54 THE HORSE AND ITS RELATIVES 



occurrence of dappling in horses of all colours, and 

 suggested that it must be a very deep-seated and 

 ancient character of the group. He even went so 

 far as to suggest that the dappling of the horse 

 represents the rosettes on the leopard's skin, and 

 that the latter are derived from the pattern on the 

 bony plates of the armour of the extinct giant arma- 

 dillos, or glyptodonts, of South America. 



Now although this theory is certainly untenable 

 it has the merit of recognising that dappling is a 

 feature deeply implanted in the equine nature. 



Giving full credit to the discoverer of this fact, 

 Mr. R. I. Pocock,^ who has done much to illustrate 

 the meaning of animal coloration, has taken up the 

 subject of the colours of domesticated horses, and 

 concludes that their colouring may be classed under 

 three main types. The first of these types com- 

 prises bays, blacks, chestnuts, roans, piebalds, and 

 skewbalds ; the second includes duns alone ; while 

 the third is represented by greys and the majority 

 of whites. From the fact that in all wild members 

 of the horse family the mane and tail are darker in 

 colour than the body, it is inferred that bay is the 

 original phase of the first type. On this phase 

 three modifications have been working, namely, 

 blackness, or melanism, to give rise to browns and 

 blacks ; redness, or erythrism, to produce chest- 

 nuts ; and whiteness, or albinism, to develop (in 



^ Ann. Mag. Nat. Hist., London, ser. 8, vol. iv. p. 404, 1909. 



