improved
by the same slow and gradual process, they will spread more widely, and will get recognised as something
distinct and valuable, and will then probably first receive a provincial name. In semi-civilised countries, with
little free communication, the spreading and knowledge of any new sub-breed will be a slow process. As soon
as the points of value of the new sub-breed are once fully acknowledged, the principle, as I have called it, of
unconscious selection will always tend,--perhaps more at one period than at another, as the breed rises or falls
in fashion,--perhaps more in one district than in another, according to the state of civilisation of the
inhabitants--slowly to add to the characteristic features of the breed, whatever they may be. But the chance
will be infinitely small of any record having been preserved of such slow, varying, and insensible changes.
I must now say a few words on the circumstances, favourable, or the reverse, to man's power of selection. A
high degree of variability is obviously favourable, as freely giving the materials for selection to work on; not
that mere individual differences are not amply sufficient, with extreme care, to allow of the accumulation of a
large amount of modification in almost any desired direction. But as variations manifestly useful or pleasing
to man appear only occasionally, the chance of their appearance will be much increased by a large number of
individuals being kept; and hence this comes to be of the highest importance to success. On this principle
Marshall has remarked, with respect to the sheep of parts of Yorkshire, that "as they generally belong to poor
people, and are mostly IN SMALL LOTS, they never can be improved." On the other hand, nurserymen, from
raising large stocks of the same plants, are generally far more successful than amateurs in getting new and
valuable varieties. The keeping of a large number of individuals of a species in any country requires that the
species should be placed under favourable conditions of life, so as to breed freely in that country. When the
individuals of any species are scanty, all the individuals, whatever their quality may be, will generally be
allowed to breed, and this will effectually prevent selection. But probably the most important point of all, is,
that the animal or plant should be so highly useful to man, or so much valued by him, that the closest attention
should be paid to even the slightest deviation in the qualities or structure of each individual. Unless such
attention be paid nothing can be effected. I have seen it gravely remarked, that it was most fortunate that the
strawberry began to vary just when gardeners began to attend closely to this plant. No doubt the strawberry
had always varied since it was cultivated, but the slight varieties had been neglected. As soon, however, as
gardeners picked out individual plants with slightly larger, earlier, or better fruit, and raised seedlings from
them, and again picked out the best seedlings and bred from them, then, there appeared (aided by some crossing with distinct species) those many admirable varieties of the strawberry which have been raised
during the last thirty or forty years.
In the case of animals with separate sexes, facility in preventing crosses is an important element of success in
the formation of new races,--at least, in a country which is already stocked with other races. In this respect
enclosure of the land plays a part. Wandering savages or the inhabitants of open plains rarely possess more
than one breed of the same species. Pigeons can be mated for life, and this is a great convenience to the
fancier, for thus many races may be kept true, though mingled in the same aviary; and this circumstance must
have largely favoured the improvement and formation of new breeds. Pigeons, I may add, can be propagated
in great numbers and at a very quick rate, and inferior birds may be freely rejected, as when killed they serve
for food. On the other hand, cats, from their nocturnal rambling habits, cannot be matched, and, although so
much valued by women and children, we hardly ever see a distinct breed kept up; such breeds as we do
sometimes see are almost always imported from some other country, often from islands. Although I do not
doubt that some domestic animals vary less than others, yet the rarity or absence of distinct breeds of the cat,
the donkey, peacock, goose, etc., may be attributed in main part to selection not having been brought into
play: in cats, from the difficulty in pairing them; in donkeys, from only a few being kept by poor people, and
little attention paid to their breeding; in peacocks, from not being very easily reared and a large stock not kept;
in geese, from being valuable only for two purposes, food and feathers, and more especially from no pleasure
having been felt in the display of distinct breeds.
