Ficaria verna , arid other Members of the Ranunculaceae. 75 
the flower (e.g. A. palmata ), we find that the involucral leaves partake of 
the dissected, probably ancestral, foliar type and do not resemble the simple 
foliage of the species — a fact that cannot be explained on any other 
hypothesis than the common origin, and therefore phylogeny, of both bracts 
and foliage. 
In Ranunculus acris Goebel (1905, p. 393 ) was struck by the unusual 
condition that the hypsophylls were more divided than the foliage leaves, 
and we have already noted the same feature exhibited by Ficaria verna. 
Again, on the foliar theory we should naturally expect to find the 
involucre of upwardly displaced leaves more closely approximated to the 
flower the more specialized the floral structure. In the genus Nigella the 
different species show various degrees of fusion between the carpels ; in 
N. arvensis the carpels are only slightly joined, whilst in N. damascena the 
fusion is complete. In the former the involucre is remote from the flower, 
in the latter closely approximated to it. 
If we accept the view that this involucre is directly derived from 
sporophylls then we have the anomaly of the least specialized involucre 
associated with the most specialized gynaeceum and vice versa. 
There can be little doubt that the involucres of Anemone , Eranthis , 
and Nigella are homologous structures, and there are no adequate grounds 
for regardingthe involucre of A. hepatica as distinct in origin from the calyx 
of Ranunculus ficaria. 
Various writers have pointed out that the Ranunculaceae present us 
with almost all stages in the development of petaloid stamens, from the 
nectariferous staminodes of Anemoiie pulsatilla to the petal of Ranunculus . 
If we hold that the perianth is entirely staminodal (cf. de Candolle, 
1823 ; Drude, 1887 ; Celakovsky, 1896 and 1900 ; Worsdell, 1903) then we 
must assume that two totally uncorrelated lines of evolution from the same 
type of structure are presented to us. For in Ranunculus or any of the 
Helleboreae we must assume that, first, the non-nectariferous perianth was 
developed from the sporophylls and that subsequently from the same origin 
a completely distinct type, the nectariferous petal, became elaborated. 
Moreover, there is no relation between the specialization of the non-nectari- 
ferous perianth and the development of the honey-leaves. In Anemone 
pulsatilla we find a highly specialized coloured perianth, together with the 
simplest type of nectar-secreting staminode, and in the Helleboreae the 
more advanced type of flower of Helleborus has a less specialized honey- 
leaf than Eranthis. 
If we now turn to the mode of arrangement of the perianth segments 
we find that in the Clematideae the calyx usually consists of four members 
(arising as two pairs, cf. Payer, 1857, p. 252 ) corresponding to the four 
orthostichies of the decussately arranged leaves of the adult plant. In the 
other tribes, where the leaves are alternate and generally exhibit a one-third 
