44 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



and no true petals are formed, the calyx being white or taking on 

 some colour for insect-attraction. 



In Atragene, allied to the Clematis, which has no corolla, the outer- 

 most stamens have developed a honey-groove down the filament, and 

 this now broadens into a petal. A similar transformation is seen in 

 the Water-lily : the perfect stamens are next to the pistil ; on others, 

 the anthers decrease and the filaments widen till perfect petals are 

 secured. 



Carpels, such as a pea-pod, are more obviously metamorphosed 

 leaves, being folded along the midrib with the margins meeting, 

 cohering, and bearing ovules, really in two rows, one on each margin. 



As to the origin of ovules, some abnormal foliaceous conditions 

 of flowers reveal the fact that they are homologous with little foliar 

 or leaf-like excrescences from the vascular cords of the leaf, which 

 often give rise to little cups or funnel-like structures, as well as 

 fiat leaflets. Such have occurred in monstrous " flowers of the 

 Mignonette and some leguminous plants, &c. 



Nature having thus evolved a simple flower, as of a Buttercup, 

 in which all the parts are " free," the next step in adaptation to 

 insect-visits is to unite the parts of one or more of the floral whorls 

 respectively, by " cohesion." We thus get a cup-like calyx, this 

 word being the Latin for a " cup," The purpose is often to support 

 the corolla when the petals cohere and form a slender tube below. 



It is the case especially when the corolla has a weak tube, but a 

 large " lip " for a landing-place. To strengthen the calyx-tube, 

 the original midribs of the leaves are supplemented by others inserted 

 up the coherent edges, as in Labiates. As the number of sepals 

 in this family is five, we now have ten ribs ; but as the strain is all 

 on the front of the corolla— i.e. on the lip — Nature adds three pairs of 

 ribs, one pair on each side, and a third in front, but none at the back. 

 They thus make thirteen strengthening ribs. In Salvia, however, 

 which has a particularly large lip, a fourteenth rib is inserted between 

 the additional front pair. 



This example illustrates only one addition ; but a flower of a 

 Salvia has twenty or more special adaptive structures, and the only 

 interpretation seemingly possible is that of Sir Oliver Lodge, who 

 says " Life is a Director of Forces " ; so that it responds to all kinds 

 of external influences by directing the inanimate, physical forces 

 utilized to move inanimate matter (both matter and force being 

 derived from food) so as to build up the purposeful structures required 

 in every case. 



In this way we seem to trace the origin of all kinds of floral 

 structures, and thence the origin of varieties and species which are 

 founded upon them. 



