THE CAMELS. 155 



as belonging to one another. Of the two species of 

 camels the one with two humps is assigned to Cen- 

 tral Asia; the other has been distributed over a 

 large portion of Africa by Asiatic nomads, and 

 represents a peculiar mode of life. The llama 

 'vicariates' for them. The hoofs are small, but 

 the foot has a broad horny sole ; the skeleton of 

 the foot is that of a true Ruminant. The camels 

 differ from all the living Ruminants by the total 

 absence of horns and by a fuller dentition ; for 

 they not only possess strong sharp canines, but an 

 incisor in the mid jaw-bone, somewhat to the side. 

 All the other Ruminants, without exception, have 

 lost their upper incisors. On this account, and 

 because of the superficial resemblance in the form 

 of the skull with that of the horse, camels were 

 formerly classed as a group standing midway be- 

 tween the horses and the two-hoofed animals ; this, 

 however, is an unwarrantable conjecture. American 

 investigators have, on the other hand, now made 

 us acquainted with a w T hole series of primeval 

 forms, according to which the camel appears to be 

 a very old branch of the Selenodonts. 



Marsh gives us the result of his own and of 

 Leidy's observations thus : * A most interesting 

 line, that leading to the camels and llamas, sepa- 



