'(8) 



varieties in many characters seen in hogs and cattle, 

 especially when examples 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 con- 

 ditions 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 on 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 definable species cannot be 

 denied, especially in consideration of the following 

 facts : Protean species nearly always have a wide geo- 

 graphical distribution. They exist under more varied 

 circumstances than do individuals of a more restricted 

 species. The subordinate variations of the protean 

 species are generally, like the restricted species, con- 

 fined 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 mountain ranges, so have 

 vast numbers of individuals occupying such areas been 

 destroyed. Important alterations of temperature, or 

 great changes in abundance or character of vegetable 

 life over given areas, would produce the same result. 



This part of the subject might be prolonged, were it 



