LIFE-HISTORY OF EOTIFER 251 



average of 4.55, and a range of length of life of 2 to 7 days, with 

 an average of 6.52 days. The line previously reared in | per 

 cent alcohol and transferred to 1 per cent only two weeks previous 

 to this isolation showed a range in egg production from 1 to 7, 

 with an average of 2.98, a range in length of life from 3 to 7 days, 

 with an average of 5.22 days. The line recently transferred 

 to 1| per cent alcohol showed a range in egg production of 1 to 6, 

 with an average of 2, and a range in length of life of 2 to 7 days, 

 with an average of 4.91 days. The line reared continuously in 

 malted milk under normal culture conditions showed a range for 

 egg production of 1 to 28, with an average of 19.26, and a range 

 in the length of life of 3 to 7 days, with an average of 5.81 days. 



In general during the twenty-one weeks in which individuals 

 of a line of Proales were subjected continuously to the fumes of 

 J and ^ per cent ethyl alcohol the maximum and average number 

 of eggs produced was reduced in proportion to the percentage of 

 alcohol used, but the average length of life was very Uttle in- 

 fluenced. Table 5 gives a summary of the range and average 

 egg production and the range and average length of life of all 

 the individuals studied throughout the experiment. In neither 

 of the lines subjected to I and ^ per cent alcohol is there a con- 

 tinual decrease in the average of either character studied through- 

 out the successive generation. 



Tests for inheritance of the effect of alcohol. At the beginning 

 of the twenty-fourth week both alcohol lines were discontinued 

 and their progeny returned to malted milk only. At the end of 

 the first week in normal conditions (twenty-fifth week of the 

 experiment) isolations of the second generation individuals were 

 made for determining the egg production and average length of 

 life. In the line descended from the progeny of the i per cent 

 alcohol group the range of egg production was from 9 to 27, with 

 an average of 17.77, as compared with a range of 3 to 23, with an 

 average of 12.33 eggs in the last generation in j per cent alcohol. 

 The range of life at this time was 3 to 7 days, with an average of 

 5.58 days, differing little from the range and average in the last 

 isolation in j per cent alcohol. In the line descended from 

 individuals reared in ^ per cent alcohol the range in egg produc- 



