ON THE HYPOTHESIS OF EVOLUTION. 131 



embracing many, the former few variations ; and the varieties in- 

 cluded by the protean species are often as different from each other 

 in their typical forms as are the ** restricted" species. As an ex- 

 ample, the species Homo sapiens (man) will suffice. His primary 

 varieties are as distinct as the species of many well-known genera, 

 but can not be defined, owing to the existence of innumerable in- 

 termediate 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-developmentalist denies it in toto. 

 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 Shetland 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 varieties 

 in many characters seen in hogs and cattle, especially when exam- 

 ples from distant countries are compared, are very striking, and 

 are confessedly equal in degree to those found to define species in 

 a state of nature : here, however, they are not definitive. 



It is easy to see that all that is necessary to produce in the 

 mind of the anti-developmentalist the illusion of distinct origin 

 by creation of many of these forms would be to destroy a number 

 of the intermediate conditions of specific form and structure, and 

 thus to leave remaining definable groups of individuals, and there- 

 fore "species." 



That such destructions and extinctions have been going no 

 ever since the existence of life on the globe is well known. That 

 it should affect intermediate forms, such as bind together the 

 types of a protean species as well as restricted species, is equally 

 certain. That its result has been to produce definaUe species can 

 not be denied, especially in consideration of the following facts : 

 Protean species nearly always have a wide geographical distribu- 

 tion. Thev exist under more varied circumstances than do indi- 

 viduals of a more restricted species. The subordinate variations 

 of the protean species are generally, like the restricted species, 

 confined to distinct subdivisions of the geographical area which 

 the whole occupies. As in geological time changes of level have 

 separated areas once continuous by bodies of water or high mount- 



