IX 
PREFACE. 
various ways; while, on the other hand, by rearing an inferior breed in situations where one 
of greater value could be maintained, we deprive ourselves of the profit which the natural or 
acquired advantages of our situation present. These are errors of practice frequently com¬ 
mitted, to the injury of breeders, and the loss of the country. 
An error of another kind is the subject of constant observation, the result likewise of im¬ 
perfect knowledge of the distinctive characters of breeds. F or the adaptation of a breed to 
the situation in which it is to be reared, two general methods may be pursued; either a new 
breed may be substituted for that which exists, or the old one may have its characters modi¬ 
fied or changed by crossing with other races. There are many cases in which scarce an 
error can be committed in this species of improvement, provided we resort to a really superior 
race; but there are many other cases in which even this kind of change may be injurious, or 
attended with doubtful benefit. Animals become gradually adapted to the conditions in 
which they are placed, and many breeds have accordingly become admirably suited to the 
natural state of the country in which they have been acclimated. Thus the West Highland 
Breed of cattle has become suited to a humid climate and a country of mountains; the beauti¬ 
ful breed of North Devon, to a country of lesser altitude and milder climate. In these, and 
many cases more, an intermixture of stranger blood might destroy the characters which time 
had imprinted on the stock, and give as the result a progeny inferior in useful properties to 
either of the parent races. Not only have individual breeders erred in the application of this 
kind of crossing, but it is certain that several entire breeds have been lost which ought to 
have been carefully preserved. There are many breeds, indeed, so defective in themselves, 
that time and capital would have been lost in endeavouring to cultivate them; but not a few, 
as will be seen in the sequel, might have been improved to the degree required, by mere 
selection of parents, and attention to the known principles of breeding. 
Not only do animals become adapted in constitution, temperament, and habits, to the 
situations in which they have been naturalized, but characters communicated by art become 
permanent by continued reproduction. Thus, in the case of the Dairy Breed of Ayrshire, by 
breeding from females that possess the property of yielding a large quantity of milk, a pecu¬ 
liar breed has been at length formed, exceedingly well suited to the purposes of the dairy, and 
at the same time hardy and fitted to subsist on ordinary food. Now, such a breed might be 
injured, and not improved, by crossing, even with a race superior to itself in many properties. 
Thus, a cross with the Durhams or Herefords, would produce a race of larger size and supe¬ 
rior fattening properties to the native race; but even in these properties, the progeny would 
be inferior to either the Herefords or the Durhams, and inferior to the Ayrshire itself, as a 
hardy race of dairy cattle. Thus the crossing of oxen with a race apparently superior, will 
not always be attended with ultimate good; and caution and knowledge of the end to be ar¬ 
rived at are required even in the cases where the good seems most easily attained. 
Another error of a very different kind, but proceeding likewise from ignorance of the 
relative value of breeds, prevails to a great extent. Breeds, in themselves bad, are obsti¬ 
nately retained in districts fitted to support superior races. In every part of the kingdom, 
we see in existence wretched breeds, unworthy of being preserved, while the easiest means 
are at the command of the farmer of supplying their place by others suited to the locality. 
