24 THE FACTORS OF ORGANIC EVOLUTION. 



before all the many required re-adjustments could be made, 

 the variety would die out from defective constitution. 

 Even were there no such difficulty, we should still have to 

 entertain a strange group of propositions, which would 

 stand as follows : 1. Change in one part entails, by 

 reaction on the organism, changes, in other parts, the func 

 tions of which are necessarily changed. 2. Such changes 

 worked in the individual, affect, in some way, the repro 

 ductive elements : these being found to evolve unusual 

 structures when the constitutional balance has been con 

 tinuously disturbed. 3. But the changes in the reproduc 

 tive elements thus caused, are not such as represent these 

 functionally-produced changes : the modifications conveyed 

 to offspring are irrelevant to these various modifications 

 functionally produced in the organs of the parents. 4. 

 Nevertheless, while the balance of functions cannot be re 

 established through inheritance of the effects of disturbed 

 functions on structures, wrought throughout the individual 

 organism; it can be re-established by the inheritance 

 of fortuitous variations which occur in all the affected 

 organs without reference to these changes of function. 



Now without saying that acceptance of this group of 

 propositions is impossible, we may certainly say that it is 

 not easy. 



&quot; But where are the direct proofs that inheritance of 

 functionally-produced modifications takes place?&quot; is a 

 question which will be put by those who have committed 

 themselves to the current exclusive interpretation. &quot; Grant 

 that there are difficulties ; still, before the transmitted 

 effects of use and disuse can be legitimately assigned in 

 explanation of them, we must have good evidence that the 

 effects of use and disuse are transmitted.&quot; 



Before dealing directly with this demurrer, let me deal 

 with it indirectly, by pointing out that the lack of recog 

 nized evidence may be accounted for without assuming 



