THE STOR\f OF NINETEENTH-CENTURY SCIENCE 



last the suspicion long harbored grew into a settled con- 

 viction that there is really no such thing as a species of 

 organism in nature ; that " species " is a tigment of the 



human imagination, whereas in nature there are only 

 individuals. 



That certain sets of individuals are more like one an- 

 other than like other sets is of course patent, but this 



294 