To sum up on the origin of our Domestic Races of animals and plants. I believe that the conditions of life,
from their action on the reproductive system, are so far of the highest importance as causing variability. I do
not believe that variability is an inherent and necessary contingency, under all circumstances, with all organic
beings, as some authors have thought. The effects of variability are modified by various degrees of inheritance
and of reversion. Variability is governed by many unknown laws, more especially by that of correlation of
growth. Something may be attributed to the direct action of the conditions of life. Something must be
attributed to use and disuse. The final result is thus rendered infinitely complex. In some cases, I do not doubt
that the intercrossing of species, aboriginally distinct, has played an important part in the origin of our
domestic productions. When in any country several domestic breeds have once been established, their
occasional intercrossing, with the aid of selection, has, no doubt, largely aided in the formation of new
sub-breeds; but the importance of the crossing of varieties has, I believe, been greatly exaggerated, both in
regard to animals and to those plants which are propagated by seed. In plants which are temporarily
propagated by cuttings, buds, etc., the importance of the crossing both of distinct species and of varieties is
immense; for the cultivator here quite disregards the extreme variability both of hybrids and mongrels, and the
frequent sterility of hybrids; but the cases of plants not propagated by seed are of little importance to us, for
their endurance is only temporary. Over all these causes of Change I am convinced that the accumulative
action of Selection, whether applied methodically and more quickly, or unconsciously and more slowly, but
more efficiently, is by far the predominant Power.
I have discussed the probable origin of domestic pigeons at some, yet quite insufficient, length; because when
I first kept pigeons and watched the several kinds, knowing well how true they bred, I felt fully as much
difficulty in believing that they could ever have descended from a common parent, as any naturalist could in
coming to a similar conclusion in regard to the many species of finches, or other large groups of birds, in
nature. One circumstance has struck me much; namely, that all the breeders of the various domestic animals
and the cultivators of plants, with whom I have ever conversed, or whose treatises I have read, are firmly
convinced that the several breeds to which each has attended, are descended from so many aboriginally
distinct species. Ask, as I have asked, a celebrated raiser of Hereford cattle, whether his cattle might not have
descended from long horns, and he will laugh you to scorn. I have never met a pigeon, or poultry, or duck, or
rabbit fancier, who was not fully convinced that each main breed was descended from a distinct species. Van
Mons, in his treatise on pears and apples, shows how utterly he disbelieves that the several sorts, for instance a
Ribston-pippin or Codlin-apple, could ever have proceeded from the seeds of the same tree. Innumerable
other examples could be given. The explanation, I think, is simple: from long-continued study they are
strongly impressed with the differences between the several races; and though they well know that each race
varies slightly, for they win their prizes by selecting such slight differences, yet they ignore all general
arguments, and refuse to sum up in their minds slight differences accumulated during many successive
generations. May not those naturalists who, knowing far less of the laws of inheritance than does the breeder,
and knowing no more than he does of the intermediate links in the long lines of descent, yet admit that many
of our domestic races have descended from the same parents--may they not learn a lesson of caution, when
they deride the idea of species in a state of nature being lineal descendants of other species?
SELECTION.
Let us now briefly consider the steps by which domestic races have been produced, either from one or from
several allied species. Some little effect may, perhaps, be attributed to the direct action of the external
conditions of life, and some little to habit; but he would be a bold man who would account by such agencies
for the differences of a dray and race horse, a greyhound and bloodhound, a carrier and tumbler pigeon. One
of the most remarkable features in our domesticated races is that we see in them adaptation, not indeed to the
animal's or plant's own good, but to man's use or fancy. Some variations useful to him have probably arisen
suddenly, or by one step; many botanists, for instance, believe that the fuller's teazle, with its hooks, which
cannot be rivalled by any mechanical contrivance, is only a variety of the wild Dipsacus; and this amount of
change may have suddenly arisen in a seedling. So it has probably been with the turnspit dog; and this is
known to have been the case with the ancon sheep. But when we compare the dray-horse and race-horse, the
dromedary and camel, the various breeds of sheep fitted either for cultivated land or mountain pasture, with
the wool of one breed good for one purpose, and that of another breed for another purpose; when we compare
the many breeds of dogs, each good for man in very different ways; when we compare the game-cock, so
pertinacious in battle, with other breeds so little quarrelsome, with "everlasting layers" which never desire to
sit, and with the bantam so small and elegant; when we compare the host of agricultural, culinary, orchard,
and flower-garden races of plants, most useful to man at different seasons and for different purposes, or so
beautiful in his eyes, we must, I think, look further than to mere variability. We cannot suppose that all the
breeds were suddenly produced as perfect and as useful as we now see them; indeed, in several cases, we
know that this has not been their history. The key is man's power of accumulative selection: nature gives
successive variations; man adds them up in certain directions useful to him. In this sense he may be said to
make for himself useful breeds.
