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116 REPORT OF THE CONFERENCE ON GENETICS, 
fig. 26) In F, segregation into three red to one yellow took place (42 : 18). 
In this generation, however, there were four distinct and discontinuous 
types, two reds, and two yellows. One type of red was like the original 
‘Fireball,’ while the other was quite different, corresponding with ‘Rouge 
Caroubier’ (Carmine Red) in “ Rép. de Coul.’’ t. exiii. (tone 4) ; this shade 
is due to the red flesh showing through a white or colourless skin. 
One type of yellow was quite different from the original ‘ Golden 
Queen, corresponding with ‘Jaune Gomme Gutte’ (Gamboge Yellow) in 
“ Rép. de Coul.”’ t. xxv. (tone 4) ; this shade is due to the yellow flesh showing 
through a bright yellow skin. The other type of yellow was like the 
original ‘ Golden Queen’ corresponding with ‘Jaune Soleil’ (Sunflower 
Yellow) in “ Rép. de Coul.”’ t. xxiii. (tone 3) ; this shade is due to the yellow 
flesh showing through a white skin (see fig. 26). 
These four types occurred in F, approximately in the ratio of 
9:38:38: 1 respectively (81:11:10: 8), suggesting that the Mendelian 
characters in this case are two pairs, which are apparently (1) red and 
yellow flesh, red being dominant and yellow recessive ; (2) yellow and 
white skin, yellow being dominant and white recessive. It is probable, 
however, that the unit-characters are really simply (1) presence (R) and 
absence (r) of red in the flesh ; (2) presence (Y) and absence (y) of yellow 
in the skin; presence being dominant and absence recessive in both. 
In that case the gametic formula of ‘Fireball’ would be (R+Y), 
‘Golden Queen’ would be (r+y), the Carmine Red would be (R+y), and 
the Gamboge Yellow would be (1+ Y). 
It is evident, therefore, that the red colour of the ‘ Fireball’ tomato is 
due to at least two gametic factors. 
Broadly speaking, red and yellow tomatos may be said to behave as 
Mendelian characters, red being dominant and yellow recessive: at the 
same time Mendelian analysis shows that there are at least two types of 
red tomatos, viz. red flesh in a yellow skin and red flesh in a white skin: 
similarly there are at least two types of yellow tomatos, viz. yellow 
flesh in a yellow skin and yellow flesh in a white skin. 
The practical importance of these results to the breeder lies in the fact 
that any of these four colour types can be quickly fixed (no matter how 
they may have arisen) by anyone possessing a knowledge of the 
Mendelian principles, and their various behaviours when crossed can be 
faithfully predicted for any number of generations. 
THe Rep Cotour or ‘Crimson Kina’ ANTIRRHINUM. 
The race of dwarf Antirrhinwm majus grown in gardens as ‘Crimson 
King’ has red corolla segments corresponding with the shade ‘ Rouge 
Caroubier ’ (carmine red) of “ Rép. de Coul.’’ t. cxiii. (tone 4), 
In my experiments this form was crossed with ‘ Yellow Prince,’ 
a dwarf race with yellow segments corresponding with the shade ‘ Jaune 
Soufre’ (sulphur yellow) in “Rép. de Coul.” t. xviii. (tones 1 and 2). 
All the F, cross-breds were indistinguishable from ‘Crimson King,’ 
red colour being dominant and yellow recessive. In F, segregation took 
place, there being approximately three ‘Crimson King’ to one ‘ Yellow 
Prince’ (116 : 41), 
