THE HORSE 97 



and in some of the domestic birds ; but so far as we know, 

 there has been no other useful result from the hybridizing, if 

 it has occurred. Moreover, the mule is unique for the fact 

 that the animal is distinctly stronger for its weight, and more 

 enduring than either species which his blood combines. In 

 fact, there is no product of man's industry in relation to 

 domesticated animals which is more interesting than this 

 singular creature. At present, its use appears to be going 

 out of vogue ; the evidence goes to show that the hybrid j| 

 has no place in the affections of mankind, and that it is only v 

 likely to be kept in its use in tropical countries, and partic- 

 ularly in regions where the beasts have to be under the care 

 of slaves or other negligent folk. It is a singular fact in 

 connection with this hybrid, that it is nearly absolutely ' 

 sterile, there being only two or three cases on record in which 

 they have proved fecund. It seems, however, possible that if 

 these rare instances of continued breeding were to be duly 

 used, an intermediate species might be permanently estab- 

 lished. This is, indeed, one of the most important lines for 

 experiment which could be undertaken by an institution 

 devoted to the study of problems relating to domestication. 

 It is commonly thought that a mule is a stupider creature 

 than the horse ; but I have never found a person, who was well 

 acquainted with both animals, who hesitated to place the 

 mongrel in the intellectual grade above the pure-blood ani- 

 mal. There is, it is true, a decided difference in the mental 

 qualities of the two creatures. The mule is relatively unde- 

 monstrative, its emotions being sufficiently expressed by an 

 occasional bray a mode of utterance which he has inherited 

 from the humbler side of his house in a singularly unchanged 

 way. Even in the best humor it appears sullen, and lacks 

 7 



