552 E. G. Anderson 
TABLE 6. Summary of Linkage Data 
Pedigree no. 
Total 
number 
of 
plants 
Percentage of crossing-over 
Y-Jrl 
Pl-Sm 
Y-Sm 
111-2 
136 
213 
134 
17.5 
20.7 
6.0 
238-9 
241 
Totals 
483 
15.73 
772-3 
219 
273 
177 
158 
103 
36.1 
34.8 
28.2 
27.2 
34.0 
10.5 
9.5 
10.2 
8.9 
12.6 
40.2 
40.7 
31.6 
34.8 
36.9 
774-6 
781-2 
777-8 
779-80 
Totals 1918 
930 
32.47 
10.11 
37.42 
1 a r 1 o 
287 
98 
496 
413 
376 
187 
318 
ooo 
143 
236 
184 
37.7 
37.8 
31.0 
30.0 
26.3 
19.3 
23.6 
34.1 
25.9 
22.0 
27.2 
10.1 
6.1 
7.5 
8.7 
7.4 
6.4 
6.3 
7.6 
13.3 
14.0 
18.5 
45.6 
41.8 
38.5 
36.8 
32.7 
25.7 
29.9 
41.1 
37.8 
35.2 
37.0 
1454-6 
1457-9 
1460-2 
1463-6 
1467-8 
1469-70 
1471-3 
1476-7 
1478-80 
1481-2 
Totals 1919 
Totals 1918-1919 
3,093 
28.87 
9.09 
36.60 
4,023 
4,506 
29.70 
9.32 
10.01 
36.79 
Totals of all data 
T 
or approximately 30 units. Since in such long distances double crossing- 
over may be expected, a corrected map distance should be 30 plus twice 
the per cent of unobserved double crossovers between the two points. 
But with the high amount of interference indicated by the small number 
of observed coincident crossovers in the two regions Y-Pl and Pl-Sm, the 
corrected value for these data is probably not much above 30 or 35. The 
value 10 for the map distance between PI and Sm is probably correct 
for these data. 
