INHERITANCE IN RAGE HORSES 95 



lis take the case of " Tsu Sliima," mentioned in 

 Mr. Bunsow's article. She is entered in the Stud 

 Book as a grey, but Mr, Huby, the stud groom of 

 the Duke of Portland's stud, at Welbeck, in a letter 

 to Mr. Bunsow, says : " When I saw her last she 

 was not grey at all, although she had a tuft of grey 

 hair at the root of her tail. She is now a brown 

 mare." The case of " Postumus " is interesting in 

 the same way. He was born a brown colour, and 

 Mr. Huby says : " It was only in the Autumn of the 

 year he was foaled that he became grey. He is a 

 .good grey now, and every time he sheds his coat he 

 will become whiter still ; by the time he is five or 

 six years old he will be white. His dam is now 

 white, and previously always had been a good grey." 

 This statement of Mr. Huby's is interesting because 

 it appears to express, in the form of a prediction, 

 the result of his experiences. It suggests that in 

 his experience grey horses in some cases turn whiter 

 with each moult, until they become what are called 

 white horses. It is further of still greater interest 

 because it suggests that this capacity of changing 

 colour is itself hereditarily transmitted. That sug- 

 gestion is intimated in the statement that "his dam 

 was previously a good grey and is now white," and 

 in that relating to her son, "that he is a good grey 

 now and will become whiter with each moult." It 

 is a matter of some importance to note whether this 

 change in " Postumus " will actually occur. 



The question of colour-change with age is one 

 worthy of a fuller investigation. It appears not to 



G 



