VARIATION AND HEREDITY 121 



ance, being anything but liable to swamping; 

 and (3) that we have not, even to this day, 

 sufficient knowledge of what Darwin never 

 seems to have doubted, namely the degree of 

 heritability of the minute fluctuations. It 

 was probably a false step on Darwin's part 

 when he turned so fully away from discon- 

 tinuous variations. 



MODERN STUDY OF VARIATIONS. One of 

 the great steps of progress in evolution lore 

 since Darwin's day has been what we see, for 

 instance, in Dr. J. A. Allen's pioneer measure- 

 ments of American birds (1871), in Bateson's 

 " Materials for the Study of Variation " (1894), 

 and in the pages of the journal called " Biome- 

 trika " the recording and registration of the 

 variations that do actually occur in nature. 

 A few results may be noted. 



It has been clearly shown that Darwin did 

 not in the least exaggerate the available 

 supply of raw material. " Even Darwin 

 himself," as Wallace says, " did not realize 

 how much and how universally wild species 

 vary." It has been proved that great varia- 

 tion is as frequent in wild as in domesticated 

 animals. The fountain of change is even more 

 copious than was dreamed of. 



Another important fact has come out clearly, 

 especially from the pioneering work of Galton, 



