298 A. FRANKLIN SHULL 
Experiment 3. A fertilized egg which hatched in not less than 
7 nor more than 14 days became the parent of the line in the first 
column of table 5, while the second column represents the line 
obtained from an egg that hatched in about four weeks. 
The individual from the early-hatched egg yielded a line with 
22.3 per cent of male-producers, the late-hatched only 15.4 per 
cent, notwithstanding that the ‘early-hatched’ line is the older 
line by two or three weeks and might therefore be expected to 
have decreased somewhat in the proportion of male-producers. 
TABLE 5 
Showing number of male- and female-producers in two lines of Hydatina senta, one 
derived from a fertilized egg that hatched in two weeks or less after laying, the other 
from an egg that hatched in four weeks 
EARLY HATCH LATE HATCH 
Date of first | Number of o& 2’ Number of 2 9 SE OOREE | Number of o'@)| Number of 2 9 
young young | 
November | November 
22 1 11 22 2 11 
24 4 10 | 24 a | 17 
26 1 | 26 ae: 28 
28 9 25 | 28 6 37 
30 0 4] | 30 1 24 
December | | | December 
2 | 2 33 | 2 1 18 
4 1 43 4 1 22 
6 20 20 5 7 27 
9 11 10 | 8 1 40 
17 2 10 11 0 
11 2 13 8 25 
13 0 17, al 15 1 Se 
15 | 3 14* 
aL@ Galler 71 246 47 257 
Per cent of 
Gio nee ae | 29 3 15.4 
* Remainder of family not recorded. 
