40 STATISTICAL METHODS. 



Multimodal curves differ in degree. The modes may be so 

 close that only a single mode (usually in an asymmetrical 

 curve) appears in the result; or one of the modes may appear 

 as a hump on the other; or the two modes may even be far 

 apart and separated by a deep sinus (Figs. 7 to 10). 



6.5 4.5 3.5 2.5 1.5 .5 0.5 1.5 2.5 3.5 4.5 5.5 6.5 7.5 

 FIG. 7. 



Pearson has offered a means of breaking up a compound 

 curve with apparently only one mode into two curves having 

 distinct modes; but this method is very tedious and rarely 

 applicable. 



2 

 FIG. 8. 



The index of divergence of two modes of a multi- 

 modal curve is the distance between the modes expressed in 



