DUCK--GOOSE--PEACOCK--TURKEY--GUINEA-FOWL--CANARY-BIRD--GOLD-FISH--HIVE-
BEES--SILK-MOTHS.
DUCKS, SEVERAL BREEDS OF.
PROGRESS OF DOMESTICATION.
ORIGIN OF FROM THE COMMON WILD-DUCK.
DIFFERENCES IN THE DIFFERENT BREEDS.
OSTEOLOGICAL DIFFERENCES.
EFFECTS OF USE AND DISUSE ON THE LIMB-BONES.
GOOSE, ANCIENTLY DOMESTICATED.
LITTLE VARIATION OF.
SEBASTOPOL BREED.
PEACOCK, ORIGIN OF BLACK-SHOULDERED BREED.
TURKEY, BREEDS OF.
CROSSED WITH THE UNITED STATES SPECIES.
EFFECTS OF CLIMATE ON.
GUINEA-FOWL, CANARY-BIRD, GOLD-FISH, HIVE-BEES.
SILK-MOTHS, SPECIES AND BREEDS OF.
ANCIENTLY DOMESTICATED.
CARE IN THEIR SELECTION.
DIFFERENCES IN THE DIFFERENT RACES.
IN THE EGG, CATERPILLAR, AND COCOON STATES.
INHERITANCE OF CHARACTERS.
IMPERFECT WINGS.
LOST INSTINCTS.
CORRELATED CHARACTERS.
I will, as in previous cases, first briefly describe the chief domestic
breeds of the duck:--
[BREED 1. COMMON DOMESTIC DUCK.
Varies much in colour and in proportions, and differs in instincts and
disposition from the wild duck. There are several sub-breeds:--
1. The Aylesbury, of great size, white, with pale-yellow beak and legs;
abdominal dermal sack largely developed.
2. The Rouen, of great size, coloured like the wild duck, with green or
mottled beak; dermal sack largely developed.
3. Tufted Duck, with a large top-knot of fine downy feathers, supported on
a fleshy mass, with the skull perforated beneath. The top-knot in a duck
which I imported from Holland was two and a half inches in diameter.
4. Labrador (or Canadian, or Buenos Ayres, or East Indian); plumage
entirely black; beak broader, relatively to its length, than in the wild
duck; eggs slightly tinted with black. This sub-breed perhaps ought to be
ranked as a breed; it includes two sub-varieties, one as large as the
common domestic duck, which I have kept alive, and the other smaller and
often capable of flight. (8/1. 'Poultry Chronicle' 1854 volume 2 page 91
and volume 1 page 330.) I presume it is this latter sub-variety which has
been described in France (8/2. Dr. Turral 'Bull. Soc. d'Acclimat.' tome 7
1860 page 541.) as flying well, being rather wild, and when cooked having
the flavour of the wild duck; nevertheless this sub-variety is polygamous,
like other domesticated ducks and unlike the wild duck. These black
Labrador ducks breed true; but a case is given by Dr. Turral of the French
sub-variety producing young with some white feathers on the head and neck,
and with an ochre-coloured patch on the breast.
BREED 2. HOOK-BILLED DUCK.
This bird presents an extraordinary appearance from the downward curvature
of the beak. The head is often tufted. The common colour is white, but some
are coloured like wild ducks. It is an ancient breed, having been noticed
in 1676. (8/3. Willughby's 'Ornithology' by Ray page 381. This breed is
also figured by Albin in 1734 in his 'Nat. Hist. of Birds' volume 2 page
86.) It shows its prolonged domestication by almost incessantly laying
eggs, like the fowls which are called everlasting layers. (8/4. F. Cuvier
in 'Annales du Museum' tome 9 page 128 says that moulting and incubation
alone stops these ducks laying. Mr. B.P. Brent makes a similar remark in
the 'Poultry Chronicle' 1855 volume 3 page 512.)
BREED 3. CALL DUCK.
Remarkable from its small size, and from the extraordinary loquacity of the
female. Beak short. These birds are either white, or coloured like the wild
duck.
BREED 4. PENGUIN DUCK.
This is the most remarkable of all the breeds, and seems to have originated
in the Malayan archipelago. It walks with its body extremely erect, and
with its thin neck stretched straight upwards. Beak rather short. Tail
upturned, including only 18 feathers. Femur and metatarsus elongated.]
Almost all naturalists admit that the several breeds are descended from the
common wild duck (Anas boschas); most fanciers, on the other hand, take as
usual a very different view. (8/5. Rev. E.S. Dixon 'Ornamental and Domestic
Poultry' 1848 page 117. Mr. B.P. Brent in 'Poultry Chronicle' volume 3 1855
page 512.) Unless we deny that domestication, prolonged during centuries,
can affect even such unimportant characters as colour, size, and in a
slight degree proportional dimensions and mental disposition, there is no
reason whatever to doubt that the domestic duck is descended from the
common wild species, for the one differs from the other in no important
character. We have some historical evidence with respect to the period and
progress of the domestication of the duck. It was unknown (8/6. Crawfurd on
the 'Relation of Domesticated Animals to Civilisation' read before the
Brit. Assoc. at Oxford 1860.) to the ancient Egyptians, to the Jews of the
Old Testament, and to the Greeks of the Homeric period. About eighteen
centuries ago Columella (8/7. Dureau de La Malle in 'Annales des Sciences
Nat.' tome 17 page 164; and tome 21 page 55. Rev. E.S. Dixon 'Ornamental
Poultry' page 118. Tame ducks were not known in Aristotle's time, as
remarked by Volz in his 'Beitrage zur Kulturgeschichte' 1852 s. 78.) and
Varro speak of the necessity of keeping ducks in netted enclosures like
other wild fowl, so that at this period there was danger of their flying
away. Moreover, the plan recommended by Columella to those who wish to
increase their stock of ducks, namely, to collect the eggs of the wild bird
and to place them under a hen, shows, as Mr. Dixon remarks, "that the duck
had not at this time become a naturalised and prolific inmate of the Roman
poultry-yard." The origin of the domestic duck from the wild species is
recognised in nearly every language of Europe, as Aldrovandi long ago
remarked, by the same name being applied to both. The wild duck has a wide
range from the Himalayas to North America. It crosses readily with the
domestic bird, and the crossed offspring are perfectly fertile.
Both in North America and Europe the wild duck has been found easy to tame
and breed. In Sweden this experiment was carefully tried by Tiburtius; he
succeeded in rearing wild ducks for three generations, but, though they
were treated like common ducks, they did not vary even in a single feather.
The young birds suffered from being allowed to swim about in cold water
(8/8. I quote this account from 'Die Enten- und Schwanenzucht' Ulm 1828 s.
143. See Audubon 'Ornithological Biography' volume 3 page 168 on the taming
of ducks on the Mississippi. For the same fact in England see Mr. Waterton
in Loudon's 'Mag. of Nat. Hist.' volume 8 1835 page 542; and Mr. St. John
'Wild Sports and Nat. Hist. of the Highlands' 1846 page 129.), as is known
to be the case, though the fact is a strange one, with the young of the
common domestic duck. An accurate and well-known observer in England (8/9.
Mr. E. Hewitt in 'Journal of Horticulture' 1862 page 773; and 1863 page
39.) has described in detail his often repeated and successful experiments
in domesticating the wild duck. Young birds are easily reared from eggs
hatched under a bantam; but to succeed it is indispensable not to place the
eggs of both the wild and tame duck under the same hen, for in this case
"the young wild ducks die off, leaving their more hardy brethren in
undisturbed possession of their foster-mother's care. The difference of
habit at the onset in the newly-hatched ducklings almost entails such a
result to a certainty." The wild ducklings were from the first quite tame
towards those who took care of them as long as they wore the same clothes,
and likewise to the dogs and cats of the house. They would even snap with
their beaks at the dogs, and drive them away from any spot which they
coveted. But they were much alarmed at strange men and dogs. Differently
from what occurred in Sweden, Mr. Hewitt found that his young birds always
changed and deteriorated in character in the course of two or three
generations; notwithstanding that great care was taken to prevent their
crossing with tame ducks. After the third generation his birds lost the
elegant carriage of the wild species, and began to acquire the gait of the
common duck. They increased in size in each generation, and their legs
became less fine. The white collar round the neck of the mallard became
broader and less regular, and some of the longer primary wing-feathers
became more or less white. When this occurred, Mr. Hewitt destroyed nearly
the whole of his stock and procured fresh eggs from wild nests; so that he
never bred the same family for more than five or six generations. His birds
continued to pair together, and never became polygamous like the common
domestic duck. I have given these details, because no other case, as far as
I know, has been so carefully recorded by a competent observer of the
progress of change in wild birds reared for several generations in a
domestic condition.
