

244 SELECTION. Chap. XXI. 



It is scarcely possible to overrate the effects of selection 



in number, and history shows us how wonderfully they have 

 increased since the earliest records. 67 As each new variety is 

 produced, the earlier, intermediate, and less valuable forms will 

 be neglected, and perish. When a breed, from not being valued, 

 is kept in small numbers, its extinction almost inevitably 

 follows sooner or later, either from accidental causes of destruc- 

 tion or from close interbreeding ; and this is an event which, in 

 the case of well-marked breeds, excites attention. The birth or 

 production of a new domestic race is so slow a process that it 



65 Youatt on Cattle, pp. 116, 128. 66 < Domesticated Animals/ p. 188. 



6 ? Volz, ' Beitrage zur Kulturgeschichte,' 1852, s. 99 et passim. 



occasionally carried on in various ways and places during 

 thousands of generations. All that we know, and, in a still 



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stronger degree, all that we do not know, 65 of the history of the 

 great majority of our breeds, even of our more modern breeds, * 



agrees with the view that their production, through the action 

 of unconscious and methodical selection, has been almost insen- 

 sibly slow. When a man attends rather more closely than is 

 usual to the breeding of his animals, he is almost sure to improve 

 them to a slight extent. They are in consequence valued in 

 his immediate neighbourhood, and are bred by others ; and their 

 characteristic features, whatever these may be, will then slowly 

 but steadily be increased, sometimes by methodical and almost 

 always by unconscious selection. At last a strain, deserving to 

 be called a sub-variety, becomes a little more widely known, 

 receives a local name, and spreads. The spreading will have been 

 extremely slow during ancient and less civilised times, but now 

 is rapid. By the time that the new breed had assumed a some- 

 what distinct character, its history, hardly noticed at the time, 

 will have been completely forgotten; for, as Low remarks, 66 

 " we know how quickly the memory of such events is effaced." 



As soon as a new breed is thus formed, it is liable through 

 the same process to break up into new strains and sub- 

 varieties. For different varieties are suited for, and are valued 

 under, different circumstances. Fashion changes, but, should 

 a fashion last for even a moderate length of time, so strong 

 is the principle Of inheritance, that some effect will probably 

 be impressed on the breed. Thus varieties go on increasing 





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