38 THE STKUCTUEE OF FLOWERS. 



be seen by comparing the nnmber of stamens in a large- 

 flowered form of Banunculus aquatilis, with the small- 

 flowered Bi. hederaceus ; or one genus with an allied one, as 

 Ranunculus with Myosurus, in which the stamens are reduced, 

 often to one whorl of five only. 



Lastly, just as high spirals can be broken up into ternary 

 whorls, so can the arrangement ^^y be separated into whorls 

 of a lower series, as of 13, 8, or 5 parts respectively. Thus, 

 of the two genera, which have opposite leaves, comprising 

 the order GalycantJiacece, Galycanthus illustrates an abrupt 

 change from opposite leaves to the -j^ arrangement in the 

 bract-like sepals of the flower; but no distinction between 

 bracts, sepals, and petals can really be made. Ghimonanthus, 

 however, would seem to be a more highly difEerentiated type, 

 in that, not only is the calyx distinguishable f A)m the corolla, 

 but five exterior stamens constitute a distinct whorl by them- 

 selves, and the indefinite barren ones of Galycanthus are here 

 reduced to five ; so that, omitting the pistil, the flower con- 

 sists of four distinct pentamerous whorls. 



