Production of Double Floivers 499 



But the rarity of the anomaly was exactly the 

 indication wanted, and the same deviation 

 would have had no signification whatever, had it 

 occurred in a group fluctuating symmetrically 

 around the average figure. On the other hand, 

 the observed anomaly was only an indication, 

 and no guarantee of future developments. 



Here it should be remarked that the indica- 

 tion alluded to was not the appearance of the 

 expected character of doubling in ever so slight 

 a measure. It was only a guide to be followed 

 in further work. The real character of double 

 flower-heads among composites lies in the pro- 

 duction of rays on the disk. No increase of the 

 number of the outer rays can have the same sig- 

 nificance. A hasty inspection of double flower- 

 heads may convey the idea that all rays are ar- 

 ranged around a little central cluster of disk- 

 florets, the remainder of the original disk. But 

 a closer investigation will alwavs reveal the 

 fallacv of this conclusion. Hidden between 

 the inner rays, and covered by them, lie the 

 little tubular and fertile florets everywhere 

 on the disk. They may not be easily seen, but 

 if the supernumerary rays are pulled out, the 

 disk may be seen to bear numerous small 

 florets at intervals. But these intervals 

 are not at all numerous, showing thereby that 

 onlv a relativelv small number of tubes has been 