From these considerations there can hardly be a doubt that the wild duck is
the parent of the common domestic kind; nor need we look to other species
for the parentage of the more distinct breeds, namely, Penguin, Call, Hook-
billed, Tufted, and Labrador ducks. I will not repeat the arguments used in
the previous chapters on the improbability of man having in ancient times
domesticated several species since become unknown or extinct, though ducks
are not readily exterminated in the wild state;--on some of the supposed
parent-species having had abnormal characters in comparison with all the
other species of the genus, as with Hook-billed and Penguin ducks;--on all
the breeds, as far as is known being fertile together (8/10. I have met
with several statements on the fertility of the several breeds when
crossed. Mr. Yarrell assured me that Call and common ducks are perfectly
fertile together. I crossed Hook-billed and common ducks, and a Penguin and
Labrador, and the crossed Ducks were quite fertile, though they were not
bred inter se, so that the experiment was not fully tried. Some half-bred
Penguins and Labradors were again crossed with Penguins, and subsequently
bred by me inter se, and they were extremely fertile.);--on all the breeds
having the same general disposition, instinct, etc. But one fact bearing on
this question may be noticed: in the great duck family, one species alone,
namely, the male of A. boschas, has its four middle tail-feathers curled
upwardly; now in every one of the above-named domestic breeds these curled
feathers exist, and on the supposition that they are descended from
distinct species, we must assume that man formerly hit upon species all of
which had this now unique character. Moreover, sub-varieties of each breed
are coloured almost exactly like the wild duck, as I have seen with the
largest and smallest breeds, namely Rouens and Call ducks, and, as Mr.
Brent states (8/11. 'Poultry Chronicle' 1855 volume 3 page 512.), is the
case with Hook-billed ducks. This gentleman, as he informs me, crossed a
white Aylesbury drake and a black Labrador duck, and some of the ducklings
as they grew up assumed the plumage of the wild duck.
With respect to Penguins, I have not seen many specimens, and none were
coloured precisely like the wild duck; but Sir James Brooke sent me three
skins from Lombok and Bali, in the Malayan archipelago; the two females
were paler and more rufous than the wild duck, and the drake differed in
having the whole under and upper surface (excepting the neck, tail-coverts,
tail, and wings) silver-grey, finely pencilled with dark lines, closely
like certain parts of the plumage of the wild mallard. But I found this
drake to be identical in every feather with a variety of the common breed
procured from a farm-yard in Kent, and I have occasionally elsewhere seen
similar specimens. The occurrence of a duck bred under so peculiar a
climate as that of the Malayan archipelago, where the wild species does not
exist, with exactly the same plumage as may occasionally be seen in our
farm-yards, is a fact worth notice. Nevertheless the climate of the Malayan
archipelago apparently tends to cause the duck to vary much, for Zollinger
(8/12. 'Journal of the Indian Archipelago' volume 5 page 334.), speaking of
the Penguin breed, says that in Lombok "there is an unusual and very
wonderful variety of ducks." One Penguin drake which I kept alive differed
from those of which the skins were sent me from Lombok, in having its
breast and back partially coloured with chestnut-brown, thus more closely
resembling the Mallard.
From these several facts, more especially from the drakes of all the breeds
having curled tail-feathers, and from certain sub-varieties in each breed
occasionally resembling in general plumage the wild duck, we may conclude
with confidence that all the breeds are descended from A. boschas.
[I will now notice some of the peculiarities characteristic of the several
breeds. The eggs vary in colour; some common ducks laying pale-greenish and
others quite white eggs. The eggs which are first laid during each season
by the black Labrador duck, are tinted black, as if rubbed with ink. A good
observer assured me that one year his ducks of this breed laid almost
perfectly white eggs. Another curious case shows what singular variations
sometimes occur and are inherited; Mr. Hansell (8/13. 'The Zoologist'
volumes 7, 8 1849-1850 page 2353.) relates that he had a common duck which
always laid eggs with the yolk of a dark-brown colour like melted glue; and
the young ducks, hatched from these eggs, laid the same kind of eggs, so
that the breed had to be destroyed.
(FIGURE 39. SKULLS, viewed laterally, reduced to two-thirds of the natural
size. A. Wild Duck. B. Hook-billed Duck.)
The Hook-billed duck is highly remarkable (see figure 39, of skull); and
its peculiar beak has been inherited at least since the year 1676. This
structure is evidently analogous with that described in the Bagadotten
carrier pigeon. Mr. Brent (8/14. 'Poultry Chronicle' 1855 volume 3 page
512.) says that, when Hook-billed ducks are crossed with common ducks,
"many young ones are produced with the upper mandible shorter than the
lower, which not unfrequently causes the death of the bird." With ducks a
tuft of feathers on the head is by no means a rare occurrence; namely, in
the True-tufted breed, the Hook-billed, the common farm-yard kind, and in a
duck having no other peculiarity which was sent to me from the Malayan
archipelago. The tuft is only so far interesting as it affects the skull,
which is thus rendered slightly more globular, and is perforated by
numerous apertures. Call ducks are remarkable from their extraordinary
loquacity: the drake only hisses like common drakes; nevertheless, when
paired with the common duck, he transmits to his female offspring a strong
quacking tendency. This loquacity seems at first a surprising character to
have been acquired under domestication. But the voice varies in the
different breeds; Mr. Brent (8/15. 'Poultry Chronicle' volume 3 1855 page
312. With respect to Rouens see ditto volume 1 1854 page 167.) says that
Hook-billed ducks are very loquacious, and that Rouens utter a "dull, loud,
and monotonous cry, easily distinguishable by an experienced ear." As the
loquacity of the Call duck is highly serviceable, these birds being used in
decoys, this quality may have been increased by selection. For instance,
Colonel Hawker says, if young wild ducks cannot be got for a decoy, "by way
of make-shift, SELECT tame birds which are the most clamorous, even if
their colour should not be like that of wild ones." (8/16. Col. Hawker
'Instructions to young Sportsmen' quoted by Mr. Dixon in his 'Ornamental
Poultry' page 125.) It has been erroneously asserted that Call ducks hatch
their eggs in less time than common ducks. (8/17. 'Cottage Gardener' April
9, 1861.)
The Penguin duck is the most remarkable of all the breeds; the thin neck
and body are carried erect; the wings are small; the tail is upturned; and
the thigh-bones and metatarsi are considerably lengthened in proportion
with the same bones in the wild duck. In five specimens examined by me
there were only eighteen tail-feathers instead of twenty as in the wild
duck; but I have also found only eighteen and nineteen tail-feathers in two
Labrador ducks. On the middle toe, in three specimens, there were twenty-
seven or twenty-eight scutellae, whereas in two wild ducks there were
thirty-one and thirty-two. The Penguin when crossed transmits with much
power its peculiar form of body and gait to its offspring; this was
manifest with some hybrids raised in the Zoological Gardens between one of
these birds and the Egyptian goose (Anser aegyptiacus) (8/18. These hybrids
have been described by M. Selys-Longchamps in the 'Bulletins (tome 12 No
10) Acad. Roy. de Bruxelles.'), and likewise with some mongrels which I
raised between the Penguin and Labrador duck. I am not much surprised that
some writers should maintain that this breed must be descended from an
unknown and distinct species; but from the reasons already assigned, it
seems to me far more probable that it is the descendant, much modified by
domestication under an unnatural climate, of Anas boschas.
OSTEOLOGICAL CHARACTERS.
The skulls of the several breeds differ from each other and from the skull
of the wild duck in very little except in the proportional length and
curvature of the premaxillaries. These latter bones in the Call duck are
short, and a line drawn from their extremities to the summit of the skull
is nearly straight, instead of being concave as in the common duck; so that
the skull resembles that of a small goose. In the Hook-billed duck (figure
39), these same bones as well as the lower jaw curve downwards in a most
remarkable manner, as represented. In the Labrador duck the premaxillaries
are rather broader than in the wild duck; and in two skulls of this breed
the vertical ridges on each side of the supra-occipital bone are very
prominent. In the Penguin the premaxillaries are relatively shorter than in
the wild duck; and the inferior points of the paramastoids more prominent.
In a Dutch tufted duck, the skull under the enormous tuft was slightly more
globular and was perforated by two large apertures; in this skull the
lachrymal bones were produced much further backwards, so as to have a
different shape and nearly to touch the post. lat. processes of the frontal
bones, thus almost completing the bony orbit of the eye. As the quadrate
and pterygoid bones are of such complex shape and stand in relation with so
many other bones, I carefully compared them in all the principal breeds;
but excepting in size they presented no difference.
