424 CONCLUDING EEMARKS. Chap. XXVIII. 



individuals which revert or vary, and by the preservation of 

 those which still inherit the new character. Hence, although 

 some few animals have varied rapidly in certain respects 

 under new conditions of life, as dogs in India and sheep in 

 the West Indies, yet all the animals and plants which have 

 produced strongly marked races were domesticated at an 

 extremely remote epoch, often before the dawn of history. As 

 a consequence of this, no record has been preserved of the 

 origin of our chief domestic breeds. Even at the present day 

 new strains or sub-breeds are formed so slowly that their first 

 appearance passes unnoticed. A man attends to some par- 

 ticular character, or merely matches his animals with unusual 

 care, and after a time a slight difference is perceived by his 

 neighbours ; — the difference goes on being augmented by un- 

 conscious and methodical selection, until at last a new sub- 

 breed is formed, receives a local name, and spreads ; but by 

 this time its history is almost forgotten. When the new 

 breed has spread widely, it gives rise to new strains and sub- 

 breeds, and the best of these succeed and spread, supplanting 

 other and older breeds ; and so always onwards in the march 

 of improvement. 



When a well-marked breed has once been established, if not 

 supplanted by still further improved sub-breeds, and if not 

 exposed to greatly changed conditions of life inducing further 

 variability or reversion to long-lost characters, it may ap- 

 parently last for an enormous period. We may infer that this 

 is the case from the high antiquity of certain races ; but some 

 caution is necessary on this head, for the same variation may 

 appear independently after long intervals of time, or in distant 

 places. We may safely assume that this has occurred with the 

 turnspit-dog, of which one is figured on the ancient Egyptian 

 monuments — with the solid-hoofed swine 11 mentioned by 

 Aristotle — with five-toed fowls described by Columella — and 

 certainly with the nectarine. The dogs represented on the 

 Egyptian monuments, about 2000 B.C., show us that some of 

 the chief breeds then existed, but :t is extremely doubtful 

 whether any are identically the same with our present breeds. 

 A great mastiff sculptured on an Assyrian tomb, 640 B.C., is 

 11 Godron, <De l'Espfece,* torn, i., 1859, p. 368. 



