Life Cycle of Hydatina Senta 



341 



largely male-producers, the mother would be able notwithstand- 

 ing the small quantity' of food to prolong her family to include all 

 the male-producers. But it the middle third of the family were 

 destined to be chiefly female-producers, then partial starvation 

 would prevent this middle third from being produced at all. 

 If this be the true explanation of the higher percentage of male- 

 producers in the starved families, then those families which reached 

 more than the average length should show an accumulation of 

 male-producers in their latter portions. There were 76 starved 

 families in my experiments, including 1876 members, or an average 

 of 24.6 per family. Of the 41 families that contained more than 



TABLE XV 



Showing the number of male-producers occupying the various places in their respective families, compiled 



from S49 families. 



SIZE OF FAMILY 



NO. OF 

 FAMILIES 



5'-S6 



46-50 



41-45 

 36-40 



31-35 



26-30 

 21-25 

 16-20 



II-I5 



51-56 



46-50 



41-45 

 36-40 



3'-35 

 26-30 

 21-25 

 16-20 

 11-15 



6i 



36 



35 

 46 



45 

 31 

 34 

 29 



32 

 6i 



36 



35 

 46 



45 

 31 

 34 

 29 



NUMBER OF MALE-PRODUCERS OCCUPYING EACH PLACE IN FAMILY 



I 2 3 4! 5 6 7 8 91011121314151617181920212223242512612728 



29 



30 



313 

 3028 

 I5I2 



4 



4j 6 



9 

 91 

 61 



3^ 



16 15 



25; 

 14 



34 



24 



35 



3637 



3839 



161415 

 21 23 20 

 13 10 II 



5 5 3 



40 



42 



43 



44 



14 8 



15 16 

 6 5 



45 



46 



811 

 14 II 



47 



5° 



5^ 



= 313 



^5 

 13 



I4JI3 

 7 8 



54155:56 



