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HISTORY OF MEXICO. 



uncertainty of it, let us put an afs and a mare together, 

 and a maftiff and a greyhound together, two breeds of 

 dogs extremely different. From this laft couple is bred 

 a dog, which partakes of maftiff and greyhound ; from 

 the firfl is produced a mule, which partakes alfo of the 

 afs and the mare. I wifh to know why the afs and the 

 mare are two different fpecies of quadrupeds, and the 

 maftiff and the greyhound are only varieties of one fpe- 

 cies. Becaufe this laft couple, fays Buffon, generates a 

 fruitful individual, the other not. But how ? Mr. Buf- 

 fon in the twenty-ninth volume of his Hiftory, freely 

 affirms, that the mules not being able to conceive is not 

 becaufe they are abfolutely impotent, but only on ac- 

 count of the exceffive heat and extraordinary convulfions 

 which they fuffer in coition. Mr. Bomare (<:), after 

 having cited the teftimony of Ariftotle, who reports, in 

 his Hiftory of Animals, that in his time the mules of 

 Syria fpringing from horfes and affes, produced young 

 mules fimilar to themfelves, adds, " This fac~t, related 

 by a philofopher fo worthy of faith, proves that mules 

 are animals fpecifically fruitful in themfelves, and in their 

 pofterity." Similar cafes, fhewing the fruitfulnefs of 

 mules, are to be found attefted by many authors, anci- 

 ent as well as modern, worthy of credit ; and fome cafes 

 have happened of this kind in our own time in Mexico 

 (d). There is no other diftimilarity therefore between 

 thofe two pair of quadrupeds, except that the births of 

 the bitches generated by that couple of dogs are more 

 frequent than thofe of the mules. 



Befides 



(c) Di&ion. d' Hiftoire Nat. V. Mulct. 



(J) Amongft others worthy of mention are the repeated births of a mule 

 got by an afs and a mare, on the farm called Forejl of Zurita, near to the city 

 of Lagos, the property of D. F. G. Rubalcaba. This mule conceived by an 

 afs, and brought forth a mule in 176a, and another in 1763. 



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