(FIGURE 40.-CERVICAL VERTEBRA, of natural size. A. Eighth cervical vertebra
of Wild Duck viewed on haemal surface. B. Eighth cervical vertebra of Call
Duck, viewed as above. C. Twelfth cervical vertebra of Wild Duck viewed
laterally. D. Twelfth cervical vertebra of Aylesbury Duck, viewed
laterally.)
VERTEBRAE AND RIBS.
In one skeleton of the Labrador duck there were the usual fifteen cervical
vertebrae and the usual nine dorsal vertebrae bearing ribs; in the other
skeleton there were fifteen cervical and ten dorsal vertebrae with ribs;
nor, as far as could be judged, was this owing merely to a rib having been
developed on the first lumbar vertebra; for in both skeletons the lumbar
vertebrae agreed perfectly in number, shape, and size with those of the
wild duck. In two skeletons of the Call duck there were fifteen cervical
and nine dorsal vertebrae; in a third skeleton small ribs were attached to
the so-called fifteenth cervical vertebra, making ten pairs of ribs; but
these ten ribs do not correspond, or arise from the same vertebra, with the
ten in the above-mentioned Labrador duck. In the Call duck, which had small
ribs attached to the fifteenth cervical vertebra, the haemal spines of the
thirteenth and fourteenth (cervical) and of the seventeenth (dorsal)
vertebrae corresponded with the spines on the fourteenth, fifteenth, and
eighteenth vertebrae of the wild duck: so that each of these vertebrae had
acquired a structure proper to one posterior to it in position. In the
eighth cervical vertebra of this same Call duck (figure 40, B), the two
branches of the haemal spine stand much closer together than in the wild
duck (A), and the descending haemal processes are much shortened. In the
Penguin duck the neck from its thinness and erectness falsely appears (as
ascertained by measurement) to be much elongated, but the cervical and
dorsal vertebrae present no difference; the posterior dorsal vertebrae,
however, are more completely anchylosed to the pelvis than in the wild
duck. The Aylesbury duck has fifteen cervical and ten dorsal vertebrae
furnished with ribs, but the same number of lumbar, sacral, and caudal
vertebrae, as far as could be traced, as in the wild duck. The cervical
vertebrae in this same duck (figure 40, D) were much broader and thicker
relatively to their length than in the wild (C); so much so, that I have
thought it worth while to give a sketch of the twelfth cervical vertebra in
these two birds. From the foregoing statements we see that the fifteenth
cervical vertebra occasionally becomes modified into a dorsal vertebra, and
when this occurs all the adjoining vertebrae are modified. We also see that
an additional dorsal vertebra bearing a rib is occasionally developed, the
number of the cervical and lumbar vertebrae apparently remaining the same
as usual.
I examined the bony enlargement of the trachea in the males of the Penguin,
Call, Hook-billed, Labrador, and Aylesbury breeds; and in all it was
identical in shape.
The PELVIS is remarkably uniform; but in the skeleton of the Hook-billed
duck the anterior part is much bowed inwards; in the Aylesbury and some
other breeds the ischiadic foramen is less elongated. In the sternum,
furculum, coracoids, and scapulae, the differences are so slight and so
variable as not to be worth notice, except that in two skeletons of the
Penguin duck the terminal portion of the scapula was much attenuated.
In the bones of the leg and wing no modification in shape could be
observed. But in the Penguin and Hook-billed ducks, the terminal phalanges
of the wing are a little shortened. In the former, the femur, and
metatarsus (but not the tibia) are considerably lengthened, relatively to
the same bones in the wild duck, and to the wing-bones in both birds. This
elongation of the leg-bones could be seen whilst the bird was alive, and is
no doubt connected with its peculiar upright manner of walking. In a large
Aylesbury duck, on the other hand, the tibia was the only bone of the leg
which relatively to the other bones was slightly lengthened.
ON THE EFFECTS OF THE INCREASED AND DECREASED USE OF THE LIMBS.
In all the breeds the bones of the wing (measured separately after having
been cleaned) relatively to those of the leg have become slightly
shortened, in comparison with the same bones in the wild duck, as may be
seen in Table 8.I.
TABLE 8.I.a.
COLUMN 1. Length of Femur, Tibia, and Metatarsus together (inches).
COLUMN 2. Length of Humerus, Radius, and Metacarpus together (inches).
COLUMN 3. Or as (ratio).
Name of Breed. 1. 2. 3.
Wild mallard. 7.14 9.28 100:129
Aylesbury. 8.64 10.43 100:120
Tufted (Dutch). 8.25 9.83 100:119
Penguin. 7.12 8.78 100:123
Call. 6.20 7.77 100:125
TABLE 8.I.b.
COLUMN 1. Length of Femur, Tibia, and Metatarsus together (inches).
COLUMN 2. Length of all the bones of the wing (inches).
COLUMN 3. Or as (ratio).
Name of Breed. 1. 2. 3.
Wild duck (another specimen). 6.85 10.07 100:147
Common domestic duck. 8.15 11.26 100:138
In table 8.I we see, by comparison with the wild duck, that the reduction
in the length of the bones of the wing, relatively to those of the legs,
though slight, is universal. The reduction is least in the Call duck, which
has the power and the habit of frequently flying.
In weight there is a greater relative difference between the bones of the
leg and wing, as may be seen in Table 8.II:
TABLE 8.II.a.
COLUMN 1. Weight of Femur, Tibia, and Metatarsus (grains).
COLUMN 2. Weight of Humerus, Radius, and Metacarpus (grains).
COLUMN 3. Or as (ratio).
Name of Breed. 1. 2. 3.
Wild mallard. 54 97 100:179
Aylesbury. 164 204 100:124
Hooked-bill. 107 160 100:149
Tufted (Dutch). 111 148 100:133
Penguin. 75 90.5 100:120
Labrador. 141 165 100:117
Call. 57 93 100:163
TABLE 8.II.b.
COLUMN 1. Weight of all the Bones of the Leg and Foot (grains).
COLUMN 2. Weight of all the Bones of the Wing (grains).
COLUMN 3. Or as (ratio).
Name of Breed. 1. 2. 3.
Wild (another specimen). 66 115 100:173
Common domestic duck. 127 158 100:124
In these domesticated birds, the considerably lessened weight of the bones
of the wing (i.e. on an average, twenty-five per cent of their proper
proportional weight), as well as their slightly lessened length, relatively
to the leg-bones, might follow, not from any actual decrease in the wing-
bones, but from the increased weight and length of the bones of the legs.
TABLE 8.III.a.
COLUMN 1. Weight of entire Skeleton (grains). (N.B. One Metatarsus and Foot
was removed from each skeleton, as it had been accidentally lost in two
cases.)
COLUMN 2. Weight of Femur, Tibia, and Metatarsus (grains).
COLUMN 3. Or as (ratio).
Name of Breed. 1. 2. 3.
Wild mallard. 839 54 1000:64
Aylesbury. 1925 164 1000:85
Tufted (Dutch). 1404 111 1000:79
Penguin. 871 75 1000:86
Call (from Mr. Fox). 717 57 1000:79
TABLE 8.III.b.
COLUMN 1. Weight of entire Skeleton (grains). (N.B. One Metatarsus and Foot
was removed from each skeleton, as it had been accidentally lost in two
cases.)
COLUMN 2. Weight of Humerus, Radius and Metacarpus (grains).
COLUMN 3. Or as (ratio).
Name of Breed. 1. 2. 3.
Wild mallard. 839 97 1000:115
Aylesbury. 1925 204 1000:105
Tufted (Dutch). 1404 148 1000:105
Penguin. 871 90 1000:103
Call (from Mr. Baker). 914 100 1000:109
Call (from Mr. Fox). 717 92 1000:129
Table 8.III.a shows that the leg-bones relatively to the weight of the
entire skeleton have really increased in weight; but Table 8.III.b shows
that according to the same standard the wing-bones have also really
decreased in weight; so that the relative disproportion shown in the
foregoing tables between the wing and leg-bones, in comparison with those
of the wild duck, is partly due to the increase in weight and length of the
leg-bones, and partly to the decrease in weight and length of the wing-
bones.
