VARIATION AND HEREDITY 119 



racial importance of modifications, it is of 

 interest to notice Darwin's view of the 

 relative importance of "Dingle variations" 

 and "individual variations." The_ former 

 correspond in a general way Jco what we 

 now call " rfomntiniioiis yaf iaffi cms." "jnuta- 



the latter o 



continuous variations" or "fluctuations." 

 Darwin was much interested in the former 

 class, "sports" as he sometimes called them; 

 but true to the influence of Lyell he came 

 deliberately to the conclusion that the minute 

 ubiquitous fluctuations were by far the more 

 important. The criticism of Fleeming Jen- 

 kin, Professor of Engineering in Edinburgh, 

 that single large peculiarities wouIdJae likely 

 to be swamped by inter-crossing, 

 much weight with i D^r^n . tfrat 

 attach Importanceja^thejg^jg^r . 

 and found his raw material in the smaller 

 fluctuations. "The more I work," he said, 

 "the more I feel convinced it is 

 r.,m,,Ution of ^m^ rHn^nlTf rH 



tjpr|g t^ 1 ^ Tif^w &p pp i p ^ fl.rigp.** \Ve shall 

 return to this question, but we may note in 

 passing (1} that there is no reason to hpJievft 

 J:hat "sin^Ie^vafi^infisil ^ftf^ssarjly occur 

 gingly, the fact being that numerous sports 

 TiTtEe same direction sometimes occur simul- 

 taneously; (2) that some of tfr** 



