506 Mutations 



tice. In the greater number of cases recorded 

 it remains doubtful whether the work said to be 

 done to obtain a new double variety was done 

 before the appearance of the preliminary indi- 

 cations or afterward. 



In the first case, it would correspond with 

 our selection of large numbers of florets in the 

 outer rays, in the second however, with the or- 

 dinary purification of new races from hybrid 

 mixtures. 



In scientific selection-experiments such cross- 

 es are of course avoided, and the process of 

 purification is unnecessary, even as in the 

 Chrysanthemum culture. The first generation 

 succeeding the original plant with disk-rays was 

 in this respect wholly uniform and true to the 

 new type. 



In practice the work does not start from such 

 slight indications, but is done with no other 

 purpose in view than to produce double flowers 

 in species in which they did not already exist. 

 Therefore it is of the highest importance to 

 know the methods used and the chances of suc- 

 cess. Unfortunately the evidence is very scanty 

 on both points. 



Lindley and other writers on horticultural 

 theory and practice assert that a large amount 

 of nourishment tends to produce double flow- 

 ers, while a culture under normal conditions, 



