THE MAMMALIA. 39 



followed. In the early days of Darwinism, evolutionists were 

 scornfully told to produce a five-toed ancestor of the horse. 

 Accustomed only to the narrow range of historical time, the oppo- 

 nents of evolution thought that because animals — such as the 

 horse, the bull, and the cat — were the same in old pictured 

 inscriptions as they are now, that, therefore, they must have been 

 originally created just as we see them. 



We will briefly give the pedigree of the horse. As it is the 

 most perfect and curious of animal pedigrees, so it is also the 

 most widely known. In the Lower Eocene of New Mexico are 

 found the remains of Eohippus, an animal about the size of a 

 fox, which had the full number of teeth (44) and a rudirtientary 

 thumb, besides four toes on its fore feet. The hind feet had three 

 toes, and all the digits terminated in hoofs. 



In beds rather higher than those containing Eohippiis, Orohip- 

 pus is found. It was of about the same size as Eohippiis, and 

 possessed four toes on the fore feet and three toes on the hind 

 feet ; but the third digit is the largest, and the rudimentary thumb 

 has disappeared. It has still 44 teeth, but a long interval sepa- 

 rates the premolars from the canines, a peculiarity which still 

 more strongly characterises the modern horse. 



In the Lower Miocene, Mesohippiis appears, an animal about 

 as large as a sheep, but with longer legs. The fore feet are now 

 three-toed, and a " splint-bone " only remains to represent the 

 little finger. Anchitheriuni, of the European Miocene, represents 

 one step further in advance. There were three toes which reached 

 the ground on each foot, but the middle one was the largest, and 

 even the splint-bone representing the fifth toe had disappeared. 



In late Miocene and early Pliocene times, a much more dis- 

 tinctly horse-like form makes its appearance, though the anatomical 

 differences between Hipparion and its predecessor are not great. 

 The central toe (third digit) is now the only toe which touches the 

 ground, whilst the second and fourth digits, though visible exter- 

 nally and furnished with small hoofs, are so much reduced in size 

 as to_^take no part in supporting the weight of the body. 



Finally appears the true horse, in which the useless second and 

 fourth digits of Hipparion are reduced to "splint-bones," con- 

 cealed beneath the skin. 