With respect to Tables 8.III.a and b, I may first state that I tested them
by taking another skeleton of a wild duck and of a common domestic duck,
and by comparing the weight of ALL the bones of the leg with ALL those of
the wings, and the result was the same. In the first of these tables we see
that the leg-bones in each case have increased in actual weight. It might
have been expected that, with the increased or decreased weight of the
entire skeleton, the leg-bones would have become proportionally heavier or
lighter; but their greater weight in all the breeds relatively to the other
bones can be accounted for only by these domestic birds having used their
legs in walking and standing much more than the wild, for they never fly,
and the more artificial breeds rarely swim. In the second table we see,
with the exception of one case, a plain reduction in the weight of the
bones of the wing, and this no doubt has resulted from their lessened use.
The one exceptional case, namely, in one of the Call ducks, is in truth no
exception, for this bird was constantly in the habit of flying about; and I
have seen it day after day rise from my grounds, and fly for a long time in
circles of more than a mile in diameter. In this Call duck there is not
only no decrease, but an actual increase in the weight of the wing-bones
relatively to those of the wild-duck; and this probably is consequent on
the remarkable lightness and thinness of all the bones of the skeleton.
Lastly, I weighed the furculum, coracoids, and scapula of a wild duck and
of a common domestic duck, and I found that their weight, relatively to
that of the whole skeleton, was as one hundred in the former to eighty-nine
in the latter; this shows that these bones in the domestic duck have been
reduced eleven per cent of their due proportional weight. The prominence of
the crest of the sternum, relatively to its length, is also much reduced in
all the domestic breeds. These changes have evidently been caused by the
lessened use of the wings.]
It is well known that several birds, belonging to different Orders, and
inhabiting oceanic islands, have their wings greatly reduced in size and
are incapable of flight. I suggested in my 'Origin of Species' that, as
these birds are not persecuted by any enemies, the reduction of their wings
had probably been caused by gradual disuse. Hence, during the earlier
stages of the process of reduction, such birds would probably have
resembled our domesticated ducks in the state of their organs of flight.
This is the case with the water-hen (Gallinula nesiotis) of Tristan
d'Acunha, which "can flutter a little, but obviously uses its legs, and not
its wings, as a mode of escape." Now Mr. Sclater (8/19. 'Proc. Zoolog.
Soc.' 1861 page 261.) finds in this bird that the wings, sternum, and
coracoids are all reduced in length, and the crest of the sternum in depth,
in comparison with the same bones in the European water-hen (G. chloropus).
On the other hand, the thigh-bones and pelvis are increased in length, the
former by four lines, relatively to the same bones in the common water-hen.
Hence in the skeleton of this natural species nearly the same changes have
occurred, only carried a little further, as with our domestic ducks, and in
this latter case I presume no one will dispute that they have resulted from
the lessened use of the wings and the increased use of the legs.
THE GOOSE.
This bird deserves some notice, as hardly any other anciently domesticated
bird or quadruped has varied so little. That geese were anciently
domesticated we know from certain verses in Homer; and from these birds
having been kept (388 B.C.) in the Capitol at Rome as sacred to Juno, which
sacredness implies great antiquity. (8/20. 'Ceylon' by Sir J.E. Tennent
1859 volume 1 page 485; also J. Crawfurd on the 'Relation of Domest.
Animals to Civilisation' read before Brit. Assoc. 1860. See also
'Ornamental Poultry' by Rev. E.S. Dixon 1848 page 132. The goose figured on
the Egyptian monuments seems to have been the Red goose of Egypt.) That the
goose has varied in some degree, we may infer from naturalists not being
unanimous with respect to its wild parent-form; though the difficulty is
chiefly due to the existence of three or four closely allied wild European
species. (8/21. Macgillivray's 'British Birds' volume 4 page 593.) A large
majority of capable judges are convinced that our geese are descended from
the wild Grey-leg goose (Anser ferus); the young of which can easily be
tamed. (8/22. Mr. A. Strickland, 'Annals and Mag. of Nat. Hist.' 3rd series
volume 3 1859 page 122, reared some young wild geese, and found them in
habits and in all characters identical with the domestic goose.) This
species, when crossed with the domestic goose, produced in the Zoological
Gardens, as I was assured in 1849, perfectly fertile offspring. (8/23. See
also Hunter 'Essays' edited by Owen volume 2 page 322.) Yarrell (8/24.
Yarrell's 'British Birds' volume 3 page 142.) has observed that the lower
part of the trachea of the domestic goose is sometimes flattened, and that
a ring of white feathers sometimes surrounds the base of the beak. These
characters seem at first sight good indications of a cross at some former
period with the white-fronted goose (A. albifrons); but the white ring is
variable in this latter species, and we must not overlook the law of
analogous variation; that is, of one species assuming some of the
characters of allied species.
As the goose has proved so little flexible in its organisation under long-
continued domestication, the amount of variation which it has undergone may
be worth giving. It has increased in size and in productiveness (8/25. L.
Lloyd 'Scandinavian Adventures' 1854 volume 2 page 413, says that the wild
goose lays from five to eight eggs, which is a much fewer number than that
laid by our domestic goose.); and varies from white to a dusky colour.
Several observers (8/26. The Rev. L. Jenyns (Blomefield) seems first to
have made this observation in his 'British Animals.' See also Yarrell, and
Dixon in his 'Ornamental Poultry' (page 139), and 'Gardener's Chronicle'
1857 page 45.) have stated that the gander is more frequently white than
the goose, and that when old it almost invariably becomes white; but this
is not the case with the parent-form, the A. ferus. Here, again, the law of
analogous variation may have come into play, as the almost snow-white male
of the Rock goose (Bernicla antarctica) standing on the sea-shore by his
dusky partner is a sight well known to those who have traversed the sounds
of Tierra del Fuego and the Falkland Islands. Some geese have top-knots;
and the skull beneath, as before stated, is perforated. A sub-breed has
lately been formed with the feathers reversed at the back of the head and
neck. (8/27. Mr. Bartlet exhibited the head and neck of a bird thus
characterised before the Zoological Soc. February 1860.) The beak varies a
little in size, and is of a yellower tint than in the wild species; but its
colour and that of the legs are both slightly variable. (8/28. W. Thompson
'Natural Hist. of Ireland' 1851 volume 3 page 31. The Rev. E.S. Dixon gave
me some information on the varying colour of the beak and legs.) This
latter fact deserves attention, because the colour of the legs and beak is
highly serviceable in discriminating the several closely allied wild forms.
(8/29. Mr. A. Strickland in 'Annals and Mag. of Nat. Hist.' 3rd series
volume 3 1859 page 122.) At our Shows two breeds are exhibited; viz., the
Embden and Toulouse; but they differ in nothing except colour. (8/30.
'Poultry Chronicle' volume 1 1854 page 498; volume 3 page 210.) Recently a
smaller and singular variety has been imported from Sebastopol (8/31. 'The
Cottage Gardener' September 4, 1860 page 348.), with the scapular feathers
(as I hear from Mr. Tegetmeier, who sent me specimens) greatly elongated,
curled, and even spirally twisted. The margins of these feathers are
rendered plumose by the divergence of the barbs and barbules, so that they
resemble in some degree those on the back of the black Australian swan.
These feathers are likewise remarkable from the central shaft, which is
excessively thin and transparent, being split into fine filaments, which,
after running for a space free, sometimes coalesce again. It is a curious
fact that these filaments are regularly clothed on each side with fine down
or barbules, precisely like those on the proper barbs of the feather. This
structure of the feathers is transmitted to half-bred birds. In Gallus
sonneratii the barbs and barbules blend together, and form thin horny
plates of the same nature with the shaft: in this variety of the goose, the
shaft divides into filaments which acquire barbules, and thus resemble true
barbs.
Although the domestic goose certainly differs somewhat from any known wild
species, yet the amount of variation which it has undergone, as compared
with that of most domesticated animals, is singularly small. This fact can
be partially accounted for by selection not having come largely into play.
Birds of all kinds which present many distinct races are valued as pets or
ornaments; no one makes a pet of the goose; the name, indeed, in more
languages than one, is a term of reproach. The goose is valued for its size
and flavour, for the whiteness of its feathers which adds to their value,
and for its prolificness and tameness. In all these points the goose
differs from the wild parent-form; and these are the points which have been
selected. Even in ancient times the Roman gourmands valued the liver of the
WHITE goose; and Pierre Belon (8/32. 'L'Hist. de la Nature des Oiseaux' par
P. Belon 1555 page 156. With respect to the livers of white geese being
preferred by the Romans see Isid. Geoffroy St.-Hilaire 'Hist. Nat. Gen.'
tome 3 page 58.) in 1555 speaks of two varieties, one of which was larger,
more fecund, and of a better colour than the other; and he expressly states
that good managers attended to the colour of their goslings, so that they
might know which to preserve and select for breeding.
