INTERESTING FEATURES IN HORSES, ETC. 185 



groups, and tended to merge them into larger assemblages. They 

 show that animal organisation is more flexible than our knowledge 

 of recent forms might have led us to believe ; and that many 

 structural permutations and combinations [I would take the liberty 

 of adding skin features], 1 of which the present world gives us no 

 indication, may nevertheless have existed. 



'But it by no means follows, because the Palceotherium has 

 much in common with the Horse, on the one hand, and with the 

 Rhinoceros on the other, that it is the intermediate form through 

 which Rhinoceroses have passed to become Horses, or vice-versa ; on 

 the contrary, any such supposition would certainly be erroneous.' 2 



As I said, there is no fixity of coloration round the eye or other 

 part, as it may dwindle and disappear altogether, or it may invade 

 adjacent parts. Those animals which have a complete circle round 

 the eye, whether white, black, or tan-coloured, are survivals of a stage 

 which at one time may have been general, and the spot over the 

 eye of the black and tan Dog may be only a remnant of a former 

 complete circle round the eye. 



. On one occasion I saw a jet black Persian Cat. The tips of all 

 its four feet were white ; it had a white patch on its chest, and a 

 little white on its abdomen ; its whiskers and eye hairs were white. 

 There was no contrast of colour round the eye and round the 

 lips both being jet black ; but these white whiskers and eye hairs 

 were seemingly the only remnants of surfaces differently coloured 

 from the body. 



There are other curious marks in some mammals which are not 

 so easily accounted for ; such as the white tip of the tail in many 

 Dogs to which I have already alluded, and a white patch which one 

 sees so frequently on the chest of Dogs. There can hardly be much 



1 The parenthesis is mine. 



2 ' Science and Hebrew Tradition.' Lectures on Evolution, p. 102. 



