'Youatt on Cattle' page 193. A full account of this bull is taken from Marshall.); yet in the hands of Mr. Fowler, this bull greatly improved his race. We have also reason to believe that selection, carried on so far unconsciously that there was at no one time any distinct intention to improve or change the breed, has in the course of time modified most of our cattle; for by this process, aided by more abundant food, all the lowland British breeds have increased greatly in size and in early maturity since the reign of Henry VII. (3/72. 'Youatt on Cattle' page 116. Lord Spencer has written on this same subject.) It should never be forgotten that many animals have to be annually slaughtered; so that each owner must determine which shall be killed and which preserved for breeding. In every district, as Youatt has remarked, there is a prejudice in favour of the native breed; so that animals possessing qualities, whatever they may be, which are most valued in each district, will be oftenest preserved; and this unmethodical selection assuredly will in the long run affect the character of the whole breed. But it may be asked, can this rude kind of selection have been practised by barbarians such as those of southern Africa? In a future chapter on Selection we shall see that this has certainly occurred to some extent. Therefore, looking to the origin of the many breeds of cattle which formerly inhabited the several districts of Britain, I conclude that, although slight differences in the nature of the climate, food, etc., as well as changed habits of life, aided by correlation of growth, and the occasional appearance from unknown causes of considerable deviations of structure, have all probably played their parts; yet that the occasional preservation in each district of those individual animals which were most valued by each owner has perhaps been even more effective in the production of the several British breeds. As soon as two or more breeds were formed in any district, or when new breeds descended from distinct species were introduced, their crossing, especially if aided by some selection, will have multiplied the number and modified the characters of the older breeds.

SHEEP.

I shall treat this subject briefly. Most authors look at our domestic sheep as descended from several distinct species. Mr. Blyth, who has carefully attended to the subject, believes that fourteen wild species now exist, but "that not one of them can be identified as the progenitor of any one of the interminable domestic races." M. Gervais thinks that there are six species of Ovis (3/73. Blyth on the genus Ovis in 'Annals and Mag. of Nat. History' volume 7 1841 page 261. With respect to the parentage of the breeds see Mr. Blyth's excellent articles in 'Land and Water' 1867 pages 134, 156. Gervais 'Hist. Nat. des Mammiferes' 1855 tome 2 page 191.) but that our domestic sheep form a distinct genus, now completely extinct. A German naturalist (3/74. Dr. L. Fitzinger 'Ueber die Racen des Zahmen Schafes' 1860 s. 86.) believes that our sheep descend from ten aboriginally distinct species, of which only one is still living in a wild state! Another ingenious observer (3/75. J. Anderson 'Recreations in Agriculture and Natural History' volume 2 page 264.), though not a naturalist, with a bold defiance of everything known on geographical distribution, infers that the sheep of Great Britain alone are the descendants of eleven endemic British forms! Under such a hopeless state of doubt it would be useless for my purpose to give a detailed account of the several breeds; but a few remarks may be added.

Sheep have been domesticated from a very ancient period. Rutimeyer (3/76. 'Pfahlbauten' s. 127, 193.) found in the Swiss lake-dwellings the remains of a small breed, with thin tall legs, and horns like those of a goat, thus differing somewhat from any kind now known. Almost every country has its own peculiar breed; and many countries have several breeds differing greatly from each other. One of the most strongly marked races is an Eastern one with a long tail, including, according to Pallas, twenty vertebrae, and so loaded with fat that it is sometimes placed on a truck, which is dragged about by the living animal.

Charles Darwin

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