Double Flowers and Flozverheads. 197 



the Hgulate florets are female, and inasmuch as very 

 often all the flowerheads on a single plant attain to this 

 degree of doubling" the best variants cannot serve as 

 seed-parents. But two further types are always found 

 with yellow discs which are either unifcjrm (Fig. 34A) 

 or contain scattered ligulate florets amongst the tubular 

 ones, as is so often seen in Chrysantheniwn uidicuni and 

 Zinnia elegans. The double Bellis perennis also, if grown 

 from seeds, is highly variable in this respect. These 

 two types are fertile and therefore constitute the seed- 

 parents of the variet}^; if the plants with central ligulate 

 florets (see p. 185) furnish sufficient seed the harvest 

 is saved exclusively from them ; but they often set little 

 or hardly any seed. 



This unavoidable restriction in the choice of the seed- 

 parents and the frequent difficulties of selection depen- 

 dent on it account for the fact that bought samples of 

 the seed of double composites often give rise to only 

 a relatively small proportion of the desired type, as has 

 long been known^ to be, and still is, the case {Chrysan- 

 thennnn coronariuni sometimes only 50%, Centaurea 

 Cyanus 40-50%, Tagctes ofricana with rare exceptions 

 double etc.).^ 



Many double varieties of composites seem to be al- 

 most as old as horticulture itself (See Vol. I, p. 183). 

 According to the oldest accounts the degree of doubling 

 and the range of its variation were formerly the same as 

 now. 



Finally I have to mention the fact that bud- and sec- 

 torial variations are found in tliis case as well as in others. 



^ E. g., Pyrcthrum roscum. Dahlia, Chrysanthemum indicum, ac- 

 cording to Verlot, Production ct fixation dcs varictcs, i(S65, p. 83. 



^ See the catalogues of Penary, and Haaoe & Schmidt of Er- 

 furt, Veitch & Sons of London and Sutton & Co. 



