No. 582] SHORTER ARTICLES AND DISCUSSION 383 



that there was room, as matters stood, for 1 

 tevant published and for the work that I ( 



A METHOD OF CALCULATING THE PERCENTAGE OF 

 RECESSIVES FROM INCOMPLETE DATA 



In the very interesting article on "The Inheritance of Left- 

 handedness" by Professor Ramaley in the December number of 

 the Naturalist, a table is given on page 73i> showing the propor- 

 tion of right- and left-handed children in families where both 

 parents are presumably heterozygous for right- and left-hamh'd- 

 ness, including only families with left-handed children. In 93 

 such families there are 282 right-handed and 116 left-handed 

 children. 1 This gives 29.13 per cent, of left-handedness in these 

 families. It is clear, however, that this does not represent the 



Total Number of Children from Parents Heterozygous for Right- and 



true Mendelian proportions if right-handedness is a simple Men- 

 delian dominant over left-handedness. For instance, in families 

 where both parents are heterozygous and in which there is only 

 one offspring, the probabilities are that only one family in four 

 will show the recessive character. From the total population re- 



*Archiv. de Zool. Exp. et Gen. (4), IX; (5), VIII 



*By oversight in Professor Ramaley 's additions one column of right- 

 handed children was omitted, so that the numbers given in the table are 



