260 Evolution and Adaptation 



of disuse are inherited. There is, however, no proof that 

 this is the case, although there are a number of instances to 

 which this mode of explanation appears to give the readiest 

 solution. But, as has been said before, it is not this kind 

 of evidence that the theory is in need of, since Lamarck him- 

 self gave an ample supply of illustrations. What we need is 

 clear evidence that this sort of inheritance is possible, and, 

 from the very nature of the case, it is just this evidence that 

 fossil remains can never supply. 



The same criticism may be made of the work of Ryder, 

 Packard, Dall, Jackson, Eimer, Cunningham, Semper, De 

 Varigny, and others of the Lamarckian school. Despite the 

 large number of cases that they have collected, which appear 

 to them to be most easily explained on the assumption of 

 the inheritance of acquired characters, the proof that such 

 inheritance is possible is not forthcoming. Why not then 

 spend a small part of the energy, that has been used to 

 expound the theory, in demonstrating that such a thing is 

 really possible ? One of the chief virtues of the Lamarckian 

 theory is that it is capable of experimental verification or con- 

 tradiction, and who can be expected to furnish such proof if 

 not the Neo-Lamarckians ? 



We may fairly sum up our position in regard to the theory 

 of the inheritance of acquired characters in the verdict of 

 "not proven." I am not sure that we should not be justified 

 at present in claiming that the theory is unnecessary and 

 even improbable. 



