SOME NEW PRINCIPLES 



235 



75 % Yellow 25 % Green 



When the two parents of a generation are alike, their 



character is only written once. The two forms crossed in each 



case are printed in itahcs. The ancestors in respect of which 



their pedigrees difier are printed in capital letters. 



The result of the type of mating at the right is 

 well known, and is written there to emphasise the 

 fact that the result of the mating to the left is not 

 known. 



Anyone unfamiliar with Mendelian phenomena, 

 and with only these two pedigrees to go upon, would 

 unhesitatingly declare that the result of the two 

 matings would not be the same. He would predict 

 with some confidence that, the result of the mating 

 to the right being what it is stated to be, the result 

 of the mating to the left will differ from it in showing 

 a much lower percentage of greens in the second 

 hybrid generation. " I cannot but believe," he 

 would argue, " that the great weight of yellow 