The great power of this principle of selection is not hypothetical. It is certain that several of our eminent
breeders have, even within a single lifetime, modified to a large extent some breeds of cattle and sheep. In
order fully to realise what they have done, it is almost necessary to read several of the many treatises devoted
to this subject, and to inspect the animals. Breeders habitually speak of an animal's organisation as something
quite plastic, which they can model almost as they please. If I had space I could quote numerous passages tothis effect from highly competent authorities. Youatt, who was probably better acquainted with the works of
agriculturalists than almost any other individual, and who was himself a very good judge of an animal, speaks
of the principle of selection as "that which enables the agriculturist, not only to modify the character of his
flock, but to change it altogether. It is the magician's wand, by means of which he may summon into life
whatever form and mould he pleases." Lord Somerville, speaking of what breeders have done for sheep,
says:--"It would seem as if they had chalked out upon a wall a form perfect in itself, and then had given it
existence." That most skilful breeder, Sir John Sebright, used to say, with respect to pigeons, that "he would
produce any given feather in three years, but it would take him six years to obtain head and beak." In Saxony
the importance of the principle of selection in regard to merino sheep is so fully recognised, that men follow it
as a trade: the sheep are placed on a table and are studied, like a picture by a connoisseur; this is done three
times at intervals of months, and the sheep are each time marked and classed, so that the very best may
ultimately be selected for breeding.
What English breeders have actually effected is proved by the enormous prices given for animals with a good
pedigree; and these have now been exported to almost every quarter of the world. The improvement is by no
means generally due to crossing different breeds; all the best breeders are strongly opposed to this practice,
except sometimes amongst closely allied sub-breeds. And when a cross has been made, the closest selection is
far more indispensable even than in ordinary cases. If selection consisted merely in separating some very
distinct variety, and breeding from it, the principle would be so obvious as hardly to be worth notice; but its
importance consists in the great effect produced by the accumulation in one direction, during successive
generations, of differences absolutely inappreciable by an uneducated eye--differences which I for one have
vainly attempted to appreciate. Not one man in a thousand has accuracy of eye and judgment sufficient to
become an eminent breeder. If gifted with these qualities, and he studies his subject for years, and devotes his
lifetime to it with indomitable perseverance, he will succeed, and may make great improvements; if he wants
any of these qualities, he will assuredly fail. Few would readily believe in the natural capacity and years of
practice requisite to become even a skilful pigeon-fancier.
The same principles are followed by horticulturists; but the variations are here often more abrupt. No one
supposes that our choicest productions have been produced by a single variation from the aboriginal stock.
We have proofs that this is not so in some cases, in which exact records have been kept; thus, to give a very
trifling instance, the steadily-increasing size of the common gooseberry may be quoted. We see an astonishing
improvement in many florists' flowers, when the flowers of the present day are compared with drawings made
only twenty or thirty years ago. When a race of plants is once pretty well established, the seed-raisers do not
pick out the best plants, but merely go over their seed-beds, and pull up the "rogues," as they call the plants
that deviate from the proper standard. With animals this kind of selection is, in fact, also followed; for hardly
any one is so careless as to allow his worst animals to breed.
