510 Mutations 



This conception of the inner nature of double 

 flowers explains the fact that the varietal mark 

 is seldom seen to be complete throughout larger 

 groups of individuals, providing these have not 

 been already selected by this character. 

 Tagetes africana is liable to produce some 

 poorly filled specimens, and some double va- 

 rieties of carnations are offered for sale with the 

 note that the seed yields only 80% of doubles. 

 With Chrysanthenmm coronarmm and blue-bot- 

 tles this figure is often announced to be only 

 about 50^. No doubt it is partly due to im- 

 purities, caused by vicinism, but it is obviously 

 improbable that the effect of these impurities 

 should be so large. 



Some cases of partial reversion may be inter- 

 preted in the same way. Among the garden 

 anemones, Anemone coronaria, there is a va- 

 riety called the '^ Bride," on account of its pure 

 white flowers. It is for sale with single and 

 with double flowers, and these two forms are 

 known to sport into one another, although they 

 are multiplied in the vegetative way. Such cases 

 are known to be of quite ordinary occurrence. 

 Of course such sports must be considered as 

 partial, and the same stem may bear both types 

 of flowers. It even happens that some partic- 

 ular flower is partly double and partly single. 

 Mr. Krelage, of Haarlem, had the kindness to 



