Lije Cycle of Hydatiua Senta 



ZZl 



TABLE XI— continued 



Showing the number of male- and female-producers in the progeny of sister individuals of Hydatinasenta, 

 one line being bred in spring water, the other in undiluted filtrate of old food cultures. 



♦ Remainder of family not recorded. 



Influence of Breeding From Different Parts of the Family on the 

 Percentage of Male-producers 



Experiment XL Starting June 27 with the individual which 

 became the parent of the series of generations in Experiment I 

 a series of famihes was bred from the first-born (whenever possi- 

 ble) of each successive generation, and another series from the 

 last-born of each generation. The results are given in Table XII, 



A very much greater proportion of male-producers appears 

 among the first-born. To determine whether rearing from the 

 last-born for four generations has any permanent effect in 

 reducing the percentage of male-producers, the offspring of the first 

 member of the last family of last-borns were isolated. Of the 

 family of 48, there were 37 male-producers, or over 77 per cent. 



