Evolution: The Quest of Truth 149 



species may spring off from another species or 

 rise out of variations from it, the parent species 

 usually retaining its identity. 



Most of the groups of animals and plants 

 that are definite enough to be readily described 

 as species have probably practically completed 

 their general evolution ; they may not be able, 

 even, to give rise to other marked forms. The 

 world now contains species representing various 

 grades in the process of evolution ; but it is to 

 be supposed, since the earth is now relatively 

 stable and densely inhabited, that the progress 

 of the creation is at present comparatively 

 small. 



Evolution in operation. 



The opponents of the evolution philosophy 

 are always asking that the evolutionist show' 

 them the process in operation ; and at the same 

 time they are very likely to beg the question 

 by affirming that animals and plants are not 

 now changing. This latter position is strongly 

 maintained by the antagonist whom I have 

 been quoting : 



