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DAVID DAY WHITNEY 



TABLE 16 

 (From Shull and Ladoff) 

 Showing number o] male-producers (cf 9) and female producers (9 9 ) in two 

 lines of Hydatina, one reared in water in ordinary air, the other in water satu- 

 rated with an atmosphere of which 60 per cent was oxygen 



table 19 had been more extended that they would have had a 

 total summary similar to those in table 16 or vice versa. 



The real point of importance not only in these experiments of 

 Shull and Ladoff but also in the present ones with air and oxygen 

 is to determine what influence caused these few mothers in both 

 the air and the oxygen experiments to produce a high per- 

 centage of male-producing daughters while the other mothers 



