CHAPTER X 



EFFECTS OF ENVIRONMENT 



Let us give further attention to life in its primitive cell 

 organization. We have available for examination, descrip- 

 tions of natural processes, made by expert scientific men, 

 and these are more enlightening than our own research 

 would be. They show among other facts that there are 

 still living a great number of single-celled creatures, some 

 animal, some vegetable, some of a simplicity not describable 

 as either; and that they all have definable characteristics 

 which have heredity of a certain degree of constancy. Geo- 

 logical observation provoked the interesting question; are 

 these new creatures now in process of evolution, or are they 

 old, of types fixed, in a heredity which keeps them to, or 

 near to, constancy. If they are old and are evolving, so that 

 they are to be the elaborated higher animals and plants of 

 future time, how is it that they have not proceeded farther 

 on that course? Part of the answer is immediate. It can- 

 not be doubted that they are in process of evolution. Nothing 

 in nature is fixed. These creatures are the most responsive 

 of all, to environment, which is the evolution impulse. The 

 methods of modern germ culture, by which some of the 

 bacteria are deprived of their dangerous character, prove 

 this. That notable change is brought about by a change of 



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