Chap. XXVIIl. CONCLUDING REMARKS. 421 



there is, througli the prolonged action of methodical and 

 unconscious selection, a constant tendency in every breed to 

 become more and more different from its parent-stock ; and 

 when several breeds have been produced and are valued for 

 different qualities, to differ more and more from each other. 

 This leads to Divergence of Character. As improved sub- 

 varieties and races are slowly formed, the older and less 

 improved breeds are neglected and decrease in number. When 

 few individuals of any breed exist within the same locality, 

 close interbreeding, by lessening their vigour and fertility, 

 aids in their final extinction. Thus the intermediate links 

 are lost, and the remaining breeds gain in Distinctness of 

 Character. 



In the chapters on the Pigeon, it was proved by historical 

 evidence and by the existence of connecting sub-varieties in 

 distant lands that several breeds have steadily diverged in 

 character, and that many old and intermediate sub-breeds 

 have been lost. Other cases could be adduced of the extinc- 

 tion of domestic breeds, as of the Irish wolf-dog, the old 

 English hound, and of two breeds in France, one of which 

 was formerly highly valued.* Mr. Pickering remarks ^ that 

 " the sheep figured on the most ancient Egyj)tian monuments 

 " is unknown at the present day ; and at least one variety of 

 " the bullock, formerly known in Egypt, has in like manner 

 " become extinct." So it has been with some animals and 

 with several plants cultivated by the ancient inhabitants of 

 Europe during the neolithic period. In Peru, Von Tschudi ^ 

 found in certain tombs, apparently prior to the dynasty of the 

 Incas, two kinds of maize not now known in the country. 

 With our flowers and culinary vegetables, the production of 

 new varieties and their extinction has incessantly recurred. 

 At the present time improved breeds sometimes displace older 

 breeds at an extraordinarily rapid rate ; as has recently occurred 

 throughout England with pigs. The Long-horn cattle in 

 their native home were " suddenly swept away as if by some 

 " murderous pestilence," by the introduction of Short-horns.'^ 



* M. Rufz de LavisoE, in ' Bull. Soc. p. 177. 



Imp. d'Acclimat.,' Dec. 1862, p. 10U9. ^ Youatt on Cattle, 1834, p. 200. 



» 'Races of Man,' 1850, p. 315. On Pigs, see ' Gard. Chronicle,' 1854 



* 'Travels in Peru,' Eag. Translat,, p. 410. 



40 



