244 FOWLS. Chap. Til 



in ancient times and in semi-civilized countries took pains to 

 keep the breeds distinct, and who therefore valued them, 

 would not occasionally have destroyed inferior "birds and occa- 

 sionally have preserved their best birds ? This is all that is 

 required. It is not pretended that any one in ancient times 

 intended to form a new breed, or to modify an old breed 

 according to some ideal standard of excellence. He who 

 cared for poultry would merely wish to obtain, and afterwards 

 to rear, the best birds which he could ; but this occasional 

 preservation of the best birds would in the course of time 

 modify the breed, as surely, though by no means as rapidly, 

 as does methodical selection at the present day, If one person 

 out of a hundred or out of a thousand attended to the breeding 

 of his birds, this would be sufficient ; for the birds thus tended 

 would soon become superior to others, and would form a new 

 strain ; and this strain would, as explained in the last chapter 

 slowly have its characteristic differences augmented, and at 

 last be converted into a new sub-breed or breed. But breeds 

 would often be for a time neglected and would deteriorate ; 

 they would, however, partially retain their character, and 

 afterwards might again come into fashion and be raised to a 

 standard of perfection higher than their former standard ; as 

 has actually occurred quite recently with Polish fowls. If, 

 however, a breed were utterly neglected, it would become 

 extinct, as has recently happened with one of the Polish sub- 

 breeds. Whenever in the course of past centuries a bird 

 appeared with some slight abnormal structure, such as with a 

 lark-like crest on its head, it would probably often have been 

 preserved from that love of novelty which leads some persons 

 in England to keep rumpless fowls, and others in India to 

 keep frizzled fowls. And after a time any such abnormal 

 appearance would be carefully preserved, from being esteemed 

 a sign of the purity and excellence of the breed ; for on this 

 principle the Romans eighteen centuries ago valued the fifth 

 toe and the white ear-lobe in their fowls. 



Thus from the occasional appearance of abnormal cha- 

 racters, though at first only slight in degree ; from the effects 

 of the use and the disuse of parts ; possibly from the direct 

 effects of changed climate and food ; from correlation of 



