408 Mr. R. I. Pocock on the Cuhmrs of 



all tliese stripes may coexist in one individual. Some exhibit 

 only the spinal stripe, but when the legs or shoulders are 

 barred the spinal stripe appears to be always present as well ; 

 just as in the Asiatic asses, while stripes on the legs and 

 shoulders may or may not be detectable, the spinal stripe is 

 of invariable occurrence. 



It is also known that the foals of some horses, especially 

 duns, may show on parts of the body other than those 

 specified faint stripes which usually disappear with the first 

 moult; and Hagenbeck recorded the presence of such 

 evanescent stripes upon the foals of the wild Mongolian 

 Prjevalsky's horses. \Yith the exception of this last circum- 

 stance, all the above enumerated facts connected with the 

 striping of horses were well known to Darwin *, and he 

 drew from them the conclusion that domestic breeds of 

 horses are descended from a single wild species which was 

 dun in colour and marked more or less with dark stripes. 

 That portion of this view which relates to the presence of 

 black stripes in the ancestral stock is generally accepted at 

 the present time. Nevertheless it must be remembered that 

 dappling or pummel-marking, as it is sometimes called, is a 

 far more usual pattern in domestic horses than stripes. 

 It occurs commonly in bays and blacks, more rarely in 

 chestnuts, is not unknown in duns, and attains its highest 

 perfection in dapple-greys. 



In horses of this colour the pattern may be described as 

 consisting of white spots upon a black or blackish-grey 

 ground, or of a black or blackish-grey network with white 

 interspaces, in just the same way as zebras have been stated 

 to be black-striped or white-striped according to the fancy 

 of the describer. When dappling occurs in bays the network 

 is black on the bay ground, and in blacks the dappling 

 stands out against the dark ground-colour on account of 

 the greater intensity of its tone or of a difference in the sheen 

 of the hairs, precisely as is the case in the spots of black 

 leopards or the marbling of tabby cats. 



Now it is admittedly possible that "dappling" is a sport 

 without phylogenetic significance. This, however, has not 

 been always held. Darwin suspected that dappling was a 

 modification of the striped pattern f with which he believed 



* For a more recent and detailed discussion of this subject, see 

 Prof. Ewart's ' Penycuick Expeiimeuts,' pp. 100-134 (1899). 



t This is not exactly Prof. Ewart's opinion. He said : " Dappling, I 

 believe, has been acquired since the ancestral stripes were all but lost. 

 AVhen dappling coexists with more or less distinct stripes it is at once 

 evident .... that the one has not been derived from the other. The 



I 



