NINTH LECTURE. 



SOME GOVERNING FACTORS USUALLY 



NEGLECTED IN BIOLOGICAL 



INVESTIGATIONS. 



ALPHEUS HYATT. 



THE object of this lecture will be fully attained if, by 

 fragmentary statements, I can attract the attention of my 

 audience to certain neglected or little understood facts and 

 theories. 



There will be no attempt to prove any special theory, but 

 simply to make statements and refer interested readers, if I am 

 so fortunate as to have any, to works in which more extended 

 information can be found. 



The terminology used in the following pages has been found 

 necessary to express more exact ideas of the relations of phe- 

 nomena which cannot be accurately described without such 

 aids. An old term used in a new sense is confusing, because 

 the accepted usage invariably clings to the word in the minds 

 of all but the inventor of the new meaning. 



It may seem useless to dwell on that familiar word " evolu- 

 tion," but, as a matter of fact, misconceptions of the true 

 meaning of this term are by no means rare, and a correct point 

 of view is necessary, especially in considering the relations of 

 ontogeny and phylogeny. 



Evolution is essentially continuity of matter moving through 

 time and space, and actually changing as it moves. The laws 

 of evolution are concise descriptive expressions of the modes 

 in which these movements and changes have taken place. The 

 causes of evolution and of the* accompanying changes are still 



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