254 



P. W. WHITING. 



The first female (9 No. i), produced forty-nine males and 

 forty-seven females. As later results show she had in all proba- 

 bility mated. Table I. shows the progeny of mated females 

 descended from 9 No. I. No variation of sex-ratio correlated 

 with age of the mother or lapse of time since mating could be 

 detected. 



The first column of Table I. gives the designation of the parents. 

 The various matings of a given generation are designated by the 

 letters of the alphabet, as F 3 a, F 3 b, etc. In case there are more 

 than twenty-six matings in any generation, the succeeding 

 matings are numbered, as F 3 i, F 3 2, etc. 



Omission of letters or numbers denotes that the parents in 

 question are elsewhere summarized or else produced no offspring. 



The second column denotes the generation of the offspring 

 and the third and fourth columns denote the males and females 

 respectively. 



The points of interest to be noted in Table I. are as follows: 



Each of the fifty-one females produced females, and all but 

 F 7 e, which produced a single female only, produced males. 



Considerable variation in sex ratio obtains in different frater- 

 nities, usually with excess or equality of females. 



An attempt to correlate sex ratio in the maternal fraternities 

 with that of the progeny resulted as follows : 



Fraternities with excess females (131 cf cf : 237 9 9 ) gave 236 cf cf : 374 9 9 

 = i : 1.6. 



Matings of progeny of 9 no. i (49 cf c* : 47 99) gave 122 cfcf : 180 9 9 



Fib (26 cf cf : 29 9 9) " 64 cf cf : 69 9 9 



Fraternities with equality of sexes (75 cf cf : 76 99) gave 186 cf cf : 249 9 9 

 = i : 1.3- 



It is seen that a higher female ratio is obtained in the progeny 

 of those fraternities in which the females were in excess of the 



