VARIATION UNDER DOMESTICATION 69 



have a distinct name, and from being only i3lightly 

 valued, their history will have been disregarded. When 

 further improved by the same slow and gradual process, 

 they will spread more widely, and will be recognized as 

 something distinct and valuable, and will then probably 

 first receive a provincial name. In semi-civilized coun- 

 tries, with little free communication, the spreading of a 

 new sub-breed would be a slow process. As soon as the 

 points of valae are once acknowledged, the principle, as 

 I have called it, of unconscious selection will always 

 tend — perhaps more at one period than at another, as 

 the breed rises or falls in fashion — perhaps more in one 

 district than in another, according to the state of civiliza- 

 tion of the inhabitants — slowly to add to the characteristic 

 features of the breed, whatever they may be. But the 

 chance will be infinitely small of any record having been 

 preserved of such slow, varying, and insensible changes. 



Circumstances favorable to Man^s Power of /Selection 



I will now say a few words on the circumstances, 

 favorable or the reverse, to man's power of selection. A 

 high degree of variability is obviously favorable, as freely 

 giving the materials for selection to work on; not that 

 mere individual differences are not amply sufficient, with 

 extreme care, to allow of the accumulation of a large 

 amount of modification in almost any desired direction. 

 But as variations manifestly useful or pleasing to man 

 appear only occasionally, the chance of their appearance 

 will be much increased by a large number of individ- 

 uals being kept. Hence, number is of the highest im- 

 portance for success. On this principle Marshall for- 

 merly remarked, with respect to the sheep of parts of 



