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Export to Excel select * from OriginOfSpecies where ordinal = '30' order by subject, title, ordinal limit 4 (Page 1: Row)
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01 - Variations Under Domestication 01-01 - Causes of Variability 30 I may add, that as some organisms breed freely under the most unnatural conditions (for instance, rabbits and ferrets kept in hutches), showing that their reproductive organs are not easily affected;

rabbit
rabbit

ferret
ferret


so will some animals and plants withstand domestication or cultivation, and vary very slightly- perhaps hardly more than in a state of nature. Some naturalists have maintained that all variations are connected with the act of sexual reproduction;

but this is certainly an error; for I have given in another work a long list of "sporting plants," as they are called by gardeners;- that is, of plants which have suddenly produced a single bud with a new and sometimes widely different character from that of the other buds on the same plant.

These bud variations, as they may be named, can be propagated by grafts, offsets, &c., and sometimes by seed.

graft
graft


They occur rarely under nature, but are far from rare under culture.

As a single bud out of the many thousands, produced year after year on the same tree under uniform conditions, has been known suddenly to assume a new character; and as buds on distinct trees, growing under different conditions, have sometimes yielded nearly the same variety- for instance, buds on peach-trees producing nectarines, and buds on common roses producing moss-roses- we clearly see that the nature of the conditions is of subordinate importance in comparison with the nature of the organism in determining each particular form of variation;-
bud
bud

tree
tree

peach
peach

nectarine
nectarine

rose
rose

Moss Rose
Moss Rose


perhaps of not more importance than the nature of the spark, by which a mass of combustible matter is ignited, has in determining the nature of the flames.
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01 - Variations Under Domestication 01-04 - Inheritance 30 The laws governing inheritance are for the most part unknown.

No one can say why the same peculiarity in different individuals of the same species, or in different species, is sometimes inherited and sometimes not so; why the child often reverts in certain characters to its grandfather or grandmother or more remote ancestor; why a peculiarity is often transmitted from one sex to both sexes, or to one sex alone, more commonly but not
exclusively to the like sex.

It is a fact of some importance to us, that peculiarities appearing in the males of our domestic breeds are often transmitted, either exclusively or in a much greater degree, to the males alone.

A much more important rule, which I think may be trusted, is that, at whatever period of life a peculiarity first appears, it tends to reappear in the offspring at a corresponding age, though sometimes earlier. In many cases this could not be otherwise;

thus the inherited peculiarities in the horns of cattle could appear only in the offspring when nearly mature; peculiarities in the silkworm are known to appear at the corresponding caterpillar or cocoon stage.
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But hereditary diseases and some other facts make me believe that the rule has a wider extension, and that, when there is no apparent reason why a peculiarity should appear at any particular age, yet that it does tend to appear in the offspring at the same period at which it first appeared in the parent.

I believe this rule to be of the highest importance in explaining the laws of embryology.
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These remarks are of course confined to the first appearance of the peculiarity, and not to the primary cause which may have acted on the ovules or on the male element; in nearly the same manner as the increased length of the horns in the offspring from a short-horned cow by a long-horned bull, though appearing late in life, is clearly due to the male element.
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01 - Variations Under Domestication 01-07 - Origin of Domestic Varieties from one or more Species 30 Since the discovery of flint tools in the superficial formations of many parts of the world, all geologists believe that barbarian man existed at an enormously remote period;

flint
flint


and we know that at the present day there is hardly a tribe so barbarous, as not to have domesticated at least the dog.

The origin of most of our domestic animals will probably for ever remain vague.

But I may here state, that, looking to the domestic dogs of the whole world, I have, after a laborious collection of all known facts, come to the conclusion that several wild species of Canidae have been tamed, and that their blood, in some cases mingled together, flows in the veins of our domestic breeds. In regard to sheep and goats I can form no decided opinion.

dog
dog

sheep
sheep

goat
goat
01 - Variations Under Domestication 01-08 - Breeds of the Domestic Pigeons, their Differences and Origin 30 Altogether at least a score of pigeons might be chosen, which, if shown to an ornithologist, and he were told that they were wild birds, would certainly be ranked by him as well-defined species.

Moreover, I do not believe that any ornithologist would in this case place the English carrier, the short-faced tumbler, the runt, the barb, pouter, and fantail in the same genus; more especially as in each of these breeds several truly-inherited sub-breeds, or species, as he would call them, could be shown him.

English Carrier Pigeon
English Carrier Pigeon

Short Faced Tumbler Pigeon
Short Faced Tumbler Pigeon

Runt Pigeon
Runt Pigeon

Barb Pigeon
Barb Pigeon

Pouter Pigeon
Pouter Pigeon

Fantail Pigeon
Fantail Pigeon