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SCIENCE [N. 8. Vou. XXXV. No. 897 
Determiners in Germ Plasm of 
No. of Horned and Hornless Offspring 
Males Females. 
Male Female 
Horned | Hornless| Horned | Hornless 
Soma Xxhhli (hornless)...............++ XXhhII (hornless) 
GametespXehleeemee eeceseeetceecocecteseceses XAT 
chi 
Zygotes XahhIi (hornless)...............--- XXhhIT (hornless) 0 4 0 12 
Soma XahhIi (hornless)..................| X XAT (hornless, simplex) 
Gametes Xe oie ccecs- cnc cece oseeeeiecennces XHAI 
i. UR aap eae saon ke Dacceaaconenn dosen XhI 
Zygotes Xx HhIi (horned)................+ XX HhIT (hornless) (2) (2) (0) (2) 
Xahhh (hornless).........--+0.0++5 XXhhIT (hornless) 2 2 2 
Soma Xxhhh (hornless)...............0 XX HAITI (horned) 
Gametes oe BERD EGS omR HOU ROUGE EEO oMBHneoneS XAT 
Zygotes NHL (horned )...............0+. XX HhII (hornless) 15 0 0 24 
Soma XxHhii (horned, simplex) ..... XXhhII (hornless) 
Grarmeiey 2°08 0h rocoonaedsagoeocennodsaccnoeaeece XAT 
XAL 
xi 
ahi 
Zygotes XxHhIi (horned)..............06+ XX AhI (hornless) (.5) (.5) (0) (8) 
XahhTi (hornless) ......-...200+0+ XXL (hornless) 0 1 0 8 
Soma X«#HhIi (horned, simplex) ..... XX HhIT (hornless, simplex) 
(GametesPxellememecctencerceicecteseheeccser: XHI 
ROR eta eatetiodistio selndeaasesee XAT 
re 
ahi 
Zygotes Xa Hi) .....2.....-..02+¢ 0.000% XXHAHTI (horned) 
Xx Ahh } (horned!) ieee XX AIL 
EXOD RLOM yeceeeustteee ceiensercoucse xxi} (hornless ) (7.5) (2.5) (2) (6) 
XahhTi (hornless)........00s0000.+8 XXANLIL 6 4 1 7 
Soma XxHhIi (horned, simplex)..... XXHHITI (horned ) 
(Gametes) Xela eeecsestancescnccnonaicescece XHI 
XAT 
ahi 
hr 
Zygotes XxHHTi (horned)................ XXHHII (horned) (10) (0) (4) (4) 
Xa HhTi (horned)........-...00+++ XX HhII (horniess) 10 0 4 ze 
Soma va HAT (horned)...........2..0+ XXII (hornless) 
Gamietes) AGH. es as cccesee scan cedeene sates XI = 
Ahi 
Zygotes XxHhIi (horned)...........-....-. XX HhII (hornless ) 5 0 0 8 
Soma <AxvHHNi (horned)................: XX HHI (horned) 
Gametes ae Petes eek eaeace pa naste tester XHI 
xii 
Zygotes XxHHTi (horned).........+...-+++ XXHAHIT (horned) 6 0 14 0 
tor, then (designated in the table by the letter 
I, its absence by 7), will always be double in 
the female and single in the male and, in the 
gametes, will always be associated with the sex- 
chromosome, which is designated through- 
out by the symbol X; its absence by x In 
the zygote the single inhibitor is incapable of 
preventing the development of the determiner 
for the horn (H) even when the latter is only 
simplex. But the double inhibitor is capable 
of preventing the single horn (Hh) deter- 
miner, but not the double determiner (HH). 
The table gives a summary of matings 
used, their hypothetical somatic and gametic 
composition, and the proportion of each sort 
of zygote that will be formed in each sex. — 
