Production of Double Flowers 503 



brightest heads of the most beautiful double 

 commercial varieties of composites. Even the 

 best white camomiles (Chrysanthemum ino- 

 dorum) and the gold-flowers ,or garden-mari- 

 golds (Calendula officinalis) do not come nearer 

 to purity since they always have scores of little 

 tubular florets between the rays on their disks. 



Real atavists or real reversionists were seen 

 no more after the first purification of the race. 

 I have continued my culture and secured last 

 summer (1903) as many and as completely 

 doubled heads as previously. The race has at 

 once become permanent and constant. It has of 

 course a wide range of fluctuating variability, 

 but the lower limit has been worked up to about 

 34 rays, a figure never reached by the grandi- 

 florum parent, from which my new variety is 

 thus sharply separated. 



Unfortunately the best flowers and even the 

 best individuals of my race are wholly barren. 

 Selection has reached its practical limit. Seeds 

 must be saved from less dense heads, and no 

 way has been found of avoiding it. The ray- 

 florets are sterile, even in the wild species, and 

 when growing in somewhat large numbers on 

 the disk, they conceal the fertile flowers from 

 the visiting insects, and cause them also to be 

 sterile. The same is the case with the best cul- 

 tivated forms. Their showiest individuals are 



