On the Origin of the Perianth of Flowers . 47 
Now consider the very striking case of A. japoiiica or of A. 
stellata. Here, to the original and primitive 5-merous calyx, a 
considerable number of members have been added, so that the 
perianth frequently consists of as many as twenty sepals, 1 and it is, 
moreover, clear that these have been added from the stamens, by 
metamorphosis of the latter, for, in the centre of the flower, transi¬ 
tional forms between stamens and sepals are always present and we 
receive, as it were, ocular demonstration of the method of pro¬ 
duction of these sepals which from without inwards form a con¬ 
tinuous spiral of similarly-constituted petaloid leaves (fig. 10). But 
the most important fact has yet to be stated. In A. japoiiica two or 
three of the outermost sepals (as is also the case in Trollius ) are 
always slightly differentiated from the rest, owing to their having, 
in whole or in part, a somewhat darker, purplish coloration, 2 and 
occasionally they exhibit a decidedly greenish tinge. Now, in that 
section of the genus known as Knowltonia (exhibiting also a poly- 
merous calyx) these two or three outermost sepals are entirely green 
and bract-like. Prantl accounts for the polymerous perianth of these 
forms by assuming that the single perianth of other species (which, 
on his view, is of bracteal origin), first multiplied its parts and 
subsequently became differentiated, as regards colour and texture, 
into two distinct portions. But, as Celakovskv aptly suggests, this 
multiplication could hardly have taken place ex nihilo ; on the con¬ 
trary, the extra sepals must necessarily have been derived by 
metamorphosis of the stamens; and further, if the perianth be 
originally of bracteal derivation it would seem strange that single 
perianths of a green bract-like consistence are of such rarity in the 
order. But, as regards this, and all other questions bearing on the 
subject of this article, we leave our readers to judge of the respec¬ 
tive value of the theories of the two authors whose names have been 
chiefly introduced. Yet after all the impressive facts above detailed 
it seems to our mind fairly clear that in the great order Ranun- 
culaceae, calyx and corolla have sprung from the self-same source, viz. 
the andrcecium ; that they constitute one and the same morphological 
structure, which, following the economic needs of the plant, appears 
now as green protective leaves, now as brightly-coloured, delicately- 
textured organs for the allurement of insects which are the destined 
agents in the fertilization of the flower. 
And if this be the history of the evolution of the perianth in 
the group of plants we have been considering, it is surely but 
1 The same phenomenon exists normally in the genus Clematis . 
in such species as C.fiorida and C. patens where the calyx 
may consist of as uianj’ as ten sepals. 
2 I11 the polymerous calyx of A. rivularis we have noticed that 
the five outermost sepals are of a dark purple colour below. 
