70 Mutability and individual Variation. 



Association in Oxford in 1894:^ The theory of selection 

 is by no means to be regarded as proven ; for a host of 

 difficulties stand in the way of the acceptance of the 

 explanation of evolution by the accumulation of ordi- 

 nary (individual) variations. And still more recently 

 Rosa,- from the standpoint of critical studies in phy- 

 logeny has insisted on the distinction between mutations 

 and fluctuations, considering only the first group as 

 phylogenetic variations. 



^Nature, Aug. 9, 1894. 



^D. Rosa, La ridii.zionc progressiva dcUa variabilita c i suoi 

 rapporti coll'estinaione et coU'originc dclle specie, Torino, C. Clau- 

 sen, 1899, P- 93- 



