342 



Aaron Franklin Shiill 



25 members, 34 lay between 26 and 35 inclusive. The position 

 of the male-producers in these is given in Table XVI. 



It is evident, I think, that there is no accumulation of male-pro- 

 ducers at either end of these families, and hence that the shorten- 

 ing of the families by starvation is not responsible for the increased 

 percentage of male-producers in partially starved families. 



TABLE XVI 



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

 from 34 partially starved families of more than average length. 



O J 



Position in Family 



NUMBER or MALE-PRODUCERS OCCUPYING EACH PLACE IN FAMILY 



j5<; 



^ ii 2345678 91011 121314151617181920212223242526272829303132333435 



31-35 13 

 26-30! 21 



2| 3 



4! 5 



9jio 

 ii'ii 



Identity of Sexual Eggs and Male Eggs 



Maupas ('90b) inferred from certain numerical relations that 

 the resting eggs of Hydatina senta are fertilized male eggs, and 

 that upon females which are destined to produce females impregna- 

 tion has no effect. Subsequent investigations have only tended 

 to make the identity of male eggs and sexual eggs more probable, 

 but direct observations to establish the point have been wanting. 



Previous workers have all found that each female laid only 

 one kind of egg; (il parthenogenetic male eggs, or (2) partheno- 

 genetic female eggs, or (3) fertilized resting eggs. If the resting 

 eggs are fertilized male eggs, it would seem possible, by limiting the 

 number of spermatozoa that enter a female during copulation, 

 to secure from her some resting eggs and some male eggs. Since 

 one female can rarely lav over 16 or 17 resting eggs, and usually 

 lays only 10 or 12, even under favorable circumstances, the num- 

 ber of spermatozoa must be less than ten to afford any consider- 

 able probability of getting both kinds of eggs from the same 

 female; or at least less than ten must be successful in entering 

 eggs. 



