LIFE-HISTORY OF ROTIFER 



243 



about any clear increase either in the maximum number of eggs 

 produced, the individual range of life, or the average length of 

 life. In four generations the average length of life in the selected 

 line is greater than the length of life in a line of individuals chosen 

 at random. In three generations the average number of eggs 

 produced by the selected line is greater than the number pro- 

 duced by an individual in a non-selected line. In all other cases 



TABLE 3 



A comparative table of the selected and non-selected lines of Proales, showing the 

 numbers of eggs produced and the length of life 



the selected line shows an average either equal to or below the 

 numbers produced in a non-selected line. These results indicate 

 that at this time selection for a greater number of eggs and a 

 longer average life-cycle in Proales is ineffective. The results 

 obtained from this selection work do not offer any explanation for 

 the great variation in maximum and average length of life, in 

 range of individual life-cycle, and in maximum and average 

 egg production mentioned earlier as occurring between the 



