On the Origin of the Perianth of Flowers. 45 
according to Eichler, four of the stamens, viz., the outermost ones, 
are conspicuously larger than the rest, and, moreover, alternate 
regularly with the four sepals (Fig. 5). Now, if we turn to the 
species C. balearicus (Atragenc calycina) the four large stamens of 
the last species are exactly replaced by four small petals (Fig. 6). 
Eichler observed in cultivated specimens of Atragenc alpina that 
not only were the four large stamens of C. integrifolia replaced by 
petals, but that also all the intervening stamens belonging to the 
same spiral cycle as the four large ones, as well as the whole of 
those of the next inner cycle, had become transformed into tiny 
petals; the four alternating with the sepals considerably exceeding 
in size any of the other stamens. 
Now what has here in Atragene alpina, been noticed as an 
abnormal phenomenon occurs normally and typically in Adonis 
vcrnalis where, to the 8 petals succeeding the sepals, and which are 
alone present in A. autumnalis, is added a second inner whorl of 8 
or, more frequently, a slightly larger number of petals (Fig. 7). In 
Adonis aestivalis and other annual species 6, 5, or even fewer petals 
are present; thus the remaining petals, which, in A . autumnalis make 
up the 8-merous character of the corolla, occur here as stamens. 
There seems, at least to our mind, little doubt in these cases as to 
the origin of the petals. Other similar cases could be cited. But 
what we have written is probably sufficient to demonstrate the origin 
of the corolla from the androecium. 
Let us now turn to the calyx and try to discover its region of 
birth. It is a striking and beautiful fact, as illustrating the division 
of labour that takes place in the economy of the flower in this group 
of plants, that in the absence of a double perianth, the single one 
(which, on the analogy of the flowers of the great generality of plants, 
must necessarily be regarded as a calyx) assumes the characters, 
viz., the colour and texture, of the corolla in the double perianth. 
Such a petaloid calyx is exhibited by Caltha, Trollius palmatus, 
Isopyrum (sect. Enemion,) Trautvetteria, Clematis sp., Anemone sp. 
(Fig. 9), Thalictrum sp., Hydrastis. As regards the generality of its 
species, Trollius is in this respect an interesting genus. Its corolla 
consists of small staminodial structures; the outermost of these 
have, on Celakovsky’s view, been transformed at some time or other 
in the past history of the plant into extra sepals, so that in T. 
europaeus, T. asiaticus, etc., the petaloid calyx, unlike its 5-merous 
counterpart in the white-flowered T. laxus, has become polymerous 
(Fig. 8). 
Now, we have to decide which is the more primitive: the 
ordinary green calyx of Ranunculus and the majority of Dicotyle¬ 
donous plants, or the petaloid calyx of the cases just mentioned. 
