SHULL: DUPLICATION OF A LEAF-LOBE FACTOR 
TABLE 5 
437 
Composition of F; Families from Fz, Parents Having B Lobes in Crosses between B. 
Heegeri simpiex and a Biotype of B. bursa-pastoris heteris from Tucson, Arizona 
Pedigree Numbers 
heteris rhomboidea tenuts stmplex | Ratio 
F F AB aB Ab | ab B:b 
2 3 
14476 ee ae me -- Lo 
14477 49 155 maa ris 1:0 
13202 14479 I4 9 mae = 1:0 
14482 22 155 = = I-20 
14483 30 98 — == r0) 
14487 30 3 = Fi 1:0 
14488 zante | 68 = = 1:0 
14489 6 21 — = LC. 
13203 14490 — 80 — a 50/51 
14495 a | 30 = = 1:0 
14496 = 245 — — E20 
14499 2 G/ — — 120 
| 14503 2 74 = ae 1:0 
14506 = 115 — — iste, 
poo | 14508 = 60 = = jee, 
| 14509 28 57 = — 3410) 
| 14511 2 44 = = LO 
eae | "14513 56 18 — == 1:0 
14514 = 13 — —_ 1-20 
13202 | 14480 ; 93 216 16 i 3 x 16.225505 
13203 14492 II 12 I — 23-00) -85 
13204 AG 5 76 42 5 a 4-752 
14478 58 9 19 3 3:05 00 
13202 14484 = 125 = 82 1.52701 
14485 36 I 18 = ZOO 
14500 59 104 12 27 AslOrsck 
7 |\eskaso4 — 66 = Ag 2.44:1 
a 14505 3 60 = | 24 2362231 
14510 gI 61 36 | — AOE 
zygous state, 7. e., BbB’b’; while 7 families gave ratios which may be 
appropriately referred to the 3 : I group, indicating that the parents 
of these had but one of the B factors and this one heterozygous, e. g., 
Bbb'b’ or bbB’b’. According to theoretical expectation for the number 
of families given in Table 5 these three groups should occur in the ratio 
4 The occurrence ot one simplex in this family is of unknown significance. It 
may represent an unusually defective 15:1 ratio, but the deviation is so much 
greater than in any other family that other possibilities seem more likely to be true. 
From all my experience with these pedigrees, it seems probable that this “simplex” 
individual is merely a rhomboidea modified by the suppression of the B lobing. There 
remain also the possibility of ‘“‘loss mutation”’ and of a technical error. 
