158 GENETICS IN RELATION TO AGRICULTURE 
with the factor for yellow body color and they give identical linkage 
values with the other factors in this group. Since the factors occupy 
identical loci in the homologus chromosomes not more than two can 
occur in the same individual at the same time. This fact was demon- 
strated in the breeding tests applied above. 
Other cases of multiple allelomorphism are known to occur in a large 
variety of species. In the silkworm there is apparently a series of 
Expectation 3 6 3 
Actual Numbers 5 4 3 21 
e r e e F, 
B BC Cc Cc 
Expectation 28.25 56.5 28.25 | 
8 29 53 3 1 
Actual Numbers é ry - . ‘ F; 
i} B BC Cc Cc 
Expectation | 7.5 15 15 | 
Actual Numbers 3 He 10 if 3 wily 2 
e e e e e e e e e | 6F, 
A AB B B BC Cc ¢C AC A 
T 
Expectation 231.25 462.5 281.35 
Actual Numbers 107 977 251 452 222 454 29 
| —“ 
e ) e e e e ° e e F,; 
A AB B B BC ¢ ¢ AC A 
Expectation 20 60 65 130 65 111.75 37.25 
Actual Numbers 21 59 66 136 58 117 82 
—1— | —— . 
® @ e @ @ @ e e @ F, 
A AB B B BC Cc Cc AC A 
L J J (Bt } 
[ J J 
1 i f 
5 6 6 12 3 
e e C) e e Fy 
AB BC AC A AD 
L _I 
t) x e Parents 
AB AC 
1 fb from 298 from 
the field the field not 
virgin 
A= texanus C= leucothorax 
B= leuconotus D= punctofemorata 
Fic. 74.—Chart showing results of a continued series of pedigree experiments with 
Paratettix involving types A, B, and C. (After Nabours.) 
multiple allelomorphs concerned in the production of larval patterns. 
As Tanaka has shown there are four larval patterns, moricaud, striped, 
normal, and plain. Each of these colors is allelomorphic to the other 
three and moreover they all apparently display the same linkage values 
with the pair of factors for yellow and white cocoon color. Like the 
multiple systems in Drosophila they give no new types by recombination 
when crossed. 
Multiple Allelomorphs in the Grouse Locust.—A very striking series of 
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