512 Messrs Stratton and Compton, On Accident in Heredity, etc. 

 Rejecting the negative solution we get - = 0"22, and from (6) 



^ = 0-048. 

 r 



We may take the numbers 3 : 14 : 65 as approximately repre- 

 senting the ratios p :q :r. Then we get 



^_55 

 i^ ~ 45 ' 



a surprisingly close fit to the observed figures (p. 511). 



It is not desired to press this particular case too strongly, 

 save as affording an instance in which the admission of an 

 " accidental " factor brings an otherwise discordant inherited 

 character into harmony with known laws. 



^ ^ ^ ^ :j^ 



The above calculations can easily be adapted to suit cases in 

 which the reversal of a character only takes place in one di- 

 rection. Such a case would be that of the functional asymmetry 

 to which the terms right- and left-handedness are usually applied. 

 Here the effects of education seem to tend steadily to the con- 

 version of left-handed persons into right-handed, and probably 

 never act in the opposite direction. 



The object of this note is to show that it is possible, by the 

 exercise of assumptions which seem to be justifiable, to account 

 for certain cases to which the usual Mendelian formulae do not at 

 first seem to apply. The case we have considered specially is an 

 exceptionally favourable one from the present point of view : for 

 educational influence seems to be absent ; accidental change of 

 character seems readily to be possible, and would, so far as we 

 can see, occur with equal ease in either direction. 



