is asserted with equal
confidence, and probably with the same amount of actual proof, that it
would be impossible so to improve the wild hog by selection as to render
it the equal of the domesticated hog. There must, therefore, have been
an infusion of blood of a cultivated breed of pigs to acquire even that
amount of success which was noticeable in the improved pig of a century,
or less, ago. Unfortunately, for this argument, it has not been possible
to obtain any information of value as to the alleged source of origin of
this cultivated breed of pigs.

Again, those pigs which possess in a marked degree early maturity, fine
quality of flesh, and those other characteristics of the improved pig,
are so various in colour, that one cultivated breed only could not have
been utilised in the general improvement.

All the ancient writers on pigs appear to have experienced the same
difficulty when endeavouring to discover the sources of origin of the
material which might have been used in the production of the pig which
in their time was looked upon as the domesticated and improved pig of
the period. This difficulty extends even to the present day. So far as
is known there exists no actual proof that the domesticated hog has been
evolved in any particular way other than by continued selection of those
animals for breeding purposes which possessed in the greatest degree
those particular qualities held in the highest estimation at the time.

Of course, the soil, climate, etc., of the district in which pigs are
reared have a certain amount of influence, but this is noticeable to a
much lesser extent with pigs than with horses, cattle, or sheep, since
under the present system of pig-breeding the greater portion of the food
used in the different districts is of a very similar character--indeed,
much of it has a common origin--having been imported from abroad.

As a rule, comparatively speaking very little difference is noticeable
in the development, form, and character of pigs bred in the various
parts of the country, whereas with some of the other domesticated
animals a very considerable change follows the removal of sheep of a
pure breed from one district to another. The quality and quantity of the
wool, flesh, and bone are all affected. An exactly similar effect is
noticeable when horses of a particular breed are moved from one district
to another. For instance, a Shire foal bred in the Fens may possess the
characteristic bon