Breeding experiments which show that hybridisation and mutation etc. 235 



Table II. 



Cross. 



Number 

 of families 



Number 

 of plants 



grandißora X rubricalyx, F2 



rubricalyx x grandiflora, Fj 



(gratidiflota X rubricalyx) X grandiflora 



(rubricalyx X grandiflora) X grandiflora 



(rubricalyx X grandiflora) X rubricalyx 



(rubricalyx x grandiflora) X (grandiflora X rubricalyx) 

 (grandiflora X rubricalyx) x (rubricalyx x grandiflora) 



5 

 12 



3 

 4 

 I 

 I 

 3 



504 



1039 



373 



579 



44 



62 



193 



29 



2794 



Table III. 

 Showing distribution of the dominant character, R, in F2. 



(') Calculation of the data in table III on the basis of the mathematical theory 

 of probability shows the following results: 



Table Ilia. 



Ratios 



Frequency with which these ratios would be expected in a 

 3:1 (or 1:1) population 



343 : 35 

 518:115 

 150:99 

 171 : 129 

 217 : 156 

 133:41 



13 times in a billion trials 

 I „ „ 25000 

 7 „ „ 100 000 „ 



^ n n ^25 }, 



In« 1250 „ 



in accord with a 3 : i ratio. 



Similarly (a), (b), and (c) in section I of table III are all significantly different from 

 each other. In section IIA, the ratios marked (a) and (c) are significantly unUke. 

 Also in section II D, (a) and (c) (78 : 37 and 57 : 60) are unlike. In sections III and 

 VI the three ratios are not significantly different from each other, and in section VII 

 the deviation between (a) and (b) might occur once in 12 trials. 



