NATURAL HISTORY. 161 



*peak, are small in their size, and have, like assts, the 

 voat grey, and the tail naked and frizzled at the end. 

 They also mention wild horses, arid even domestic ones, 

 \vhich have a black stripe on the back, and other marks 

 which nearly resemble both wild and domestic asses. 



Again, if we consider the difference of the temper- 

 ament, disposition, the manners, the organism, of 

 these two animals, and, above all, the impossibility of 

 mixing the breed to make one common species, or even 

 an intermediate species which may be renewed, it ap- 

 pears a better-founded opinion, to think that these ani- 

 mals are of a species equally ancient, and originally 

 as different as they are at present. The ass differ* 

 materially from the horse, in the smallness of the size, 

 largeness of the head, length of the ears, hardness of 

 the skin, nakedness of the tail, the form of the rump, 

 and also in the dimensions of the neighbouring parts ; 

 such as the voice, the appetite, manner of drinking, &c. 

 Do the horse and the ass, then, come originally from 

 the same stock ? are they of the same family, or not f 

 and have they not always been different animals ? 



When two individuals cannot produce together, we 

 can no otherwise account for it, but from a slight dif- 

 ference in their temperament, or some accidental fault 

 in the organs of generation, of one or other of these 

 two individuals. That two individuals of different 

 species, should produce other individuals which do not 

 resemble the one or the other in any fixed particular, 

 and can consequently produce nothing like themselves, 

 there needs but a certain degree of conformity between 

 the form of the body and the organs of generation of 

 these different animals. But what an immense num- 

 ber of combinations are necessary, even to suppose 

 that two animals, male and female, of a certain spe- 



VoLL U 



