Breeding experiments which show that hybridisation and mutation etc. 25Q 



finally came into bloom. Treated as a population, it is clear that 

 in the last three families the time of blooming was intermediate 

 between that of grandiflora a rubricalyx and pure grandiflora. The 

 earhest plants to bloom in these three families were much later 

 than any plants in the Fg cultures. There is therefore obviously no 

 "segregation" here. The meaning of the early blooming of famiUes. 



Fig. 22. (Rubricalyx :< grandiflora) X grandiflora. Foliage p. s. 



68 and 69 is unknown. In the complex physiology of flower- production 

 many conflicting environmental influences must be at work. Wlren 

 rubricalyx x grandiflora is crossed back with rubricalyx (Cult. 70), the 

 offspring bloom rather earlier than the F2 families, again showing 

 intermediacy of behaviour. 



The double-reciprocal crosses are also of interest as regards time of 

 blooming. Thus (rubricalyx x grandiflora ) x (grandiflora x rubricalyx) 



17* 



