44 Plant-Breeding 



TTwTnwT TXT Tie NUMBER OF INDIVID- 



UALS IN EACH CLASS (/) 



5.1- 6.5 1 



6.6- 8 4 



8.1- 9.5 6 



9.6-11 29 



11.1-12.5 30 



12.6-14 37 



14.1-15.5 39 



15.6-17 43 



17.1-18.5 34 



18.6-20 26 



20.1-21.5 18 



21.6-23 8 



23.1-24.5 5 



24.6-26 2 



26.1-27.5 2 



27.6-29 1 



29.1-30.5 _1 



286 



Here we have what is called a "frequency distribution," 

 representing the crop as it falls into the different groups. 



The curve in Fig. 8, known as the "Quetelet curve," 

 represents the results graphically. 



The frequencies, that is, the number of times each 

 measurement appears (see column / in the table), are 

 plotted on the axis of ordinates, line A-C, and the classes 

 on the axis of abscissas, line C-B. For the purpose of 

 plotting and working the data the mid-class is used, that 

 is, 5.8 inches instead of 5.1-6.6 inches, and so forth. 



Mode. We see by inspection of the foregoing data 

 that there is one group of the most common height, that is, ( 

 there are more plants having a height of 15.6 to 17 inches 

 (16.3) than any other class. 



The group containing the greatest number of plants, 



