(7) IS' 



observe in defining species is a clear consequence of 

 such a state of things. It is not amount and degree of 

 difference that determine the definition of species from 

 species, but it is the permanency of the characters in all 

 cases and under all circumstances. Many species of 

 the systems include varieties and extremes of form, etc., 

 which, were they at all times distinct, and not connected 

 by intermediate forms, would be estimated as species by 

 the same and other writers, as can be easily seen by 

 reference to their works. 



Thus, species are either "restricted" or "protean," 

 the latter embracing many, the former few variations ; 

 and the varieties included by the protean species are 

 often as different from each other in their typical forms 

 as are the " restricted " species. As an example, the 

 species Homo sapiens (man) will suffice. His primary 

 varieties are as distinct as the species of many well 

 known genera, but cannot be defined, owing to the ex- 

 istence of innumerable intermediate forms between 

 them. 



As to the common origin of such "varieties" of the 

 protean species, naturalists never had any doubt, yet 

 when it comes to the restricted " species," the anti-de- 

 velopmentalist denies it in 1oto. Thus the varieties of 

 most of the domesticated animals are some of them 

 known others held with great probability to have had a 

 common origin. Varieties of plumage in fowls and 

 canaries are of every-day occurrence, and are produced 

 under our eyes. The cart-horse and racer, the Shet- 

 land pony and the Norman, are without doubt derived 

 from the same parentage. The varieties of pigeons and 

 ducks are of the same kind, but not every one is aware 

 of the extent and amount of such variations. The 



