82 



MULES AND MULE BREEDING. 



the ass appear to be ordinary mules, and are sterile, whereas 

 if she were a mule they should be three-fourths asinine and 

 only one-fourth equine, which is not the cage. Her progeny 

 by the horse are horses which have proved fertile. It 

 would appear most probable that this is not a case of a 

 fertile mule breeding ; but, that the animal is really an 

 ordinary mare, whose female parent was influenced by a first 

 alliance, as is so often the case in dogs and other animals. 



There is no doubt tha t the majority of th e accounts of 

 supposed ferti le mul esowe~"EE8lr oej^n to the fact tlia t 



Snormal 



lactation not unfrequently occurs in them, when 

 milk IS secreted m great abundanc e, and they may be seen 

 s uckling — the foals of other animals. This singular 

 phenoHreiTOnTi not confined to mules, but is well known to 

 occur in many other species. 



The m aternal instinct is one of the most powerful, and 

 there are numerous examples of its being ""s^ strongly 

 excited m iemalestotirer than the mother) m tavouiF of the 

 yotrng ot animals of the same, and even of different s pecies, 

 as-tcrdetermine the abundant secretion of milk. Domestic 

 animtils, such as caLs and dogs, have been known to suckle 

 young of other species, even when they had no progeny of 

 their own; and corresponding instances among women who 

 have fostered orphan children are on record in the 

 physiological journals. Nay, more than this, a case is 

 related by Humboldt of a man who became the wet nurse 

 to an infant child. " In the village of Arenas there lived 

 a labourer, Francisco Lozano, who had suckled a child. 

 Its mother happening to be sick, he took it, and, in order 

 to quiet it, pressed it to his breast, when the stimulus 

 imparted by the sucking of the child caused a flow of milk. 

 The man was examined by M. Bonpland, who found the 

 breasts wrinkled, like those of _ women who have nursed. 



