QUETELET'S LAW 



517 



greatest number of plants is taken as the standard or type. 

 (Students of variations commonly call this most usual number the 

 mode. Around this most usual number the other numbers 

 fluctuate both above and below, and the more any number of 

 kernels per head differs from the usual number, the fewer the 

 plants having that number until finally a limit both above and 

 below the type is reached. In other words, small divergencies 

 from the type are numerous, while larger ones are less numerous, 

 and the larger the less numerous they are. If a bushel or any 

 quantity of ears of Corn are separated into piles according to 

 length, there will be one length which will include the greatest 

 number of ears and above and below this length the piles will 

 decrease in size accordingly as the length is greater or less than 

 the length of the type. This is well illustrated in Figure 467 in 



FIG. 467. Ears of popcorn, the harvest of a row across a garden, arranged 

 in columns according to length. The columns differ \ inch in length of ears 

 contained. The length of ears in longest column is between 3| and 4 inches. 

 The shortest ear is between 1 and \\ inches and the longest between 6 and 6| 

 inches in length. 



which are shown arranged according to length the ears from a row 

 of popcorn. The same fact is illustrated in Figure 468 in which 

 case beans are assorted according to size. If a string were 

 stretched over the piles of corn so as to touch the top of each pile 

 or over the columns of beans so as to touch the top of each 

 column, the string would form a curve. Such a curve is known 

 as the frequency curve and commonly variability is represented 

 by using curves, the nature of the variability being shown by 

 the relative height, breadth, and evenness of the curve. In 

 Figure 469 the variability in the weight of Irish potatoes is shown 

 by a curve. All kinds of fluctuating variations, such as number 



