88 



INHERITANCE IN GUINEA-PIGS. 



In each array of animals of known constitution and stock the number 

 of animals involved, the mean grade of dilution, and the standard 

 deviation of the frequency polygon are given. It will be noticed that 

 the standard deviations decrease as the analysis is made closer. For 



Red Red, 



White 



FIG. 5. Variations in intensity of yellow. Formula and 

 stock printed near mode of each distribution. 



example, the standard deviation for all dilute blacks is 1.53, for dilute 

 blacks of formula CdC a is 1.13, and for those of formula CdC a and of 

 South American stock is 1.02. The corresponding numbers for dilute 

 yellows are 1.10, 0.76, and 0.59, respectively. 



