LIFE CYCLE OF HYDATINA SENTA 



119 



TABLE 17 



Showing number of male-producers and female-producers in the progeny of two sister 

 individuals of Hydatina senta, the one line being reared at a temperature of 18° 

 to 23° C, the other at 23° to 26'- C. Male-producers are designated d" 9 , female- 

 producers 9 9 . 



18° TO 23° C. 



NO. OF 

 GENERATION 



DATE OF 

 FIRST 

 YOUNG 



NO. OF 



0^9 



1 Oct. 8 



2. 



3. 



4. 



5. 



6. 



7. 



8. 



9. 

 10. 

 11. 

 12. 

 13. 

 14. 

 15. 



16. 

 17. 

 18. 

 19. 

 20. 



21. 



22. 

 23. 



10 

 12 

 14 

 15 

 17 

 18 

 20 

 21 

 23 

 25 

 27 

 28 

 30 

 31 

 Nov. 1 

 2 

 3 

 5 

 8 

 10 

 12 

 12 

 13 

 15 

 18 

 18 



Total 



Percentage of cf 9 



37 

 11 

 13 

 2 

 

 

 

 10 

 

 4 

 9 

 2 

 31 

 6 

 

 8 

 1 

 

 4 

 12 

 2 

 2 

 2 

 

 

 1 

 2 



NO. OF 



9 9 



2 

 34 

 32 

 12 

 31 

 35 

 48 



4 

 17 

 27 

 34 

 17 

 13 

 32 

 14 

 20 

 23 

 43 

 33 

 14 



5 



9 

 11 

 19 

 32 

 31 







NO. OF 

 GENERA- 

 TION 



10 



11 



12 

 13 

 14 

 15 

 16 

 17 



18 



19 

 20 

 21 

 22 

 23 

 24 

 25 

 26 



27 



28 



23° TO 26° C. 



DATE OF 



FIRST 

 YOUNG 



NO. OF 



£^9 



Oct. 7 

 9 

 10 

 11 

 12 

 14 

 15 

 17 

 18 

 20 

 20 

 21 

 22 

 24 

 26 

 27 

 30 

 31 



Nov. 2 



3 



4 



4 



5 



7 



8 



10 



11 



13 



14 



16 



16 



18 



19 







1 



3 



6 



3 



19 



1 



1 



4 



18 



2 



17 



7 



4 



7 



14 



3 



4 











2 



5 







2 







5 



4 







1 



1 



2 



1 



6 



143 

 21.3 



NO. OF 



9 9 



13 



6 



9 



20 



28 



13 



15 



6 



14 



12 



31 



11 



16 



18 



18 



10 



30 



15 



3 



12 



4 



5 



7 



24 



21 



25 



12 



17 



10 



11 



35 



29 



26 



526 



