GENETICS 



distant. Among these two lots of daisies the number 

 of ray florets varies from twelve to thirty-eight and 

 their frequency polygons, as shown in Figure 8, form 

 what are termed "skew curves," because the mode in 



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 FIG. 8. Variation in the ray florets of the white daisy (Chrysan- 

 themum leucanthemum) . A, from a swampy meadow. JB, 

 from a dry hillside pasture near by. Both the curves are 

 "skew" because in each case there is an admixture of the 

 other type. The distinction between the two types is due to 

 heredity rather than to environment. 



each case lies considerably to one side of the arith- 

 metical mean. 



It will be seen that lot A from the swampy meadow, 

 which in spite of the greater fertility of the soil and 

 the unquestionably greater luxuriance of the plants 

 themselves, produced heads with fewer florets, fluctu- 



