172 THE BREEDING OF ANIMALS 



horse foal; twenty mares gave birth to four mule foals 

 each, followed by a horse foal; eight mares gave birth 

 to five foals each, and later to horse foals; ten mares 

 observed produced six mule foals each, and afterward 

 gave birth to horse foals; seven mares produced seven 

 mule foals followed by horse foals; five mares produced 

 horse foals after having foaled eight mules each, two mares 

 dropped ten mules each, followed by horse foals; while 

 one mare produced ten mule foals and then a horse foal 

 and one mare was bred to a stallion and produced a healthy 

 horse foal after having given birth to thirteen mule foals 

 in succession. 



161. Example of horse foals. The horse foals from 

 these mares were carefully examined and measured for 

 the purpose of discovering any possible resemblances 

 to the previous jack sire from which mules had been 

 produced. The chief external characters which dis- 

 tinguish the mule from the horse are the size and form of 

 the ears, head, feet, legs, body, mane, tail, disposition and 

 voice. 



The illustrations of dams and offspring give a fairly 

 adequate idea of the generally uniform nature of the 

 results which were found throughout the investigation. 



In Plate X, lower, is shown the yearling offspring of a 

 mare (Plate X, upper) that had previously produced seven 

 mule foals and then gave birth to the animal shown in the 

 illustration. A careful examination of the characters in 

 which mules and horses differ showed that the offspring 

 in this case had small, rather short, smooth head, small, 

 short, pointed ears, a broad flat foot and rather broad 

 hips and loins, with a well-rounded body. None of the 

 characters of this yearling colt suggested in the slightest 

 degree any evidence that it had been influenced by the 



