770 THE POPULAR SCIEXCE MONTHLY. 



in some way, the reproductive elements : these being found to evolve 

 unusual structures when the constitutional balance has been continu- 

 ously disturbed. 3. But the changes in the reproductive 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. 



" But where are the direct proofs that inheritance of functionally- 

 produced modifications takes place ? " is a question which will be put 

 by those who have committed themselves to the current exclusive in- 

 terpretation. " Grant that there are difficulties ; still, before the trans- 

 mitted effects of use and disuse can be legitimately assigned in expla- 

 nation of them, we must have good evidence that the effects of use 

 and disuse are transmitted." 



Before dealing directly with this demurrer, let me deal with it 

 indirectly, by pointing out that the lack of recognized evidence may 

 be accounted for without assuming that there is not plenty of it. In- 

 attention and reluctant attention lead to the ignoring of facts which 

 really exist in abundance ; as is well illustrated in the case of pre-his- 

 toric implements. Biassed by the current belief that no traces of man 

 were to be found on the Earth's surface, save in certain superficial 

 formations of very recent date, geologists and anthropologists not 

 only neglected to seek such traces, but for a long time continued to 

 pooh-pooh those who said they had found them. When M. Boucher 

 de Perthes at length succeeded in drawing the eyes of scientific men 

 to the flint implements discovered by him in the quaternary deposits 

 of the Somme valley ; and when geologists and anthropologists had 

 thus been convinced that evidences of human existence were to be 

 found in formations of considerable age, and thereafter began to search 

 for them ; they found plenty of them all over the world. Or again, 

 to take an instance closely germane to the matter, we may recall the 

 fact that the contemptuous attitude toward the hypothesis of organic 

 evolution which naturalists in general maintained before the publica- 

 tion of Mr. Darwin's Avork, prevented them from seeing the multitu- 

 dinous facts by which it is supported. Similarly, it is very possible 

 that their alienation from the belief that there is a transmission of 

 those changes of structure which are produced by changes of action, 

 makes naturalists slight the evidence which supports that belief and 

 refuse to occupy themselves in seeking further evidence. 