In regard to plants, there is another means of observing the accumulated effects of selection--namely, by
comparing the diversity of flowers in the different varieties of the same species in the flower-garden; the
diversity of leaves, pods, or tubers, or whatever part is valued, in the kitchen-garden, in comparison with the
flowers of the same varieties; and the diversity of fruit of the same species in the orchard, in comparison with
the leaves and flowers of the same set of varieties. See how different the leaves of the cabbage are, and how
extremely alike the flowers; how unlike the flowers of the heartsease are, and how alike the leaves; how much
the fruit of the different kinds of gooseberries differ in size, colour, shape, and hairiness, and yet the flowers
present very slight differences. It is not that the varieties which differ largely in some one point do not differ
at all in other points; this is hardly ever, perhaps never, the case. The laws of correlation of growth, the
importance of which should never be overlooked, will ensure some differences; but, as a general rule, I cannot
doubt that the continued selection of slight variations, either in the leaves, the flowers, or the fruit, will
produce races differing from each other chiefly in these characters.
It may be objected that the principle of selection has been reduced to methodical practice for scarcely more
than three-quarters of a century; it has certainly been more attended to of late years, and many treatises have been published on the subject; and the result, I may add, has been, in a corresponding degree, rapid and
important. But it is very far from true that the principle is a modern discovery. I could give several references
to the full acknowledgment of the importance of the principle in works of high antiquity. In rude and
barbarous periods of English history choice animals were often imported, and laws were passed to prevent
their exportation: the destruction of horses under a certain size was ordered, and this may be compared to the
"roguing" of plants by nurserymen. The principle of selection I find distinctly given in an ancient Chinese
encyclopaedia. Explicit rules are laid down by some of the Roman classical writers. From passages in
Genesis, it is clear that the colour of domestic animals was at that early period attended to. Savages now
sometimes cross their dogs with wild canine animals, to improve the breed, and they formerly did so, as is
attested by passages in Pliny. The savages in South Africa match their draught cattle by colour, as do some of
the Esquimaux their teams of dogs. Livingstone shows how much good domestic breeds are valued by the
negroes of the interior of Africa who have not associated with Europeans. Some of these facts do not show
actual selection, but they show that the breeding of domestic animals was carefully attended to in ancient
times, and is now attended to by the lowest savages. It would, indeed, have been a strange fact, had attention
not been paid to breeding, for the inheritance of good and bad qualities is so obvious.
At the present time, eminent breeders try by methodical selection, with a distinct object in view, to make a
new strain or sub-breed, superior to anything existing in the country. But, for our purpose, a kind of Selection,
which may be called Unconscious, and which results from every one trying to possess and breed from the best
individual animals, is more important. Thus, a man who intends keeping pointers naturally tries to get as good
dogs as he can, and afterwards breeds from his own best dogs, but he has no wish or expectation of
permanently altering the breed. Nevertheless I cannot doubt that this process, continued during centuries,
would improve and modify any breed, in the same way as Bakewell, Collins, etc., by this very same process,
only carried on more methodically, did greatly modify, even during their own lifetimes, the forms and
qualities of their cattle. Slow and insensible changes of this kind could never be recognised unless actual
measurements or careful drawings of the breeds in question had been made long ago, which might serve for
comparison. In some cases, however, unchanged or but little changed individuals of the same breed may be
found in less civilised districts, where the breed has been less improved. There is reason to believe that King
Charles's spaniel has been unconsciously modified to a large extent since the time of that monarch. Some
highly competent authorities are convinced that the setter is directly derived from the spaniel, and has
probably been slowly altered from it. It is known that the English pointer has been greatly changed within the
last century, and in this case the change has, it is believed, been chiefly effected by crosses with the
fox-hound; but what concerns us is, that the change has been effected unconsciously and gradually, and yet so
effectually, that, though the old Spanish pointer certainly came from Spain, Mr. Borrow has not seen, as I am
informed by him, any native dog in Spain like our pointer.
