64 HOESES. Chap. II 



preserved. In South America in the time of Azara, when 

 the horse had been feral for about 250 years, 90 out of a 100 

 horses were " bai-ehatains," and the remaining ten were 

 " zains," that is brown ; not more than one in 2000 being 

 black. In North America the feral horses show a strong 

 tendency to become roans of various shades ; but in certain 

 parts, as I hear from Dr. Canfield, they are mostly duns and 

 striped. 42 



In the following chapters on the Pigeon we shall see that a 

 blue bird is occasionally produced by pure breeds of various 

 colours and that when this occurs certain black marks in- 

 variably appear on the wings and tail ; so again, when vari- 

 ously coloured breeds are crossed, blue birds with the same 

 black marks are frequently produced. "We shall further see 

 that these facts are explained by, and afford strong evidence 

 in favour of, the view that all the breeds are descended 

 from the rock-pigeon, or Columba livia, which is thus coloured 

 and marked. But the appearance of the stripes on the 

 various breeds of the horse, when of a dun colour, does not 

 afford nearly such good evidence of their descent from a 

 single primitive stock as in the case of the pigeon : because 

 no horse certainly wild is known as a standard of comparison ; 

 because the stripes when they appear are variable in cha- 

 ra iter; because there is far from sufficient evidence that the 

 crossing of distinct breeds produces stripes, and lastly, 

 because all the species of the genus Equus have the spinal 

 stripe, and several sjiecies have shoulder and leg stripes. 

 Nevertheless the similarity in the most distinct breeds in 

 their general range of colour, in their dappling, and in the 

 occasional appearance, especially in duns, of leg-stripes and 

 of double or triple shoulder stripes, taken together, indicate 



42 Azara, ' Quadrupeds du Para- describes two wild horses from Mexico 



guay,' torn. ii. p. 307. In North as roan. In the Falkland Islands, 



America, Catlin (vol. ii. p. 57) de- where the horse has been feral onlv 



scribes the wild horses, believed to between 60 and 70 years, I was told 



have descended from the Spanish that roans and iron-grevs were the 



horses of Mexico, as of all colours, prevalent colours. These several fact.s 



black, grey, r.>an. and roan pied with show that horses do not soon revert 



sorrel. F. Michaux ( ' Travels in to any uniform coW~ 

 North America,' ting, translat., p. 235) 



