466 DR. M. T. MASTERS ON THE SUPEBPOSEO 



The arrangements in Lardizabala and Holbcellia, 



S 



and Eirimedium, 



P 



St, 



8 



P 

 P 



St, 



may be attributable to the same cause or to chorisis*. 



2. Spiral arrangement of parts. — In these cases the calyx forms a 

 complete cycle followed by the corolla in the same manner. An 

 illustration of this may be seen in the case of Sabia, wherein the 



2 



sepals of the calyx are arranged on the - plan, and the petals 



5 



first 



superposed to the second sepal, and so forth. Such flowers would 

 fall under A. Braun's definition of hemicyclic. It may be well in 

 this place to allude, in passing, to Payer's explanation of the pas- 



sage of the decussate arrangement into the ^ plan by the mere 



chorisis of one leaf, and to the views of the Eev. G-eorge Henslow 

 (Trans. Linn. Soc. 1875, Botany, i. p. 37). The latter author de- 

 duces the spiral arrangement from opposite and decussate leaves. 

 3. JZnation, Chorisis. — By Pfefter t the petals of primroses are 

 supposed not to be autonomous organs, but outgrowths from the 

 stamens ; hence the superposition of the latter to the former. The 



M 1 j ft OlI -m _- ^h a 



Monotheca 



My: 



? 



with their rows of abortive stamens, by means of which the sym- 

 metry is restored, is contrary to the view advocated by Pfeffer. 

 Again, though it is true that in young buds the stamens are seen to 



In some double varieties of Columbine (Aquilegia) grown in gardens from 

 time immemorial, there is true superposition, the tubular petals being not only 

 multiplied but ensheathed one within the other, or as the French say " emboites," 

 like a M nest " of pill-boxes. There are other varieties in which petals are either 

 not present or wherein they are represented by flat sepals arranged in like 

 manner as in the Starry Columbines of the older writers, so called because the 

 leaves of the flowers do stand so directly one by another. Where the over- 

 lapping is only partial, the term Rose Columbine is given (see Parkinson, .'Pa- 

 radisus,' p. 272). 



t In PringsheinVs Jahrbuch, vol. vii. p. 194. 