By a similar process of selection, and by careful training, the whole body of English racehorses have come to
surpass in fleetness and size the parent Arab stock, so that the latter, by the regulations for the Goodwood
Races, are favoured in the weights they carry. Lord Spencer and others have shown how the cattle of England
have increased in weight and in early maturity, compared with the stock formerly kept in this country. By
comparing the accounts given in old pigeon treatises of carriers and tumblers with these breeds as now
existing in Britain, India, and Persia, we can, I think, clearly trace the stages through which they have
insensibly passed, and come to differ so greatly from the rock-pigeon.
Youatt gives an excellent illustration of the effects of a course of selection, which may be considered as
unconsciously followed, in so far that the breeders could never have expected or even have wished to have
produced the result which ensued--namely, the production of two distinct strains. The two flocks of Leicester
sheep kept by Mr. Buckley and Mr. Burgess, as Mr. Youatt remarks, "have been purely bred from the original
stock of Mr. Bakewell for upwards of fifty years. There is not a suspicion existing in the mind of any one at
all acquainted with the subject that the owner of either of them has deviated in any one instance from the pure
blood of Mr. Bakewell's flock, and yet the difference between the sheep possessed by these two gentlemen is
so great that they have the appearance of being quite different varieties."
If there exist savages so barbarous as never to think of the inherited character of the offspring of their
domestic animals, yet any one animal particularly useful to them, for any special purpose, would be carefully
preserved during famines and other accidents, to which savages are so liable, and such choice animals would
thus generally leave more offspring than the inferior ones; so that in this case there would be a kind of
unconscious selection going on. We see the value set on animals even by the barbarians of Tierra del Fuego,
by their killing and devouring their old women, in times of dearth, as of less value than their dogs.
In plants the same gradual process of improvement, through the occasional preservation of the best
individuals, whether or not sufficiently distinct to be ranked at their first appearance as distinct varieties, and
whether or not two or more species or races have become blended together by crossing, may plainly be
recognised in the increased size and beauty which we now see in the varieties of the heartsease, rose,
pelargonium, dahlia, and other plants, when compared with the older varieties or with their parent-stocks. No
one would ever expect to get a first-rate heartsease or dahlia from the seed of a wild plant. No one would
expect to raise a first-rate melting pear from the seed of a wild pear, though he might succeed from a poor
seedling growing wild, if it had come from a garden-stock. The pear, though cultivated in classical times,
appears, from Pliny's description, to have been a fruit of very inferior quality. I have seen great surprise
expressed in horticultural works at the wonderful skill of gardeners, in having produced such splendid results
from such poor materials; but the art, I cannot doubt, has been simple, and, as far as the final result is
concerned, has been followed almost unconsciously. It has consisted in always cultivating the best known
variety, sowing its seeds, and, when a slightly better variety has chanced to appear, selecting it, and so
onwards. But the gardeners of the classical period, who cultivated the best pear they could procure, never
thought what splendid fruit we should eat; though we owe our excellent fruit, in some small degree, to their
having naturally chosen and preserved the best varieties they could anywhere find.
A large amount of change in our cultivated plants, thus slowly and unconsciously accumulated, explains, as I
believe, the well-known fact, that in a vast number of cases we cannot recognise, and therefore do not know,
the wild parent-stocks of the plants which have been longest cultivated in our flower and kitchen gardens. If it
has taken centuries or thousands of years to improve or modify most of our plants up to their present standard
of usefulness to man, we can understand how it is that neither Australia, the Cape of Good Hope, nor any
other region inhabited by quite uncivilised man, has afforded us a single plant worth culture. It is not that
these countries, so rich in species, do not by a strange chance possess the aboriginal stocks of any useful
plants, but that the native plants have not been improved by continued selection up to a standard of perfection
comparable with that given to the plants in countries anciently civilised.
In regard to the domestic animals kept by uncivilised man, it should not be overlooked that they almost
always have to struggle for their own food, at least during certain seasons. And in two countries very
differently circumstanced, individuals of the same species, having slightly different constitutions or structure,
would often succeed better in the one country than in the other, and thus by a process of "natural selection," as
will hereafter be more fully explained, two sub-breeds might be formed. This, perhaps, partly explains what
has been remarked by some authors, namely, that the varieties kept by savages have more of the character of
species than the varieties kept in civilised countries.
