230 ZOOLOGICAL ACCEPTATION OF 



instance, the cliipans^ of angola and the orang-utang of 

 Borneo ? Nor are- there so many doubts about these, as 

 about the domesticated animals, which are thus excluded. 



The different breeds of dogs, for example, are referred by 

 some to different species ; and they are indeed sufficiently 

 marked by distinctive permanent characters to warrant the 

 opinion, if the constancy of such characters were a suffi- 

 cient proof of difference in species. Others, again, refer 

 them all to the shepherd's dog ; and others include all the 

 dogs, the wolf, fox, and jackall, in one species. The dog 

 and bitch produce with the male and female wolf, and with 

 the dog and bitch fox; and the offspring is prolific. Yet 

 we cannot surely ascribe animals, which are marked in their 

 wild state by such strong characters, of bodily formation, 

 disposition, and habits— as the wolf, fox, and jackall, to one 

 and the same species, without overturning all the funda- 

 mental principles of zoology, however freely they may inter- 

 mix, and however perfect the reproductive power may be in 

 their offspring *. 



We may conclude, then, from a general review of the pre- 

 ceding facts, that nature has provided, by the insurmount- 

 able barriers of instinctive aversion, of sterility in the hybrid 

 offspring, and in the allotment of species to different parts 

 of the earth, against any corruption or change of species in 



* Pallas entertains the opinion that our sheep, dogs, and perhaps poultry, 

 are factitious beings, not descended from any single wild original, but from a 

 mixture of nearly-allied primitive species, whose hybrid ofl'springs have pos- 

 sessed prolific powers. He observes that those domesticated animals, which 

 either do not intermix with other species, or which produce with others 

 unprolific progeny, are very little changed, however completely and anciently 

 they may have been brought under the dominion of man ; or at least are not 

 so changed as to cause any difficulty respecting their origin. This is the case 

 with the horse and ass in all climates ; with the ox kind ; with the pig ; the 

 camel and dromedary; and the rein-deer. He refers our sheep to intermix- 

 tures of the Siberian argali (ovis ammon), the mouflon of Corsica and Sar- 

 dinia, that of Africa, (ovis tragelaphus Cuv.),the wild goat of Persia (pa- 

 seng, the bezoar animal, capra aegagrus), the bouquetin (capra ibex), and 

 the wild goat of Caucasus (capra Caucasica), The dog he considers to 

 have proceeded from the jackal, wolf, and fox. — Mcmoire sur la Variation 

 dcs Jnimaux ', Acta Acad* Petrop. 17S0. 



