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THE AMERICAN NATURALIST [Vol. XLVI1I 



are now called (1) fluctuations or " non-inherited" (in reality, I 

 think, partially inherited) continuous variations; (2) instability 

 resulting from a heterozygous or partially heterozygous condi- 

 tion; (3) reversions, now believed to result chiefly from cross- 

 ing; and (4) mutations. 



Galton is equally explicit in other statements on this subject. 

 Like Darwin, he admitted the facts both of continuity and dis- 

 continuity in variation; but, unlike Darwin, he also recognized 

 discontinuity or alternation as well as continuity or blending, in 

 inheritance. Thus he says, in a paragraph headed "stability of 



Experience does not show that those wide varieties which are called 

 " sports " are unstable. On the contrary, they are often transmitted to 

 successive general ions with curious persistence. Neither is there any 

 reason for expecting otherwise. While we can well understand that a 

 strained modification of a type would not be so stable as one that ap- 

 proximates more nearly to the typical center, the variety may be so wide 

 that it falls into different conditions of stability, and ceases to be a 

 strained modification of the original type. 



In another paragraph, 3 headed "Evolution not by minute 

 steps only," he says: 



The theory of evolution might dispense with a restriction, for which 

 it is difficult to see either the need or the justification, namely, that the 

 course of evolution always proceeds by steps that are severally minute, 

 and that become effective only through accumulation. That the steps 

 may be small and that they must be small are very different views; it is 

 only to the latter that I object. ... An apparent ground for the com- 



termediate forms between widely divergent varieties, whether they be of 

 plants or of animals, of weapons or utensils, of customs, religion or 

 language, or of any other product of evolution, a long and orderly series 



perceptible degree from the adjacent specimens. But it does not at all 



they are the very stages that were passed through in the course of evo- 

 lution. Counter evidence exists in abundance, not only of the appear- 

 ance of considerable sports, but of their remarkable stability in hered- 



Again, Galton not only believed in the existence of both 

 blended and alternative inheritance, but he recognized the im- 



2 L. c, p. 30. 



3 L. c, p. 32. 



