360 Botanical Society of London. 



Mr. John Thompson presented specimens of Carex irrigua (Smith), 

 collected by him in Northumberland. 



Mr. T. Twining, Jun., exhibited a large collection of cultivated 

 specimens from Twickenham. 



Read, the continuation of a paper from Mr. R. S. Hill, being "An 

 Inquiry into Vegetable Morphology." Irregular metamorphoses of 

 flowers are extremely common, and usually consist either of an actual 

 multiplication of petals, or of the transformation of stamens and 

 pistils into petals ; the effect of these changes being the formation of 

 double flowers, the impletion of which appears to take place in dif- 

 ferent ways in different plants. In most Icosandrous and Polyan- 

 drous plants, impletion appears to result almost entirely from the 

 conversion of the stamens, and in some instances of the pistils, into 

 petals ; in the double varieties of Ulex europaus it results from the 

 same change. In Oligandrous plants we usually find an actual mul- 

 tiplication of petals, as may be seen in the double stocks and wall- 

 flowers of our gardens. Where the impletion is the result of this 

 alteration of the essential floral organs, the plants are necessarily 

 barren. Such, however, is not the case with the dahlia, aster and 

 other plants, which belong to the Corymbiferous section of Compo- 

 site; in these the impletion results, first, from the change of the 

 tubular florets of the disc into ligulate florets, the same as those of 

 the ray, as in the dahlia ; and secondly, by simple enlargement and 

 elongation of the tubular florets, as in the many varieties of the China 

 aster. Such monstrosities, from the fact of the essential organs not 

 being in any way implicated, are capable of perfectly impregnating 

 their ovules. Thus a knowledge of the mode in which impletion 

 occurs is of importance to the gardener, in order that he may be en- 

 abled to calculate on the possibility of producing new varieties by 

 seed. 



Dr. Lindley says, that " these changes always occur in the order 

 of development, or from the circumference to the centre ; that is to 

 say, that the calyx is transformed into petals, petals into stamens, 

 and stamens into ovaria ; but that the reverse does not take place." 

 In proof of this hypothesis he further says, " that if the metamor- 

 phosis took place from the centre to the circumference, or in a di- 

 rection inverse to the order of development, it would not be easy to 

 show the cause of the greater beauty of double flowers than of single ; 

 because the inevitable consequence of a reversed order of transforma- 

 tion would be, that the rich or delicate colour of the petals, upon 

 which all flowers depend for their beauty, would be converted into 

 the uniform green of the calyx. Such a change, therefore, instead 

 of increasing the beauty of a flower and making it superior to its 

 original, would tend to destroy its beauty altogether." Now, were 

 this hypothesis correct, and founded on fact, what ought to be the 

 condition in which we find the organs in double flowers ? We ought 

 surely to find the centre of the flower filled up with an increased 

 number of pistils. But is this the case? It is plain it is not; in- 

 deed, were it the case, the beauty of a double flower would be most 

 effectually destroyed. This theory must therefore fall to the ground, 



