Dr Morton on Hybrid Animals and Plants. 265 



mule and the mare, which appears to have been a common 

 animal among the Romans, who called it also the Little Mule, 

 (Tarvum mulum.)'^ 



Prevost and Dumas, repeating the experiments of Lieuen- 

 hoeck, assure us that the sterility of these mules in northern 

 climates depends on an absence of spermatic animalcules ; 

 but the latter must be present in hot countries, to explain 

 the phenomena of reproduction. 



The Hinny, on the other hand, is the offspring of the horse 

 and a female ass — Bardo ex equo et assind — an animal of a 

 very refractory disposition, and little esteemed, either in an- 

 cient or modern times ; nor have I been able to obtain any 

 facts in relation to its reproductiveness. 



Again, when a male, derived from the cross " between the 

 she ass and the male onager {Equus onayer), is allowed to 

 couple with the mare, the offspring is more docile than either 

 parent, and unites the beauty of form and gentle disposition 

 of the father with the strength and swiftness of his grand- 

 sire ;t whence the ancients preferred the onager to the ass 

 for the production of mules, and Mr Gliddon informs me that 

 this opinion is prevalent in Egypt at the present day. 



The Baron Cuvier informs us that he had seen the cross 

 between the ass and zebra, and between the female zebra 

 and horse. J 



The ass is not the proximate species of the genus Equus, 

 when compared with the horse ; but that place is held, as 

 Cuvier remarks, by the Bziggetai of Asia (^Eq. heinionus.) And 

 two distinguished naturalists, Mr Bell and Mr Gray, are even 

 disposed to remove the ass to a separate genus. Without 

 passing judgment on this question, I will merely observe, 

 that in order to obtain a prolific breed of hybrid horses, the 

 true horse should be coupled with the hemionus, under the 

 same adaptation of climate and domesticity that have been 

 bestowed on some other mixed animals ; nor until this expe- 

 riment has been fairly tried, can we speak with absolute cer- 

 tainty of the extent of productiveness of equine mules. 



* M. de la Malle, Ann. des Sciences Nat. xxvii., p. 143. 

 t Columella, quoted ut sitpra, p. 135. 

 X Regne Animal, p. 182. 

 VOL. XLIII. NO. LXXXVI. — OCTOBER 1847- S 