On the view here given of the all-important part which selection by man has played, it becomes at once
obvious, how it is that our domestic races show adaptation in their structure or in their habits to man's wants
or fancies. We can, I think, further understand the frequently abnormal character of our domestic races, and
likewise their differences being so great in external characters and relatively so slight in internal parts or
organs. Man can hardly select, or only with much difficulty, any deviation of structure excepting such as is
externally visible; and indeed he rarely cares for what is internal. He can never act by selection, excepting on
variations which are first given to him in some slight degree by nature. No man would ever try to make a
fantail, till he saw a pigeon with a tail developed in some slight degree in an unusual manner, or a pouter till
he saw a pigeon with a crop of somewhat unusual size; and the more abnormal or unusual any character was
when it first appeared, the more likely it would be to catch his attention. But to use such an expression as
trying to make a fantail, is, I have no doubt, in most cases, utterly incorrect. The man who first selected a
pigeon with a slightly larger tail, never dreamed what the descendants of that pigeon would become through
long-continued, partly unconscious and partly methodical selection. Perhaps the parent bird of all fantails had
only fourteen tail-feathers somewhat expanded, like the present Java fantail, or like individuals of other and
distinct breeds, in which as many as seventeen tail-feathers have been counted. Perhaps the first pouter-pigeon
did not inflate its crop much more than the turbit now does the upper part of its oesophagus,--a habit which is
disregarded by all fanciers, as it is not one of the points of the breed.
Nor let it be thought that some great deviation of structure would be necessary to catch the fancier's eye: he
perceives extremely small differences, and it is in human nature to value any novelty, however slight, in one's
own possession. Nor must the value which would formerly be set on any slight differences in the individuals
of the same species, be judged of by the value which would now be set on them, after several breeds have
once fairly been established. Many slight differences might, and indeed do now, arise amongst pigeons, which
are rejected as faults or deviations from the standard of perfection of each breed. The common goose has not
given rise to any marked varieties; hence the Thoulouse and the common breed, which differ only in colour,
that most fleeting of characters, have lately been exhibited as distinct at our poultry-shows.
I think these views further explain what has sometimes been noticed--namely that we know nothing about the
origin or history of any of our domestic breeds. But, in fact, a breed, like a dialect of a language, can hardly be
said to have had a definite origin. A man preserves and breeds from an individual with some slight deviation
of structure, or takes more care than usual in matching his best animals and thus improves them, and the
improved individuals slowly spread in the immediate neighbourhood. But as yet they will hardly have a
distinct name, and from being only slightly valued, their history will be disregarded. When further improved
by the same slow and gradual process, they will spread more widely, and will get recognised as something
distinct and valuable, and will then probably first receive a provincial name. In semi-civilised countries, with
little free communication, the spreading and knowledge of any new sub-breed will be a slow process. As soon
as the points of value of the new sub-breed are once fully acknowledged, the principle, as I have called it, of
unconscious selection will always tend,--perhaps more at one period than at another, as the breed rises or falls
in fashion,--perhaps more in one district than in another, according to the state of civilisation of the
inhabitants--slowly to add to the characteristic features of the breed, whatever they may be. But the chance
will be infinitely small of any record having been preserved of such slow, varying, and insensible changes.
