Production of Double Flowers 513 



This is proven in the simplest way by the re- 

 sult of our own experiment. 



In the double field-marigold we have the very 

 first generation of a variety of pure and not 

 hybrid origin. It shows the new attribute in 

 its full development. It has flower-heads near- 

 ly as completely filled as the best double varie- 

 ties of allied cultivated composites. In the sec- 

 ond generation it reached heads with 200 rays 

 each, and much larger numbers will seldom be 

 seen in older species on heads of equal size. I 

 have compared my novelty with the choicest 

 double camomiles and others, but failed to dis- 

 cover any real difference. Improvement of the 

 variety developed in the experiments carried on 

 by myself seems to be excluded by the fact 

 that it comes into conflict with the same difficul- 

 ty that confronts the older cultivated species, 

 viz. : the increasing sterility of the race. 



It is perfectly evident that this double mari- 

 gold is now quite constant. -Continuously va- 

 rying about a fixed average it may live through 

 centuries, but the mean and the limits will al- 

 ways remain the same, as in the case of the 

 ever-sporting varieties. 



Throughout this lecture I have spoken of 

 double flowers and double flower-heads of com- 

 posites as of one single group. They are as 

 nearly related from the hereditary point of 