THE PEACOCK.
This is another bird which has hardly varied under domestication, except in
sometimes being white or piebald. Mr. Waterhouse carefully compared, as he
informs me, skins of the wild Indian and domestic bird, and they were
identical in every respect, except that the plumage of the latter was
perhaps rather thicker. Whether our birds are descended from those
introduced into Europe in the time of Alexander, or have been subsequently
imported, is doubtful. They do not breed very freely with us, and are
seldom kept in large numbers,--circumstances which would greatly interfere
with the gradual selection and formation of new breeds.
There is one strange fact with respect to the peacock, namely, the
occasional appearance in England of the "japanned" or "black-shouldered"
kind. This form has lately been named on the high authority of Mr. Sclater
as a distinct species, viz. Pavo nigripennis, which he believes will
hereafter be found wild in some country, but not in India, where it is
certainly unknown. The males of these japanned birds differ conspicuously
from the common peacock in the colour of their secondary wing-feathers,
scapulars, wing-coverts, and thighs, and are I think more beautiful; they
are rather smaller than the common sort, and are always beaten by them in
their battles, as I hear from the Hon. A.S.G. Canning. The females are much
paler coloured than those of the common kind. Both sexes, as Mr. Canning
informs me, are white when they leave the egg, and they differ from the
young of the white variety only in having a peculiar pinkish tinge on their
wings. These japanned birds, though appearing suddenly in flocks of the
common kind, propagate their kind quite truly. Although they do not
resemble the hybrids which have been raised between P. cristatus and
muticus, nevertheless they are in some respects intermediate in character
between these two species; and this fact favours, as Mr. Sclater believes,
the view that they form a distinct and natural species. (8/33. Mr. Sclater
on the black-shouldered peacock of Latham 'Proc. Zoolog. Soc.' April 24,
1860. Mr. Swinhoe at one time believed, 'Ibis' July 1868, that this kind of
peafowl was found wild in Cochin China, but he has since informed me that
he feels very doubtful on this head.)
On the other hand, Sir H. Heron states (8/34. 'Proc. Zoolog. Soc.' April
14, 1835.) that this breed suddenly appeared within his memory in Lord
Brownlow's large stock of pied, white, and common peacocks. The same thing
occurred in Sir J. Trevelyan's flock composed entirely of the common kind,
and in Mr. Thornton's stock of common and pied peacocks. It is remarkable
that in these two latter instances the black-shouldered kind, though a
smaller and weaker bird, increased, "to the extinction of the previously
existing breed." I have also received through Mr. Sclater a statement from
Mr. Hudson Gurney that he reared many years ago a pair of black-shouldered
peacocks from the common kind; and another ornithologist, Prof. A. Newton,
states that, five or six years ago, a female bird, in all respects similar
to the female of the black-shouldered kind, was produced from a stock of
common peacocks in his possession, which during more than twenty years had
not been crossed with birds of any other strain. Mr. Jenner Weir informs me
that a peacock at Blackheath whilst young was white, but as it became older
gradually assumed the characters of the black-shouldered variety; both its
parents were common peacocks. Lastly, Mr. Canning has given a case of a
female of this same variety appearing in Ireland in a flock of the ordinary
kind. (8/35. 'The Field' May 6, 1871. I am much indebted to Mr. Canning for
information with respect to his birds.) Here, then, we have seven well
authenticated cases in Great Britain of japanned birds, having suddenly
appeared within recent times in flocks of the common peafowl. This variety
must also have formerly appeared in Europe, for Mr. Canning has seen an old
picture, and another is referred to in the 'Field,' with this variety
represented. These facts seem to me to indicate that the japanned peacock
is a strongly marked variety or "sport," which tends at all times and in
many places to reappear. This view is supported by the young being at first
white like the young of the white breed, which is undoubtedly a variation.
If, on the other hand, we believe the japanned peacock to be a distinct
species, we must suppose that in all the above cases the common breed had
at some former period been crossed by it, but had lost every trace of the
cross; yet that the offspring of these birds suddenly and completely
reacquired through reversion the characters of P. nigripennis. I have heard
of no other such case in the animal or vegetable kingdom. To perceive the
full improbability of such an occurrence, we may suppose that a breed of
dogs had been crossed at some former period with a wolf, but had lost every
trace of the wolf-like character, yet that the breed gave birth in seven
instances in the same country, within no great length of time, to a wolf
perfect in every character; and we must further suppose that in two of the
cases, the newly produced wolves afterwards spontaneously increased to such
an extent as to lead to the extinction of the parent breed of dogs. So
remarkable a bird as the P. nigripennis, when first imported, would have
realised a large price; it is therefore improbable that it should have been
silently introduced and its history subsequently lost. On the whole the
evidence seems to me, as it did to Sir R. Heron, to be decisive in favour
of the japanned or black-shouldered breed being a variation, induced by
some unknown cause. On this view, the case is the most remarkable one ever
recorded of the abrupt appearance of a new form, which so closely resembles
a true species that it has deceived one of the most experienced of living
ornithologists.
THE TURKEY.
It seems fairly well established by Mr. Gould (8/36. 'Proc. Zoolog. Soc.'
April 8, 1856 page 61. Prof. Baird believes (as quoted in Tegetmeier
'Poultry Book' 1866 page 269) that our turkeys are descended from a West
Indian species now extinct. But besides the improbability of a bird having
long ago become extinct in these large and luxuriant islands, it appears
(as we shall presently see) that the turkey degenerates in India, and this
fact indicates that it was not aboriginally an inhabitant of the lowlands
of the tropics.), that the turkey, in accordance with the history of its
first introduction, is descended from a wild Mexican form, which had been
domesticated by the natives before the discovery of America, and which is
now generally ranked as a local race, and not as a distinct species.
However this may be, the case deserves notice because in the United States
wild male turkeys sometimes court the domestic hens, which are descended
from the Mexican form, "and are generally received by them with great
pleasure." (8/37. Audubon 'Ornithological Biography' volume 1 1831 pages 4-
13; and 'Naturalist's Library' volume 14 'Birds' page 138.) Several
accounts have likewise been published of young birds, reared in the United
States from the eggs of the wild species, crossing and commingling with the
common breed. In England, also, this same species has been kept in several
parks; from two of which the Rev. W.D. Fox procured birds, and they crossed
freely with the common domestic kind, and during many years afterwards, as
he informs me, the turkeys in his neighbourhood clearly showed traces of
their crossed parentage. We here have an instance of a domestic race being
modified by a cross with a distinct wild race or species. F. Michaux (8/38.
F. Michaux 'Travels in N. America' 1802 English translation page 217.)
suspected in 1802 that the common domestic turkey was not descended from
the United States species alone, but likewise from a southern form, and he
went so far as to believe that English and French turkeys differed from
having different proportions of the blood of the two parent-forms.
English turkeys are smaller than either wild form. They have not varied in
any great degree; but there are some breeds which can be distinguished as
Norfolks, Suffolks, Whites, and Copper-coloured (or Cambridge), all of
which, if precluded from crossing with other breeds propagate their kind
truly. Of these kinds, the most distinct is the small, hardy, dull-black
Norfolk turkey, of which the chickens are black, occasionally with white
patches about the head. The other breeds scarcely differ except in colour,
and their chickens are generally mottled all over with brownish-grey.
(8/39. 'Ornamental Poetry' by the Rev. E.S. Dixon 1848 page 34.) The
inferior tail-coverts vary in number, and according to a German
superstition the hen lays as many eggs as the cock has feathers of this
kind. (8/40. Bechstein 'Naturgesch. Deutschlands' b. 3 1793 s. 309.) Albin
in 1738, and Temminck within a much later period, describe a beautiful
breed, dusky-yellowish, brown above and white beneath, with a large top-
knot of soft plumose feather. The spurs of the male were rudimentary. This
breed has been for a long time extinct in Europe; but a living specimen has
lately been imported from the east coast of Africa, which still retains the
top-knot and the same general colouring and rudimentary spurs. (8/41. Mr.
Bartlett in 'Land and Water' October 31, 1868 page 233; and Mr. Tegetmeier
in the 'Field' July 17, 1869 page 46.) Mr. Wilmot has described (8/42.
'Gardener's Chronicle' 1852 page 699.) a white turkey-cock having a crest
formed of "feathers about four inches long, with bare quills, and a tuft of
soft white down growing at the end." Many of the young birds inherited this
kind of crest, but afterwards it fell off or was pecked out by the other
birds. This is an interesting case, as with care a new breed might probably
have been formed; and a top-knot of this nature would have been to a
certain extent analogous to that borne by the males in several allied
genera, such as Euplocomus, Lophophorus, and Pavo.
