442 THE WHITE CHINA GOOSE. 



aptitude for domestication has preserved the race: they sur- 

 vive in our poultry-yards, artificial lakes, and Zoological Gar- 

 dens,* and, after a while, they are styled varieties of, nobody 

 indeed knows what. If they had refused to propogate in cap- 

 tivity, they would have become extinct, like the Uri of the 

 Hercynian forest.f 



Is this an impossible or even an unlikely case ? Where are 

 we now to find a wild Cereopsis ? Where will our great-grand- 

 children be able to find a Wild Turkey a hundred years 

 hence ? 



But before finally determining to fix the appellation of 

 species, or variety, to any particular race of animals, it will be 

 necessary first to settle the question of what is meant by the 

 terms Genus, Species, and Variety. They are all understood 

 to denote certain degrees of difference, that are made use of 

 to assist in classification ; but the precise lines of demarcation 

 of each are extremely difficult to define. It is generally as- 

 sumed that individuals of different genera will refuse to breed 

 together ; that the mules between different species are sterile ; 

 and that varieties are merely accidental and recent examples 

 of a slight alteration in the external character of species, 

 which do not affect their continuance as a race, and, perhaps, 

 disappear altogether after a time. But in opposition to this, 

 hybrids have been produced between the Egyptian Goose and 

 the Penguin Duck ; also between the Common Fowl and the 



* " The forethought and industry of Man assists in the preserva- 

 tion and safety of not a few animals, and those things which the 

 earth produces. For there are many, both of beasts and plants, that 

 could not continue in existence, if deprived of the protection of 

 Man." CICERO, De Naturd JDeorum II. 



f " But not even when taken very small, can the Uri be reconciled 

 to the presence of man, and become tame." CAESAR de Bello Gallice, 

 lib. ii. cap. 28. 



