HORSES. 135 



that not only all these supposed species belonged to one and the same, but that that one was the 

 common domestic Horse. 



The occurrence of distinct species in America is very interesting, considering their subsequent 

 extinction, and the rehabilitation of the common species by man both in South and North America. 

 More than one sj^ecies has been described, but at least one lived, both in North and South America. 

 The first trace of it was discovered by Darwin. In his " Journal of a Naturalist," he mentions having 

 discovered, in the Pampean deposit at Bajada, one tooth of a Horse in the same stained and decayed 

 state as the remains of a Mastodon and Toxodon, as well as of a gigantic armadillo-like animal. 

 This tooth greatly interested him, for it was well established that no Horse was living in America 

 at the time of Columbus, and no remains of any had previously been found ; and he was not then 

 aware that amongst some other fossils which he had himself procured at Bahia Blanca, there was 

 a Horse's tooth in the matrix ; nor was it then known that the remains of Horses are common in 

 North America. Mr. Lyell (now Sir Charles) had, however, then latelj' brought from the United 

 States a tooth of a Horse ; and it is an interesting fact, that Prof. Owen could find in no species, 

 either fossil or recent, a slight but peculiar curvature characterizing it, until he thought of com- 

 paring it with Mr. Darwin's specimen from the Pampas, — when he found the two to correspond. 

 He named this American Horse Equus curvidexs. Certainly, as Mr. Darwin says, it is a mar- 

 vellous fact in the history of the Mammalia, that in South America a native Horse shoidd have 

 lived and disappeared, to be succeeded in after ages by countless herds, descended from the few 

 introduced by the Spanish colonists. 



Certainly it is so ; but that is not the only noteworthy thing about it. It is remarkable that 

 it should be found in North America, and is one of the proofs that there must not always have 

 been such a barrier against the mutual intercommunication of species north and south of Mexico 

 as appears to have at one time existed. The history of the species interred in the Mauvaiscs 

 Torres cemetery have already taught us to expect this, and tlie Horse is only one of many other 

 instances proving it. 



Another curious fact, looking to the South American habitat of the Equus curvidexs, is, that 

 the nearest existing species to it, after the domestic Horse, is the Quagga, which inhabits the 

 most southern parts of South Africa. More than one instance of affinity between species found in 

 the south of South America and the Cape of Good Hope, have already made us think of how 

 the space between them could be best bridged over. 



In addition to the Equus curvidens above mentioned, there is an E. Americanus, and Lund 

 discovered in the caverns of Brazil remains of two species, E. principalis and E. xeogeus, and 

 a doubt fvd one. 



The number of the living sjsccies of this family is very limited. Besides the domestic Horse 

 Giebel allows only five species ; but Mr. Edward Blyth, who has paid much attention to the family, 

 gives pretty strong arguments for admitting seven,* besides the domestic Horse. "Without going 

 into the grounds on which he rests his opinions, I shall simply recapitulate the results at which 

 he has arrived, and the limits which he assigns to the range of each, adding another species not 

 noticed by him, which was discovered b}' Henglin in Abyssinia. 



1. Equus Quagga. The Quagga from Soiith Africa, scarcely found northwards of the Gariep 

 or Orange river ; but still in great herds southwards, nssociatiug with the white-tailed Gnu, as 



* Blttii, fa., " On the diffcrout animals known as Wild Asses," iu " Journal of Asiatic Sociuty," vol. 28, ISGO, p. 229. 