Wild turkeys, believed in every instance to have been imported from the
United States, have been kept in the parks of Lords Powis, Leicester, Hill,
and Derby. The Rev. W.D. Fox procured birds from the two first-named parks,
and he informs me that they certainly differed a little from each other in
the shape of their bodies and in the barred plumage on their wings. These
birds likewise differed from Lord Hill's stock. Some of the latter kept at
Oulton by Sir P. Egerton, though precluded from crossing with common
turkeys, occasionally produced much paler-coloured birds, and one that was
almost white, but not an albino. These half-wild turkeys, in thus differing
slightly from each other, present an analogous case with the wild cattle
kept in the several British parks. We must suppose that such differences
have resulted from the prevention of free intercrossing between birds
ranging over a wide area, and from the changed conditions to which they
have been exposed in England. In India the climate has apparently wrought a
still greater change in the turkey, for it is described by Mr. Blyth (8/43.
E. Blyth 'Annals and Mag. of Nat. Hist.' 1847 volume 20 page 391.) as being
much degenerated in size, "utterly incapable of rising on the wing," of a
black colour, and "with the long pendulous appendages over the beak
enormously developed."
THE GUINEA FOWL.
The domesticated Guinea fowl is now believed by some naturalists to be
descended from the Numida ptilorhynca, which inhabits very hot, and, in
parts, extremely arid districts in Eastern Africa; consequently it has been
exposed in this country to extremely different conditions of life.
Nevertheless it has hardly varied at all, except in the plumage being
either paler or darker-coloured. It is a singular fact that this bird
varies more in colour in the West Indies and on the Spanish Main, under a
hot though humid climate, than in Europe. (8/44. Roulin makes this remark
in 'Mem. de divers Savans, 1'Acad. des Sciences' tome 6 1835 page 349. Mr.
Hill of Spanish Town in a letter to me describes five varieties of the
Guinea fowl in Jamaica. I have seen singular pale-coloured varieties
imported from Barbadoes and Demerara.) The Guinea fowl has become
thoroughly feral in Jamaica and in St. Domingo (8/45. For St. Domingo see
M. A. Salle, in 'Proc. Zoolog. Soc.' 1857 page 236. Mr. Hill remarks to me,
in his letter, on the colour of the legs of the feral birds in Jamaica.),
and has diminished in size; the legs are black, whereas the legs of the
aboriginal African bird are said to be grey. This small change is worth
notice on account of the often-repeated statement that all feral animals
invariably revert in every character to their original type.
THE CANARY BIRD.
As this bird has been recently domesticated, namely, within the last 350
years, its variability deserves notice. It has been crossed with nine or
ten other species of Fringillidae, and some of the hybrids are almost
completely fertile; but we have no evidence that any distinct breed has
originated from such crosses. Notwithstanding the modern domestication of
the canary, many varieties have been produced; even before the year 1718 a
list of twenty-seven varieties was published in France (8/46. Mr. B.P.
Brent 'The Canary, British Finches' etc. pages 21, 30.), and in 1779 a long
schedule of the desired qualities was printed by the London Canary Society,
so that methodical selection has been practised during a considerable
period. The greater number of the varieties differ only in colour and in
the markings of their plumage. Some breeds however, differ in shape, such
as the hooped or bowed canaries, and the Belgian canaries with their much
elongated bodies. Mr. Brent (8/47. 'Cottage Gardener' December 11, 1855
page 184: an account is here given of all the varieties. For many
measurements of the wild birds, see Mr. E. Vernon Harcourt ibid December
25, 1855 page 223.) measured one of the latter and found it eight inches in
length, whilst the wild canary is only five and a quarter inches long.
There are top-knotted canaries, and it is a singular fact that, if two top-
knotted birds are matched, the young, instead of having very fine top-
knots, are generally bald, or even have a wound on their heads. (8/48.
Bechstein 'Naturgesch. der Stubenvogel' 1840 s. 243; see s. 252 on the
inherited song of Canary-birds. With respect to their baldness see also W.
Kidd 'Treatise on Song-Birds.') It would appear as if the top-knot were due
to some morbid condition, which is increased to an injurious degree when
two birds in this state are paired. There is a feather-footed breed, and
another with a kind of frill running down the breast. One other character
deserves notice from being confined to one period of life, and from being
strictly inherited at the same period; namely, the wing and tail feathers
in prize canaries being black, "but this colour is retained only until the
first moult; once moulted, the peculiarity ceases." (8/49. W. Kidd
'Treatise on Song-Birds' page 18.) Canaries differ much in disposition and
character, and in some small degree in song. They produce eggs three or
four times during the year.
GOLD-FISH.
Besides mammals and birds, only a few animals belonging to the other great
classes have been domesticated; but to show that it is an almost universal
law that animals, when removed from their natural conditions of life, vary,
and that races can be formed when selection is applied, it is necessary to
say a few words on gold-fish, bees, and silk-moths.
Gold-fish (Cyprinus auratus) were introduced into Europe only two or three
centuries ago; but they have been kept in confinement from an ancient
period in China. Mr. Blyth (8/50. The 'Indian Field' 1858 page 255.)
suspects, from the analogous variation of other fishes, that golden-
coloured fish do not occur in a state of nature. These fishes frequently
live under the most unnatural conditions, and their variability in colour,
size, and in some important points of structure is very great. M. Sauvigny
has described and given coloured drawings of no less than eighty-nine
varieties. (8/51. Yarrell 'British Fishes' volume 1 page 319.) Many of the
varieties, however, such as triple tail-fins, etc., ought to be called
monstrosities; but it is difficult to draw any distinct line between a
variation and a monstrosity. As gold-fish are kept for ornament or
curiosity, and as "the Chinese are just the people to have secluded a
chance variety of any kind, and to have matched and paired from it" (8/52.
Mr. Blyth in the 'Indian Field' 1858 page 255.), it might have been
predicted that selection would have been largely practised in the formation
of new breeds; and this is the case. In an old Chinese work it is said that
fish with vermilion scales were first raised in confinement during the Sung
dynasty (which commenced A.D. 960), "and now they are cultivated in
families everywhere for the sake of ornament." In another and more ancient
work, it is said that "there is not a household where the gold-fish is not
cultivated, in RIVALRY as to its colour, and as a source of profit," etc.
(8/53. W.F. Mayers 'Chinese Notes and Queries' August 1868 page 123.)
Although many breeds exist, it is a singular fact that the variations are
often not inherited. Sir R. Heron (8/54. 'Proc. Zoolog. Soc.' May 25,
1842.) kept many of these fishes, and placed all the deformed ones, namely,
those destitute of dorsal fins and those furnished with a double anal fin,
or triple tail, in a pond by themselves; but they did "not produce a
greater proportion of deformed offspring than the perfect fishes."
Passing over an almost infinite diversity of colour, we meet with the most
extraordinary modifications of structure. Thus, out of about two dozen
specimens bought in London, Mr. Yarrell observed some with the dorsal fin
extending along more than half the length of the back: others with this fin
reduced to only five or six rays: and one with no dorsal fin. The anal fins
are sometimes double, and the tail is often triple. This latter deviation
of structure seems generally to occur "at the expense of the whole or part
of some other fin (8/55. Yarrell 'British Fishes' volume 1 page 319.); but
Bory de Saint-Vincent (8/56. 'Dict. Class. d'Hist. Nat.' tome 5 page 276.)
saw at Madrid gold-fish furnished with a dorsal fin and a triple tail. One
variety is characterised by a hump on its back near the head; and the Rev.
L. Jenyns (Blomefield) (8/57. 'Observations in Nat. Hist.' 1846 page 211.
Dr. Gray has described in 'Annals and Mag. of Nat. Hist.' 1860 page 151 a
nearly similar variety but destitute of a dorsal fin.) has described a most
singular variety, imported from China, almost globular in form like a
Diodon, with "the fleshy part of the tail as if entirely cut away? the
caudal fin being set on a little behind the dorsal and immediately above
the anal." In this fish the anal and caudal fins were double; the anal fin
being attached to the body in a vertical line: the eyes also were
enormously large and protuberant.
HIVE-BEES.
Bees have been domesticated from an ancient period; if indeed their state
can be considered one of domestication, for they search for their own food,
with the exception of a little generally given to them during the winter.
