EVOLUTION AND ITS CONSEQUENCES. 3 



planation of their " origin," as its author indeed freely allows. 

 Besides, the unscientific world is particularly unreasonable on 

 one point. Little knowing the slow steps and laborious effort by 

 which any general truth is reached, they find in incompleteness 

 ground of condemnation of the whole. Science is glad if she can 

 prove that the earth stands on an elephant, and gladder if she can 

 demonstrate that the elephant stands on a turtle ; but, if she can 

 not show the support of the turtle, she is not discouraged, but 

 labors patiently, trusting that the future of discovery will justify 

 the experience of the past. 



If, then, some of the people find Mr. Darwin's argument in- 

 complete, or in some points weak, it may be answered, so do the 

 student classes, who, nevertheless, believe it. This is largely be- 

 cause Darwin's facts and thoughts repeat a vast multiplicity of 

 experiences of every student, which are of as much significance 

 as those cited by him, and which only required a courageous 

 officer to marshal them into line, a mighty host, conquering and 

 to conquer. These will slowly find their way into print, some in 

 one country and some in another. 



I. THE FACT OF EVOLUTION. 



As to the truth of the theory, the proof has been stated in 

 more than one form. The first and simplest, and essentially the 

 central argument of Darwin, is as follows : 



In every family or larger group of animals and plants there 

 exists one or more genera in which the species present an aggre- 

 gation of specific intensity of form ; that is, that species become 

 more and more closely related, and finally varieties of single spe- j 

 eies have to be admitted for the sake of obtaining a systematic/ 

 definition or " diagnosis," which will apply to all the individuals. 

 These varieties are frequently as well marked as the nearly-related 

 species, so far as amount of difference is concerned, the distinc- 

 tion between the two cases being that in the varieties there is a 

 gradation from one to the other ; in the species, none. Neverthe- 

 less, T)eTween some of the varieti^ transitions mav be of rare oc- 

 currence, and in the case of the *' species " an intermediate indi- 

 vidual or two may occasionally be found. Thus it is that differ- 

 ences, called varietal and specific, are distinguished by degree 

 only, and not in kind, and are, therefore, the results of the opera- 

 tion of uniform laws. Yet, according to the old theory, the varie- 

 ties have a common origin, and the species an independent one ! 



