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XXII. — On an instance of Monstrosity in a Moss. 

 By Edwin J. Quekett, Esq., F.L.S., &c. 



Read October 18, 1843. 



It is well known at the present time that the several organs that 

 constitute the flower and fruit of a plant, are but modifications of 

 leaves ; that is, that these organs are impressed, at their earliest for- 

 mation, with a different law in their development, becoming subservi- 

 ent to the functions of reproduction instead of nutrition, the elements 

 being the same in both cases. 



The organs of the flower, consequently, are considered in a state of 

 advancement, and that it requires some different power of the plant 

 to form the parts of the flower out of leaves, than is required to form 

 the ordinary leaves for nutrition. In any case, the floral organs are 

 considered to be removed from leaves in an ascending order, and the 

 highest pitch of development being concentrated in the formation of 

 the petals, not only in converting the green calyx into coloured or- 

 gans, but bringing back the stamens and carpellary leaves to petals, 

 or to that condition which apparently they had gone beyond. 



The metamorphosis of the normal condition of the organs of a 

 flower, is familiar to most persons in what is termed " a double flow- 

 er," in which there appears to be nothing but a mass of petals, the 

 other organs being employed in the formation of the monstrosity. 



The metamorphosis of. flowers appears to be of two kinds, centripe- 

 tal and centrifugal : that is, the organs from without inwards and 

 from within outwards, take the character of petals, the petals being 

 the imaginary organic centre, which does not alter its nature. 



Instances of both these kinds of metamorphosis are frequent among 

 cultivated flowers ; of the former may be mentioned the Polyanthus, 

 where the calyx assumes the character of the corolla ; and of the lat- 

 ter the double stock, double cherry, double Lychnis dioica, and mul- 

 titudes of other instances : in these, the several more internal organs, 

 as the stamens and pistils, become converted to the nature of petals. 

 The point I wish most to insist upon in the latter form of metamor- 

 phosis, is, that the carpellary leaves, which are employed in the for- 

 mation of the pistil (seed-vessel), are not always converted into petals, 

 but assume the green hue common to ordinary leaves. These, how- 

 ever, by the processes of horticulture, but chiefly by richer soils, can 