Their habitation is a hive instead of a hole in a tree. Bees, however, have
been transported into almost every quarter of the world, so that climate
ought to have produced whatever direct effect it is capable of producing.
It is frequently asserted that the bees in different parts of Great Britain
differ in size, colour, and temper; and Godron (8/58. 'De l'Espece' 1859
page 459. With respect to the bees of Burgundy see M. Gerard, art. 'Espece'
in 'Dict. Univers. d'Hist. Nat.') says that they are generally larger in
the south than in other parts of France; it has also been asserted that the
little brown bees of High Burgundy, when transported to La Bresse become
large and yellow in the second generation. But these statements require
confirmation. As far as size is concerned, it is known that bees produced
in very old combs are smaller, owing to the cells having become smaller
from the successive old cocoons. The best authorities (8/59. See a
discussion on this subject, in answer to a question of mine, in 'Journal of
Horticulture' 1862 pages 225-242; also Mr. Bevan Fox in ditto 1862 page
284) concur that, with the exception of the Ligurian race or species,
presently to be mentioned, distinct breeds do not exist in Britain or on
the Continent. There is, however, even in the same stock, some variability
in colour. Thus, Mr. Woodbury states (8/60. This excellent observer may be
implicitly trusted; see 'Journal of Horticulture' July 14, 1863 page 39.)
that he has several times seen queen bees of the common kind annulated with
yellow-like Ligurian queens, and the latter dark-coloured like common bees.
He has also observed variations in the colour of the drones, without any
corresponding difference in the queens or workers of the same hive. The
great apiarian, Dzierzon, in answer to my queries on this subject, says
(8/61. 'Journal of Horticulture' September 9, 1862 page 463; see also Herr
Kleine on same subject November 11 page 643, who sums up, that, though
there is some variability in colour, no constant or perceptible differences
can be detected in the bees of Germany.), that in Germany bees of some
stocks are decidedly dark, whilst others are remarkable for their yellow
colour. Bees also seem to differ in habits in different districts, for
Dzierzon adds, "If many stocks with their offspring are more inclined to
swarm, whilst others are richer in honey, so that some bee-keepers even
distinguish between swarming and honey-gathering bees, this is a habit
which has become second nature, caused by the customary mode of keeping the
bees and the pasturage of the district. For example, what a difference in
this respect one may perceive to exist between the bees of the Luneburg
heath and those of this country!"..."Removing an old queen and substituting
a young one of the current year is here an infallible mode of keeping the
strongest stock from swarming and preventing drone-breeding; whilst the
same means if adopted in Hanover would certainly be of no avail." I
procured a hive full of dead bees from Jamaica, where they have long been
naturalised, and, on carefully comparing them under the microscope with my
own bees, I could detect not a trace of difference.
This remarkable uniformity in the hive-bee, wherever kept, may probably be
accounted for by the great difficulty, or rather impossibility, of bringing
selection into play by pairing particular queens and drones, for these
insects unite only during flight. Nor is there any record, with a single
partial exception, of any person having separated and bred from a hive in
which the workers presented some appreciable difference. In order to form a
new breed, seclusion from other bees would, as we now know, be
indispensable; for since the introduction of the Ligurian bee into Germany
and England, it has been found that the drones wander at least two miles
from their own hives, and often cross with the queens of the common bee.
(8/62. Mr. Woodbury has published several such accounts in 'Journal of
Horticulture' 1861 and 1862.) The Ligurian bee, although perfectly fertile
when crossed with the common kind, is ranked by most naturalists as a
distinct species, whilst by others it is ranked as a variety: but this form
need not here be noticed, as there is no reason to believe that it is the
product of domestication. The Egyptian and some other bees are likewise
ranked by Dr. Gerstacker (8/63. 'Annals and Mag. of Nat. Hist.' 3rd series
volume 11 page 339.) but not by other highly competent judges, as
geographical races; he grounds his conclusion in chief part on the fact
that in certain districts, as in the Crimea and Rhodes, they vary so much
in colour, that the several geographical races can be closely connected by
intermediate forms.
I have alluded to a single instance of the separation and preservation of a
particular stock of bees. Mr. Lowe (8/64. 'The Cottage Gardener' May 1860
page 110; and ditto in 'Journal of Hort.' 1862 page 242.) procured some
bees from a cottager a few miles from Edinburgh, and perceived that they
differed from the common bee in the hairs on the head and thorax being
lighter coloured and more profuse in quantity. From the date of the
introduction of the Ligurian bee into Great Britain we may feel sure that
these bees had not been crossed with this form. Mr. Lowe propagated this
variety, but unfortunately did not separate the stock from his other bees,
and after three generations the new character was almost completely lost.
Nevertheless, as he adds, "a great number of the bees still retain traces,
though faint, of the original colony." This case shows us what could
probably be effected by careful and long-continued selection applied
exclusively to the workers, for, as we have seen, queens and drones cannot
be selected and paired.
SILK-MOTHS.
These insects are in several respects interesting to us, more especially
because they have varied largely at an early period of life, and the
variations have been inherited at corresponding periods. As the value of
the silk-moth depends entirely on the cocoon, every change in its structure
and qualities has been carefully attended to, and races differing much in
the cocoon, but hardly at all in the adult state, have been produced. With
the races of most other domestic animals, the young resemble each other
closely, whilst the adults differ much.
It would be useless, even if it were possible, to describe all the many
kinds of silkworms. Several distinct species exist in India and China which
produce useful silk, and some of these are capable of freely crossing with
the common silk-moth, as has been recently ascertained in France. Captain
Hutton (8/65. 'Transact. Entomolog. Soc.' 3rd series volume 3 pages 143-173
and pages 295-331.) states that throughout the world at least six species
have been domesticated; and he believes that the silk-moths reared in
Europe belong to two or three species. This, however, is not the opinion of
several capable judges who have particularly attended to the cultivation of
this insect in France; and hardly accords with some facts presently to be
given.
The common silk-moth (Bombyx mori) was brought to Constantinople in the
sixth century, whence it was carried into Italy, and in 1494 into France.
(8/66. Godron 'De l'Espece' 1859 tome 1 page 460. The antiquity of the
silkworm in China is given on the authority of Stanislas Julien.)
Everything has been favourable for the variation of this insect. It is
believed to have been domesticated in China as long ago as 2700 B.C. It has
been kept under unnatural and diversified conditions of life, and has been
transported into many countries. There is reason to believe that the nature
of the food given to the caterpillar influences to a certain extent the
character of the breed. (8/67. See the remarks of Prof. Westwood, Gen.
Hearsey and others at the meeting of the Entomolog. Soc. of London July
1861.) Disuse has apparently aided in checking the development of the
wings. But the most important element in the production of the many now
existing, much modified races, no doubt has been the close attention which
has long been applied in many countries to every promising variation. The
care taken in Europe in the selection of the best cocoons and moths for
breeding is notorious (8/68. See for instance M. A. de Quatrefages 'Etudes
sur les Maladies actuelles du Ver a Soie' 1859 page 101.), and the
production of eggs is followed as a distinct trade in parts of France. I
have made inquiries through Dr. Falconer, and am assured that in India the
natives are equally careful in the process of selection. In China the
production of eggs is confined to certain favourable districts, and the
raisers are precluded by law from producing silk, so that their whole
attention may be necessarily given up to this one object. (8/69. My
authorities for the statements will be given in the chapter on Selection.)
[The following details on the differences between the several breeds are
taken, when not stated to the contrary, from M. Robinet's excellent work
(8/70. 'Manuel de l'Educateur de Vers a Soie' 1848.), which bears every
sign of care and large experience. The EGGS in the different races vary in
colour, in shape (being round, elliptic or oval), and in size. The eggs
laid in June in the south of France, and in July in the central provinces,
do not hatch until the following spring; and it is in vain, says M.
Robinet, to expose them to a temperature gradually raised, in order that
the caterpillar may be quickly developed. Yet occasionally, without any
known cause, batches of eggs are produced, which immediately begin to
undergo the proper changes, and are hatched in from twenty to thirty days.
From these and some other analogous facts it may be concluded that the
Trevoltini silkworms of Italy, of which the caterpillars are hatched in
from fifteen to twenty days, do not necessarily form, as has been
maintained, a distinct species. Although the breeds which live in temperate
countries produce eggs which cannot be immediately hatched by artificial
heat, yet when they are removed to and reared in a hot country they
gradually acquire the character of quick development, as in the Trevoltini
races. (8/71. Robinet ibid pages 12, 318. I may add that the eggs of N.
