754 Isabel McCracken 
Thus in the three series together there were a total of 43 bivoltin 
broods in 1907. These broods were reared in the summer of 1907. 
In the summer of 1907, five series of matings were made 
within these series and in the spring of 1908, these five series 
of broods were reared from the eggs that had lain over the winter. 
These matings were distributed as follows: 
Series H, the 1907 bivoltin material of Series E, Table III. 
Series I, the 1907 bivoltin material of Series F, Table ITI. 
Series J, the 1907 bivoltin material of Series G, Table III. 
Series K, the 1907 univoltin material of Series F', ‘Table III. 
Series L, the 1907 univoltin material of Series F, Table III. 
In the spring of 1908, when these broods had reached maturity, 
a total of 298 matings were made. 
The distribution and results of these matings 
may be tabu- 
lated thus (see also “Table of Descent’’): ‘ 
TABLE Iv# 
TOTAL RATIO OF | PERCENT- 
| BROOD CONDITION NUMBER | NUMBER | 
NUMBER BIVOLTS AGE OF 
| OF PARENTS OF OF 
OF TO ‘| UNIVOLTS 
AND LINEAGE BIVOLTS | UNIVOLTS 
BROODS UNIVOLTS | 1908 
Semespel seer: celeste ' —04—05—06+07 | 209 31 178 15 & 85+ 
Sets disooouue ooboe | —04+05—06+07 31 a9 Pes Nei 1-73 7ot+ 
SETIERE IE Aus te ce rk « —o4+05+06+07 12 eee 6 It 50+ 
Seriesmbcnanaeviie <s | —0o4—05—06—07 35 9 26 I 328 74+ 
Series) Ds are.c -tcveesise' | —o4+o5—o6—07| II g 8 2—9 21 foes 
* Note added September 2°, 1909. In 1909 Series H, through the bivoltin line produced 74 per 
cent U; Series I produced 43 per cent U; Series J produced 32 per cent U. 
Comparing Series A (Table I), Series A’ (Table II), Series E 
(Table III) and Series K (Table IV) representing continuous 
selection of hybrid uni(bi)voltin through four consecutive years 
(four generations from the hybrid parent), we find the univoltin 
continuously predominating but with gradually decreasing per- 
centage; thus, 100 per cent (1905), go per cent (1906), 88 per 
cent (1907) and 74 per cent (1908). 
Comparing Series B (Table I), Series D (Table II), Series G 
