98 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



out of filaments ; but a "petaloid " condition often first shows itself in the 

 anthers. In some forms it remains with them as explained in the 

 Buttercup. In the double Larkspur the concentric circles of spurred petals 

 are the result of several series of stamens having their anthers converted 

 into spur-like nectaries, the spurs fitting one into another in radial series. 



Double Flowers. 



The word ''doubling" may be applied to any organ which is multi- 

 plied ; so that, for convenience, various kinds of metamorphosis, &c, may 

 be gathered together under this head as follows. 



Beginning with bracts, it sometimes happens that the flower is totally 

 arrested. The diverted energy is now directed into bracts, which are thus 

 abnormally multiplied to a great extent. Thus arises the " wheat- 

 eared " Carnation, in which the two pairs of opposite bracts of a normal 

 flower are multiplied so as to form a long series, roughly resembling an 

 ear of wheat. 



In the ' Green Dahlia ' the florets of the heads are suppressed, so that 

 the usual small chaff-like scales become enlarged into a mass of green 

 bracts. 



The multiplication of the sepals, with or without any other perceptible 

 change, is not particularly common. An increase has been observed in 

 the Plum, Elder, Fuchsia, and Water Drop wort. It is not uncommon in 

 Tulips, Iris, Narcissus, &c. 



The corolla may have its petals multiplied irrespectively of any con- 

 version of stamens into petals. There may be two or three corollas, one 

 within another, as sometimes occurs in Campanulas. Double Stocks will 

 occasionally have many series of petals and yet retain the six stamens and 

 pistil in the centre unchanged and effective for setting seed. 



In some flowers both calyx and corolla are repeated together over and 

 -over again, being slightly separated by short internodes on the axis which 

 has elongated through the flower. This is the case with the flowers of a 

 cultivated form of Arabis albida. It has occurred in Helianthcmum 

 vulgare and in a remarkable Mignonette issued by Mr. Balchin, called 

 Reseda odorata prolifera alba.* 



Many Composites are said to be " double," but it is really a false name. 

 Thus when the "single" Dahlia was first cultivated it was described as 

 having only five petals, but is said to have soon shown eight ; probably 

 thirteen t and twenty-one followed suit until the whole head was a mass of 

 "petals." The interpretation of this is that the "head" consists not of 

 petals but of florets ; those of the " ray," on the circumference, having 

 broad-limbed corollas, and those on the " disk " having minute five-toothed 

 corollas. The number of ray-florets became increased by the conversion 

 of tubular disk-florets into broad-petalled ray-florets. 



When the tubular corolla with five petals changes to a large ray- 

 floret, two of the petals are suppressed, while the remaining three 

 become greatly enlarged. Simultaneously, the five stamens are arrested, 



* I have described and figured this in the Journal of the Linnean Society, vol. xix. 

 p. 214, pi. 32. 



t These numbers are accounted for by the law of phyllotaxis, which need not be 

 here discussed. 



