206 THE AMERICAN NATURALIST. [Vor. XXXVI. 
support.. The Magnolias are stately trees, growing in rich 
woodlands. Both families have very large leaves. The primitive 
color of the flowers»was probably green, as it still is in Magnolia 
acuminata, ‘Transition stages from green to yellow occur both 
in Liriodendron and in Wymphea advena. In other instances, 
as in certain species of Magnolia and Castalia, they became 
white at a very early stage, and in certain species subsequently 
changed to red. In the case of M. macrophylla, where the 
white flower has a large purple center, the entire flower may 
have been purple, as in ///ictum floridanum, or anise tree, or it 
may be a deposit of pigment resembling that found on the inner 
side of the sepals of Vymphea advena. 
In a part of the species of the Ranunculacez the petals are 
wanting ; in a part they are small and transformed into hollow 
nectaries; while in others they are regular and conspicuous. 
The ancestral stock from which the various genera have diverged 
doubtless possessed petals, or phyllomes, corresponding to this 
whorl; but they had already been lost by some generic lines 
when insects began to visit the flowers. Of the ninety-seven 
species, six aré green, twenty-six are white, thirty-eight are 
yellow, three are red, thirteen are purple, and eleven are blue. 
Conspicuousness is insured by the sepals in Clematis and 
Caltha; by the petals in Ranunculus; by both the petals and 
sepals i in Aquilegia ; and by the numerous stamens in Thalictrum, 
Actzea, and Cimicifuga. In Thalictrum the white or lilac fila- 
ments are broad and petaloid. The flowers are visited infre- 
quently by flies and the short-tongued bees. 
Of the apetalous flowers, Caltha palustris and C. flabellifolia 
have a yellow, and the aquatic C. natans a white, calyx. A 
change of locality may induce a change from yellow to white, 
as Anemone alpina on the Central Alps bears chiefly sulphur- 
yellow flowers, but in the eastern limestone Alps its flowers 
are always white. In our native species of Anemone the sepals 
are green, white, or purplish, but florists offer scarlet and blue 
varieties. The anthocyanin displayed by the underside of the 
sepals of A. nemorosa, especially in bud, probably serves to con- 
vert light rays into heat ; this plant blooms in early springtime. 
The sepals of Clematis ochroleuca are green, of C. virginiana 
