CHAPTER II. 



THE MULE 



As is generally known the mule is a cross between 

 the jack or male ass and the mare. The opposite 

 cross, or that between the stallion and the jennet or 

 female ass, is known as the hinny and is also quite 

 frequently met with. In general, the mule is con- 

 sidered quite superior in all respects to the hinny 

 and is almost the only hybrid form between the 

 horse and the ass which is used on a commercial 

 scale. It is a curious fact that while all species of 

 the horse genus readily cross with one another and 

 produce hybrids, all of these hybrids are sterile. 

 Thus hybrids are known between the horse and ass, 

 zebra and quagga. None of these hybrids have 

 ever been known to produce offspring. Occasion- 

 ally claims have been set up regarding the existence 

 of fertile mules, but such claims have proved to be 

 unfounded. The cross between the mare and the 

 male zebra is known as the zebroid and has been 

 experimented with quite extensively in England and 

 Brazil. Furthermore, recently the Bureau of 

 Animal Industry has begun some experiments 

 along this line. From observations of the zebroid 

 in Brazil claims have been set up that this hybrid 

 is more graceful than the mule and more docile. 

 However that may be, the only important hy- 

 brid between the horse and the ass, so far as we are 

 concerned, is the mule. 



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