I must now say a few words on the circumstances, favourable, or the reverse, to man's power of selection. A
high degree of variability is obviously favourable, as freely giving the materials for selection to work on; not
that mere individual differences are not amply sufficient, with extreme care, to allow of the accumulation of a
large amount of modification in almost any desired direction. But as variations manifestly useful or pleasing
to man appear only occasionally, the chance of their appearance will be much increased by a large number of
individuals being kept; and hence this comes to be of the highest importance to success. On this principle
Marshall has remarked, with respect to the sheep of parts of Yorkshire, that "as they generally belong to poor
people, and are mostly IN SMALL LOTS, they never can be improved." On the other hand, nurserymen, from
raising large stocks of the same plants, are generally far more successful than amateurs in getting new and
valuable varieties. The keeping of a large number of individuals of a species in any country requires that the
species should be placed under favourable conditions of life, so as to breed freely in that country. When the
individuals of any species are scanty, all the individuals, whatever their quality may be, will generally be
allowed to breed, and this will effectually prevent selection. But probably the most important point of all, is,
that the animal or plant should be so highly useful to man, or so much valued by him, that the closest attention
should be paid to even the slightest deviation in the qualities or structure of each individual. Unless such
attention be paid nothing can be effected. I have seen it gravely remarked, that it was most fortunate that the
strawberry began to vary just when gardeners began to attend closely to this plant. No doubt the strawberry
had always varied since it was cultivated, but the slight varieties had been neglected. As soon, however, as
gardeners picked out individual plants with slightly larger, earlier, or better fruit, and raised seedlings from
them, and again picked out the best seedlings and bred from them, then, there appeared (aided by some crossing with distinct species) those many admirable varieties of the strawberry which have been raised
during the last thirty or forty years.
In the case of animals with separate sexes, facility in preventing crosses is an important element of success in
the formation of new races,--at least, in a country which is already stocked with other races. In this respect
enclosure of the land plays a part. Wandering savages or the inhabitants of open plains rarely possess more
than one breed of the same species. Pigeons can be mated for life, and this is a great convenience to the
fancier, for thus many races may be kept true, though mingled in the same aviary; and this circumstance must
have largely favoured the improvement and formation of new breeds. Pigeons, I may add, can be propagated
in great numbers and at a very quick rate, and inferior birds may be freely rejected, as when killed they serve
for food. On the other hand, cats, from their nocturnal rambling habits, cannot be matched, and, although so
much valued by women and children, we hardly ever see a distinct breed kept up; such breeds as we do
sometimes see are almost always imported from some other country, often from islands. Although I do not
doubt that some domestic animals vary less than others, yet the rarity or absence of distinct breeds of the cat,
the donkey, peacock, goose, etc., may be attributed in main part to selection not having been brought into
play: in cats, from the difficulty in pairing them; in donkeys, from only a few being kept by poor people, and
little attention paid to their breeding; in peacocks, from not being very easily reared and a large stock not kept;
in geese, from being valuable only for two purposes, food and feathers, and more especially from no pleasure
having been felt in the display of distinct breeds.
To sum up on the origin of our Domestic Races of animals and plants. I believe that the conditions of life,
from their action on the reproductive system, are so far of the highest importance as causing variability. I do
not believe that variability is an inherent and necessary contingency, under all circumstances, with all organic
beings, as some authors have thought. The effects of variability are modified by various degrees of inheritance
and of reversion. Variability is governed by many unknown laws, more especially by that of correlation of
growth. Something may be attributed to the direct action of the conditions of life. Something must be
attributed to use and disuse. The final result is thus rendered infinitely complex. In some cases, I do not doubt
that the intercrossing of species, aboriginally distinct, has played an important part in the origin of our
domestic productions. When in any country several domestic breeds have once been established, their
occasional intercrossing, with the aid of selection, has, no doubt, largely aided in the formation of new
sub-breeds; but the importance of the crossing of varieties has, I believe, been greatly exaggerated, both in
regard to animals and to those plants which are propagated by seed. In plants which are temporarily
propagated by cuttings, buds, etc., the importance of the crossing both of distinct species and of varieties is
immense; for the cultivator here quite disregards the extreme variability both of hybrids and mongrels, and the
frequent sterility of hybrids; but the cases of plants not propagated by seed are of little importance to us, for
their endurance is only temporary. Over all these causes of Change I am convinced that the accumulative
action of Selection, whether applied methodically and more quickly, or unconsciously and more slowly, but
more efficiently, is by far the predominant Power.
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