The Inheritance of Quantitative Characters in Maize 33 
of the progeny of the four ears from it that were followed into 
the F 3 generation. The progeny of ear (60-3x54) 1-1EO, a 16- 
rowed ear, showed a modal condition of 16 rows, with ears 
having both 18 and 20 rows. None had less than 12 rows, but 
this undoubtedly was an accidental circumstance because the 
12-rowed class occurred 15 times. In a perfect sample of the 
population, therefore, one would expect to find individuals with 
both 10 and 8 rows. At the same time the modal condition of 
this family was unquestionably sixteen rows, while that of the 
other three families was twelve, fourteen, and twelve. This 
result is very striking when compared with the F 3 families 
( 60-3x54) -5-3 and (60-3x54)6-5, where the modal conditions are 
10 and 8, respectively. 
Five F 2 families of the cross 60-5x54 (Table 10) were grown. 
These were again different in character. Family (60-5x54) -6 
was characteristically twelve rowed, while family (60-5x54) -11 
was characteristically 8 and 10 rowed. Unfortunately only a 
single 8-rowed ear from family (60-5x54)2 was carried to the 
F 3 generation and its progeny tended to form an 8-rowed type. 
Most remarkable for its tendency to form a non-variable family, 
however, was family (60-5x54) -11. Five ears were grown and 
in each there was a notable tendency toward an 8-rowed strain. 
It may be doubted very seriously whether selection toward a 
16-rowed type in all of these families would be successful. Suc- 
cess might come in one or two instances, — for gametic possibili 
ties of a 16-rowed race may still exist in some of the families. — 
but it would not be likely in every family. On the other hand, 
the two fraternities raised from ears (60-5x54) 12-1ES and 
( 60-5x54) -12-2ES are very high in variability and show that they 
contain potentialities of yielding races averaging from 16 to 20 
rows. 
In cross 60-8x54, Table 11, a race characteristically 8 rowed 
and a race characteristically 12 rowed were obtained in the F^ 
generation. ^ 
In Table 12 are presented data derived from a cross of Tom 
Thumb pop and Missouri dent. Few records are available ex 
cept those of F 2 and F 3 families grown in 1911. No genera- 
tion was grown in 1911 and the records of F x ears produced in 
1910 were accidently destroyed. There are entered in the table, 
however, under the designation of F x generation, such records 
as were obtainable from the ears kept as samples. Tho both 
parent varieties were grown in 1911, no record was obtained of 
the ears of Missouri dent since this variety failed to mature in 
Massachusetts. Owing to poor germination only a few plants 
of Tom Thumb pop were grown in 1911 and these, because of the 
unfavorable weather in early summer, while they were develop- 
2 
