Dec. 6, 1915 
Inheritance of Length of Pod in Certain Crosses 
407 
The most probable single ratios have been calculated on the hypothesis 
that there are three chances for the long pod to one chance for the short 
pod. However, by the theory of probability, a deviation from the 
whole numbers nearest to these calculated ratios is far more likely to 
occur than not. The most probable deviation has been calculated by 
the conventional formula, 1 and is given in the last column of Table II. 
Since the actual are not greater than the calculated deviations, it is 
probable that there is no interference with the random segregation of 
the long and the short pod, with three chances for the long to one chance 
for the short pod. 
The third-generation families of the Florida velvet bean X Lyon bean 
were grown in an elimination field among crowding sorghum, where there 
was some selective elimination of short-podded plants (3). Hence the 
ratios are useless here. Two long-podded parents, however, of those 
whose families were grown on poles gave a total of 49 long-podded to 13 
short-podded (calculated, 46.5 + 2.3:15.5 + 2.3). In the third genera¬ 
tion of the Lyon bean X Florida velvet bean, 17 families of more than 8 
members each.from long-podded parents were grown on poles. The 
totals of the 11 segregating families among these amounted to 231 long- 
podded and 76 short-podded plants, the calculated nearest whole num¬ 
bers* being 230 and 77. The long-podded homozygotes could not be 
distinguished by inspection from the heterozygotes. These results are 
given in Table III. The abbreviations used in this and the subsequent 
tables in this paper are “V” for Florida velvet bean and “L” for the 
Lyon bean. 
Table III .—Length of pods in third-generation bean crosses from long-podded parents 
Parentage. 
Progeny ratio. 
Calculated ratio. 
Deviation. 
Probable de¬ 
viation. 
Long . 
Short. 
Long. Short. 
LV-92 . 
27 
0 
LV-548 . 
O 
3 ° 
O 
LV-569 . 
38 
O 
LV-558. 
20 
O 
LV -27 . 
28 
O 
LV-3II . 
9 
0 
LV-80. 
2 5 
12 
27. 75 : 9.25 
-2. 75 
- 4 - 1 . 8 
LV-II3 . 
22 
6 
21 : 7 
+ 1.0 
±1. 5 
IyV-279. 
24 
6 
22.5 : 7. s 
.+!■ 5 
rfci. 6 
LV-486 . 
3 i 
7 
28.5 : 9- 5 
+ 2. 5 
±1.8 
LV-91. ... 
21 
4 
18. 75 : 6. 25 
+2. 25 
±i -5 
LV-II4 . 
13 
4 
12. 75 : 4. 25 
+P. 25 
±1. 2 
LV-3IO . 
26 
8 
2 5 - 5 : 8.5 
+0. 5 
±1. 7 
LV-468 . 
15 
10 
18.75 : 6.25 
“ 3 - 75 
±i -5 
bV-527 . 
*5 
8 
17-25 : 5-75 
—2. 25 
±1.4 
LV-461 . 
28 
8 
27 : 9 
+1.0 
±1.8 
LV -392 . 
11 
3 
IO - 5 : 3 * S 
+0. 5 
±1. 1 
Total. 
231 : 
76 
230.25 : 76.7s 
+°- 75 
± 5 - 1 
1 1 have used the ordinary formula for probable deviation, which, however, does not seem to be appropri¬ 
ate (except with large numbers) to any but aitoi segregation. East and Hayes's practical test of this 
formula with large numbers (7) shows that it will in that case fit a 3 to 1 segregation with sufficient accuracy. 
Hence, the calculated probable deviations in Table III, where the numbers are small, are not reliable. 
