174 THE FLOWER. 



stamen of a species of Water-Lily (Nymphsea Lotus) is figured 

 and described by Dr. Masters. 1 



314. In the application of morphological ideas to the elucida- 

 tion of the flower, nothing should be assumed in regard to it 

 which has not its proper counterpart and exemplar in the leaves 

 and axis of vegetation. 



SECTION II. FLORAL SYMMETRY. 



315. The parts of a flower are S3*mmetrically arranged around 

 its axis. 2 Even when this S3 r mmetry is incomplete or imperfect, it 

 is still almost always discernible ; and the particular numerical 

 plan of the blossom may be observed or ascertained in some of 

 the organs. 



316. Adopting the doctrine that the parts of the flower are 

 homologous with leaves, the symmetry is a consequence of the 

 phyllotaxy. It is S3 T mmetr3' around an axis, not the bilateral 

 symmetry which prevails in the animal kingdom. For parts of 

 a flower disposed in a continuous spiral (which mostly occurs 

 when they are numerous) , the arrangement is that of some order 

 of this kind of phyllotaxy, which distributes the parts equably 

 into superposed ranks. (237.) The much commoner case of 



1 The fullest enumeration and discussion of the very various kinds of 

 abnormal structures and deviations in plants is to be found in the Teratology 

 of Dr. Masters, above referred to. Many technical terms are here brought 

 into use, which need not be here mentioned, except the following, which relate 

 directly to floral metamorphosis. 



Phyllody (called Phy/lomorphy by Morren, Frondescence by Engelmann) is 

 the condition wherein true leaves are substituted for some other organs ; 

 i. e., where other organs are metamorphosed into green leaves. There is 

 phyllody of pistils, ovules, filaments, anther, petals, sepals, &c. 



Sepalodi/, where other organs assume the appearance of green sepals. 



Petalody, where they assume the appearance of petals, as normally in 

 Pinckneya and Calycophyllum, in which one calyx-lobe enlarges and becomes 

 petal-like, and abnormally in Primroses where all the calyx-lobes imitate 

 lobes of the corolla (this has been termed Calycanthemy) ; also of the stamens 

 of common " double flowers." 



Staminody, where other organs develop into stamens. Cases of this as 

 affecting pistils are referred to above : rarely sepals and petals are so affected. 



Pistillody, where other organs develop into pistils, which most rarely 

 happens except with the stamens, as above mentioned. 



2 It is stated that Correa de Serra (who published botanical and other 

 papers in London, Paris, and Philadelphia during the first twenty years of 

 the century, but who knew far more than he published) was the first botanist 

 to insist on the symmetry of the flower. It was first made prominent by De 

 Candolle, in the Theorie Elementaire, and elaborated in detail by A. St. 

 Hilaire in his Morphologie Vegetale. 



