12 STATISTICS OF SEX 



In the case of ilic Census families, there are fewer pairs of children 

 of the same than of opposite sexes, which result is the opposite of that of 

 a unisexual tendency. In the case of the genealogical families, the excess 

 is in the unisexual direction, but is in part due to an excess of male 

 offspring recorded in the genealogies. 



FAMILIES OF 3 CHILDREN. 



In a chance distribution the unisexual families should be one-fourth 

 the entire number. The actual number is slightly below this, so that no 

 unisexual tendency is shown. 



FAMILIES OF -i CHILDREN. 



In a chance distribution the numbers of the three classes should be 

 in the proportion 1 : -i : 3. The actual number of unisexual families in 

 the entire list is 19 in excess of the probable number. This excess is, 

 however, no greater than might well be the result of chance. The num- 

 ber of families having 3 out of 4 children of the same sex shows the 

 opposite of a unisexual tendency. 



FAMILIES OF 5 CHILDREN. 



Here again there is an excess of 8 unisexual families over the normal 

 number of 52. The effect of a unisexual tendency would be to produce a 

 number smaller than the probable one of families consisting of 3 children 

 of one sex and 2 of another, but there is an excess in the case of these 

 families. We can, therefore, only attribute the deviation to chance. 



