CHAPTER XI 



DOUBLE FLOWERS. 



Miscellaneous Cases. Recessive and Dominant Dotihling — 

 ^' Hose-in-Hose'' Flowers — The Special Case of Double 

 Stocks. 



The inheritance of doubling in flowers has been only 

 studied with success in a few instances. In one of these, 

 however, that of Stocks [Matthiola), a feature of such great 

 physiological significance has been discovered that we may 

 be sure the subject will before long assume considerable 

 importance. A special chapter, though a brief one, must 

 be devoted to it. 



Doubling, the multiplication, that is to say, of the 

 conspicuous parts of flowers, especially the petals, may 

 occur as the result of a number of various and apparently 

 quite distinct physiological processes. The different sorts 

 of doubling have been often described in the treatises on 

 plant teratology^. In the commonest kind the stamens 

 are bodily transformed into petals, as a manifestation of 

 that phenomenon which I have called Homoeoticf variation, 

 viz. the transformation of a part into the likeness of 

 another with which it stands in a series. This is the kind 

 of doubling which occurs so conspicuously in the Rose, 

 Ranunculus y Godetia, &c. In other cases doubleness is 



* A good general account of the phenomena will be found in Masters' 

 Teratology, 1869. For a more minute description see K. Goebel, 

 " Beitrage zur Kenntniss gefiillter Bliithen," Fri?igsheim's yahrbiicher^ xvii. 

 1886. 



t Materials for the Study of Variation, 1894, p. 85. 



