Dv Morton on Hybrid Animals and Plants. 



The phenomenon of productiveness has little or no limit 

 among the true horses ; whence it has been inferred that they 

 all belong to one species ; and that their various forms and 

 colours are solely owing to the diversified circumstances in 

 tvhich they have been placed. But the researches of Hamil- 

 ton Smith, have not only given rise to much doubt on this 

 subject, but have adduced a surprising array of facts in fa- 

 vour of the opposite opinion. 



We must refer to his learned and elaborate essay for the 

 mass of evidence therein embodied ; merely observing, on the 

 present occasion, that he separates the horses into five pri- 

 mitive stocks, which appear to constitute " distinct, though 

 osculating species, or at least races separated at so remote a 

 period, that they claim to have been divided from the ear- 

 liest times of our present zoology."* 



He adds, that some of these forms yet exist in the wild 

 state on the table-lands of Central Asia, and that all of them 

 were so constituted as to be fusible into a common, specific, 

 but very variable stock, for the purposes of man ; and he 

 finally concludes, that if man had been necessitated to culti- 

 vate the zebras of South Africa, instead of the horses of Asia, 

 he would have succeeded in amalgamating the three or foiir 

 known species into one domestic animal, little inferior to the 

 horse itself, f 



It therefore becomes a reasonable supposition that some 

 varieties of the horse now known to us may be hybrid mix- 

 tures of proximate species : more especially, since the facts 

 collected by Hamilton Smith, De Azara, and De la Malle, 

 shew conclusively that all the domestic horses were reclaim- 

 ed from the original wild state. 



^ Natural History of the Equidae, p. 154. 



t Ibid., pj). 75, 183. Fossil remains of the horse, and especially the teeth, 

 have been of late years abundantly found in Europe and Asia, and in North 

 and South America, and especially near Natchez, by Dr Dickerson ; shewing 

 that this animal was once indigenous to all these widely extended regions ; and 

 yet there are now no horses in the Western Hemisphere, excepting those that 

 have descended from the European stock. The indigenous species must haviB 

 become extinct from some remote and extended cataclysm. It is curious also 

 to note that these fossil horses were different in species from the present variety, 

 although they were closely allied to it. There were in ancient times several, 

 perhaps many, species of the genus Equus. 



