VARIATION 



51 



The habitats of the two lots were so near together, 

 however, that there was probably a considerable 

 intermixture of the two types, as shown by the 

 tendency of each polygon to produce a second mode. 



13 H 15 16 17 18 19 ZO 21 22 23 Z* 



26 11 28 Z9 SO 31 82 55 34 S 36 37 38 39 



FIG 



28. Variation in the ray florets of the white daisy (Chrysanthe- 

 mum leucanthemum) . A, from a swampy meadow. B, from a hillside 

 pasture near by. Both the polygons 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. 



Thus the A polygon shows that there is an increasing 

 tendency or variability in the twenty-one floret 

 type toward the thirty-four floret type, due probably 

 in this particular instance to invasion resulting 

 from the proximity of the B colony. 



