7 8 ORGANIC EVOLUTION 



fertile females retaining their special instincts of nest-build- 

 ing and caring for the young. These activities might then 

 be left wholly to the neuter workers, which would give us 

 the condition found among the bees at present. It seems 

 not improbable that this has been the general course of the 

 development of the instincts of the worker-bees. I have 

 given Weismann's argument because it is one so often 

 quoted, though it is not conclusive. There are, however, 

 many classes of phenomena whose development can be ex- 

 plained by natural selection but not by the inheritance of 

 parental modifications, and these phenomena are as remark- 

 able as any we have to explain. We do not need the hypoth- 

 esis of the inheritance of parental modifications to explain 

 nature because of natural phenomena being " too wonderful 

 for any other explanation." 



Finally, the inheritance of parental modifications, even 

 if it occurred, would be wholly inadequate to explain the 

 most fundamental feature of the phenomena of organic 

 nature ; namely, the adaptation of the organism to its 

 environment. Adaptation is the key-note of organic nature, 

 and it is exactly the thing natural selection secures, for those 

 individuals which are not adapted to their environment are 

 destroyed in the struggle for existence, leaving only the well- 

 adapted forms alive. The inheritance of parental modifica- 

 tions, on the other hand, could not produce adaptation to the 

 environment, unless the influence of the environment upon 

 each individual organism and the reaction of the organism 

 itself were such as to produce adaptation of each individual 

 to its environment, and we are far from having sufficient 

 evidence that the direct changes produced in each individual 

 by the influence of the environment are thus adaptive. For 



