THE FRAGRAXT CALLA 21 



developed in the past are still in operation every- 

 where about us. Many people are disposed to 

 think of natural selection as a principle referring 

 to past times and to the development of organ- 

 isms long since perfected. 



In point of fact past times are like present 

 times in the operation of their laws. The re- 

 actions between organism and environment are 

 now what they always were. No race is perfected, 

 no organism freed from the struggle for exis- 

 tence; although, of course, under the conditions 

 of civilization the operation of "natural selection" 

 may be modified through man's influence, and the 

 conditions of life for a given organism radically 

 changed by artificial selection. 



EVOLUTION THROUGH MUTATION 



But let us not forget our theme. With the 

 case of the fragrant calla to furnish our text, I 

 was about to speak of those variations from the 

 normal on the part of any given organism which 

 lie outside the ordinary range of variation and 

 which therefore constitute so definite and pro- 

 nounced a departure that they have long been 

 spoken of as "sports." 



To these some of the present-day evolutionists, 

 following Professor Hugo de Vries, give the 

 name of "mutations." 



