HABITS AND HAIR OF UNGULATES 83 



The pectoral and inguinal regions of the domestic horse are 

 two of the most valuable fields in the mammalian body for study- 

 ing the formation by muscular action of patterns of hair, for this 

 animal is the locomotive animal par excellence. Here the process 

 has been carried to the extreme limit, and these two are prominent 

 examples among the characters to which I drew attention in a 

 paper published in the Proceedings of the Zoological Society of London, 

 " On proposed additions to the accepted systematic characters of 

 certain Mammals," June 9th, 1904, Vol. I. I am still of the opinion 

 that they deserve " Flag rank," though they have not yet been 

 promoted . Be that as it may I think it may be well here to compare 

 two animals belonging to the family Equidse, the horse and zebra, 

 which resemble one another very closely in form — in respect of 

 these patterns. 



Horse and Zebra Compared. 



If a horse of the hackney type and a zebra were skinned and 

 the bodies of the two animals then examined I suppose a competent 

 anatomist would find some difficulty in distinguishing one from 

 the other so closely do these two allied species of equidse, one 

 wild and the other domesticated, resemble one another in structure. 

 But in this as in many other questions form is not to be considered 

 alone. The colouration of the two animals is strikingly different, 

 but, in its humble way, the difference of their patterns of hair- 

 arrangement is worthy of notice. The horse in different specimens 

 chosen from a large group will exhibit patterns in the frontal, 

 pectoral and inguinal regions constantly, and variably in less common 

 regions, axillary, cervical and gluteal, that is to say, in six different 

 areas. I have examined many zebras, living and dead, and find no 

 constant pattern in the whole of its large surface of skin except an 

 ill -developed frontal and a very small cervical one — two in all. 

 The mere numerical difference is not the only important one, 

 for the insignificance of the size of the two zebra patterns and the 

 constancy and high development of many of those of the horse 

 are not less significant from the present point of view. I submit 

 that these two animals carry about with them on their hairy coats 

 indubitable records of their personal and ancestral habits. Atten- 

 tion to the facts of a horse's life and certain related and contrasted 

 facts of the lives of other animals, of which the zebra may be taken 

 as a type, will show the reasons why these patterns are to be looked 

 upon as registers of long-past and present activities of the species 

 concerned. The horse has been developed out of a wild plastic 

 stock with some such ancestors as the wild horse of Przewalski, 



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