THE SHAPES OF FLOWERS. 147. 



found some in which conformity to the general Liw is not 

 obvious. The discussion of these apparent anomalies would 

 carry us too much out of our course. ^ A clue to the explana- 

 tion of them will, I believe, be found in the explanation 

 presently to be given of certain kindred anomalies in the 

 forms of individual flowers. 



§ 233. The radially-symmetrical form is common to all 

 individual flowers that have vertical axes. In plants which 

 are practically if not literally uniaxial, and bear their flowers 

 at the ends of upright stalks, so that the faces open hori- 

 zontally, the petals are disposed in an all-sided way. Cro- 

 cuses, Tulips, and Poppies are familiar examples of this struc- 

 ture occurring under these conditions. A Ranunculus flower, 

 Fig. 228, will serve as a typical one. Similarly, flowers 

 which have peduncles flexible enough to 

 let them hang directly downwards, and 

 are not laterally incommoded, are also 

 radial ; as in the Fuchsia, Fig. 229, as 

 in Cyclamen, Hyacinth, &c. These rela- 

 tions of form to position are, I believe, 

 uniform. Though some flowers carried at the ends of up- 

 right or downright stems have oblique shapes, it is only when 

 they have inclined axes or are not equally conditioned all 

 round. No soKtary flower having an axis habitually ver- 

 tical, presents a bilateral form. This is as we should expect, 

 since flowers which open out their faces horizontally, 

 whether facing upwards or downwards, are, on the average, 

 similarly afi'ected on all sides. 



At first it seems that flowers thus placed should alone 

 be radial ; but further consideration discloses conditions under 

 which this t}^e of symmetry may exist in flowers otherwise 

 placed. Remembering that the radial form is the primitive 

 form — that, morphologically speaking, it results from the 

 contraction into a whorl, of parts that are originally arranged 

 in the same spiral succession as the leaves ; we must expect 



