E. R Saunders 



61 



It also seems clear that in such mixed families the singles pre- 

 ponderate. This was the case in 33 out of 38 families, and although 

 in the remaining five the doubles were equal in number to the singles 

 or slightly in excess, it is very improbable that the deficiency of 

 singles in these cases is real. In families 9, 10, 31, and 33 the numbers 

 recorded are too small to be conclusive, and in family 35 the result 

 (9 single, 11 double) is within the range of deviation which might 

 be expected to occur, if, as appears to be the case in several families, 

 the true ratio represents but a slight excess the other way. At present 

 the data available are hardly suflScient to determine with certainty the 

 real proportion of singles and doubles occurring in these families. Until 

 the general occurrence of doubles in unions of this kind had been 

 established the number rather than the size of the families was of first 

 considei-ation. If for the moment, however, we consider only those 

 families with more than 10 members we find that they fall naturally 

 into two principal groups, in one of which the numbers suggest the 

 possible ratio 3 s. : 1 d., while in the other they approximate closely 

 to the ratio 9 s. : 7 d. Grouping these families in this way we get the 

 result shown below : — 



give 



125 



42 



give 



3% 



308 