American silkworms taken to the Sandwich Islands produced moths at very
irregular periods; and the moths thus raised yielded eggs which were even
worse in this respect. Some were hatched in ten days, and others not until
after the lapse of many months. No doubt a regular early character would
ultimately have been acquired. See review in 'Athenaeum' 1844 page 329 of
J. Jarves 'Scenes in the Sandwich Islands.')
CATERPILLARS.
These vary greatly in size and colour. The skin is generally white,
sometimes mottled with black or grey, and occasionally quite black. The
colour, however, as M. Robinet asserts, is not constant, even in perfectly
pure breeds; except in the race tigree, so called from being marked with
transverse black stripes. As the general colour of the caterpillar is not
correlated with that of the silk (8/72. 'The Art of rearing Silkworms'
translated from Count Dandolo 1825 page 23.), this character is disregarded
by cultivators, and has not been fixed by selection. Captain Hutton, in the
paper before referred to, has argued with much force that the dark tiger-
like marks, which so frequently appear during the later moults in the
caterpillars of various breeds, are due to reversion; for the caterpillars
of several allied wild species of Bombyx are marked and coloured in this
manner. He separated some caterpillars with the tiger-like marks, and in
the succeeding spring (pages 149, 298) nearly all the caterpillars reared
from them were dark-brindled, and the tints became still darker in the
third generation. The moths reared from these caterpillars (8/73.
'Transact. Ent. Soc.' ut supra pages 153, 308.) also became darker, and
resembled in colouring the wild B. huttoni. On this view of the tiger-like
marks being due to reversion, the persistency with which they are
transmitted is intelligible.
Several years ago Mrs. Whitby took great pains in breeding silkworms on a
large scale, and she informed me that some of her caterpillars had dark
eyebrows. This is probably the first step in reversion towards the tiger-
like marks, and I was curious to know whether so trifling a character would
be inherited. At my request she separated in 1848 twenty of these
caterpillars, and having kept the moths separate, bred from them. Of the
many caterpillars thus reared, "every one without exception had eyebrows,
some darker and more decidedly marked than the others, but ALL had eyebrows
more or less plainly visible." Black caterpillars occasionally appear
amongst those of the common kind, but in so variable a manner, that,
according to M. Robinet, the same race will one year exclusively produce
white caterpillars, and the next year many black ones; nevertheless, I have
been informed by M. A. Bossi of Geneva, that, if these black caterpillars
are separately bred from, they reproduce the same colour; but the cocoons
and moths reared from them do not present any difference.
The caterpillar in Europe ordinarily moults four times before passing into
the cocoon stage; but there are races "a trois mues," and the Trevoltini
race likewise moults only thrice. It might have been thought that so
important a physiological difference would not have arisen under
domestication; but M. Robinet (8/74. Robinet ibid page 317.) states that,
on the one hand, ordinary caterpillars occasionally spin their cocoons
after only three moults, and, on the other hand, "presque toutes les races
a trois mues, que nous avons experimentees, ont fait quatre mues a la
seconde ou a la troisieme annee, ce qui semble prouver qu'il a suffi de les
placer dans des conditions favorables pour leur rendre une faculte qu'elles
avaient perdue sous des influences moins favorables."
COCOONS.
The caterpillar in changing into the cocoon loses about 50 per cent of its
weight; but the amount of loss differs in different breeds, and this is of
importance to the cultivator. The cocoon in the different races presents
characteristic differences; being large or small;--nearly spherical with no
constriction, as in the Race de Loriol, or cylindrical, with either a deep
or slight constriction in the middle; with the two ends, or with one end
alone, more or less pointed. The silk varies in fineness and quality, and
in being nearly white, but of two tints, or yellow. Generally the colour of
the silk is not strictly inherited: but in the chapter on Selection I shall
give a curious account how, in the course of sixty-five generations, the
number of yellow cocoons in one breed has been reduced in France from one
hundred to thirty-five in the thousand. According to Robinet, the white
race, called Sina, by careful selection during the last seventy-five years,
"est arrivee a un tel etat de purete, qu'on ne voit pas un seul cocon jaune
dans des millions de cocons blancs." (8/75. Robinet ibid pages 306-317.)
Cocoons are sometimes formed, as is well known, entirely destitute of silk,
which yet produce moths; unfortunately Mrs. Whitby was prevented by an
accident from ascertaining whether this character would prove hereditary.
ADULT STAGE.
I can find no account of any constant difference in the moths of the most
distinct races. Mrs. Whitby assured me that there was none in the several
kinds bred by her; and I have received a similar statement from the eminent
naturalist, M. de Quatrefages. Captain Hutton also says (8/76. 'Transact.
Ent. Soc.' ut supra page 317.) that the moths of all kinds vary much in
colour, but in nearly the same inconstant manner. Considering how much the
cocoons in the several races differ, this fact is of interest, and may
probably be accounted for on the same principle as the fluctuating
variability of colour in the caterpillar, namely, that there has been no
motive for selecting and perpetuating any particular variation.
The males of the wild Bombycidae "fly swiftly in the day-time and evening,
but the females are usually very sluggish and inactive." (8/77. Stephen's
Illustrations, 'Haustellata' volume 2 page 35. See also Capt. Hutton
'Transact. Ent. Soc.' ibid page 152.) In several moths of this family the
females have abortive wings, but no instance is known of the males being
incapable of flight, for in this case the species could hardly have been
perpetuated. In the silk-moth both sexes have imperfect, crumpled wings,
and are incapable of flight; but still there is a trace of the
characteristic difference in the two sexes; for though, on comparing a
number of males and females, I could detect no difference in the
development of their wings, yet I was assured by Mrs. Whitby that the males
of the moths bred by her used their wings more than the females, and could
flutter downwards, though never upwards. She also states that, when the
females first emerge from the cocoon, their wings are less expanded than
those of the male. The degree of imperfection, however, in the wings varies
much in different races and under different circumstances. M. Quatrefages
(8/78. 'Etudes sur les Maladies du Ver a Soie' 1859 pages 304, 209.) says
that he has seen a number of moths with their wings reduced to a third,
fourth, or tenth part of their normal dimensions, and even to mere short
straight stumps: "il me semble qu'il y a la un veritable arret de
developpement partiel." On the other hand, he describes the female moths of
the Andre Jean breed as having "leurs ailes larges et etalees. Un seul
presente quelques courbures irregulieres et des plis anormaux." As moths
and butterflies of all kinds reared from wild caterpillars under
confinement often have crippled wings, the same cause, whatever it may be,
has probably acted on silk-moths, but the disuse of their wings during so
many generations has, it may be suspected, likewise come into play.
The moths of many breeds fail to glue their eggs to the surface on which
they are laid (8/79. Quatrefages 'Etudes' etc. page 214.) but this
proceeds, according to Capt. Hutton (8/80. 'Transact. Ent. Soc.' ut supra
page 151.), merely from the glands of the ovipositor being weakened.
As with other long-domesticated animals, the instincts of the silk-moth
have suffered. The caterpillars, when placed on a mulberry-tree, often
commit the strange mistake of devouring the base of the leaf on which they
are feeding, and consequently fall down; but they are capable, according to
M. Robinet (8/81. 'Manuel de l'Educateur' etc. page 26.) of again crawling
up the trunk. Even this capacity sometimes fails, for M. Martins (8/82.
Godron 'De l'Espece' page 462.) placed some caterpillars on a tree, and
those which fell were not able to remount and perished of hunger; they were
even incapable of passing from leaf to leaf.
Some of the modifications which the silk-moth has undergone stand in
correlation with one another. Thus, the eggs of the moths which produce
white cocoons and of those which produce yellow cocoons differ slightly in
tint. The abdominal feet, also, of the caterpillars which yield white
cocoons are always white, whilst those which give yellow cocoons are
invariably yellow. (8/83. Quatrefages 'Etudes' etc. pages 12, 209, 214.) We
have seen that the caterpillars with dark tiger-like stripes produce moths
which are more darkly shaded than other moths. It seems well established
(8/84. Robinet 'Manuel' etc. page 303.) that in France the caterpillars of
the races which produce white silk, and certain black caterpillars, have
resisted, better than other races, the disease which has recently
devastated the silk-districts. Lastly, the races differ constitutionally,
for some do not succeed so well under a temperate climate as others; and a
damp soil does not equally injure all the races. (8/85. Robinet ibid page
15.)]
From these various facts we learn that silk-moths, like the higher animals,
vary greatly under long-continued domestication. We learn also the more
important fact that variations may occur at various periods of life, and be
inherited at a corresponding period. And finally we see that insects are
amenable to the great principle of Selection.