40 AUSTRALIAN BOTANY. 



considered superior in point of beauty to single flowers of 

 the same kind, they are inferior to them from a botanist's 

 point of view, since they are in reality deformities. A 

 double flower is produced by the conversion of the inner 

 whorls — the stamens and pistil — into parts resembling the 

 outer ones. The more completely this is effected by cross- 

 ing, the more double the flower becomes, but the less capable 

 of producing seed, from the fact that the nature of its 

 fertilizing organs has been completely changed. Hence 

 double flowers, termed ' sports ' by gardeners, are con- 

 sidered unnatural by botanists. Double flowers, however, 

 are sometimes reproduced from seeds, but this cannot be 

 accomplished unless some of the fertilizing organs are perfect. 

 The following are the parts of a perfect flower : — 

 The calyx or fiower-cup (Plates IV. and V. cd) is the 

 outer floral envelope. It is usually, though not always, 

 green. In some flowers it is small, in others large ; and in 

 some — as in the true Fuchsia — coloured. In the native 

 Fuchsia it is green. A perfect calyx consists of one or 

 more pieces called sepals. In Plate IV. the calyx is in one 

 piece, therefore it has but one sepal, and is termed mono- 

 sepalous. In Plate V. the calyx is divided into four sepals, 

 hence it is polysepalous or ' many-sepaled.' The margin 

 of a calyx may be altogether or nearly entire, as in Plate IV., 

 or deeply divided, as in Plate V. A divided calyx may 

 be notched, toothed, or deft. In some plants the calyx falls 

 off soon after the flower opens. In others it remains, 

 becoming inflated (as in the skin of the currant) or else 

 fleshy. In gum-trees {Eucalypti) the calyx opens by the 

 upper part falling off in the shape of a cap or lid, called an 

 operculum. 



