208 . THE AMERICAN NATURALIST. [Vor. XXXVI. 
R. viridiflora is green, with scarlet edges. In R. auricomus the 
petals are sometimes wanting, and ‘their place is taken by 
the sepals with their bright yellow limb. . In Ficaria ficaria 
(R. ficaria) the ‘petals are yellow, or red fading whitish. The 
white flowers of Batrachium, or water crowfoot, show that they 
are descended from ancestral yellow forms by retaining vestiges 
of this color as honey guides at the base of the petals. The 
cultivated Adonis annua, or pheasant’s eye, has showy orange 
or red flowers, to which the black anthers offer a marked con- 
trast. The most highly specialized regular flowers of this family 
belong to Aquilegia, or columbine: They may be regarded as 
the culmination of the buttercup type. The sepals are regular 
and petaloid, while the petals are prolonged backward into a 
hollow spur. The intermediate stages between the nectariferous 
pit of the buttercup and the hollow petal of Aquilegia are 
excellently shown in the extremely variable petals of A. auri- 
comus: - Aquilegia canadensis produces scarlet flowers, which 
are yellow inside and rarely all over, or occasionally they are 
white. There are two other species in the northern flora which 
exhibit a similar coloring, Lonicera sempervirens and Spigelia 
marylandica, and the former is sometimes. yellow throughout. 
A. canadensis is visited by bumblebees and humming birds. The 
European A. vulgaris is blue, purple, or white. 
The two zygomorphic genera, Delphinium and Aconitum, are 
the most recent in their origin, and represent the highest stage 
of development. attained by the Ranunculacezm. The sepals are 
petal- like... The flowers are blue or revert to white, or, in Acozz- 
tum reclinatum, are regularly white. High specialization, polli- 
nation by bees, and. probably blue color, are here correlated. 
Masters gives an instance in Delphinium peregrinum of perfectly 
regular flowers having five sepals and five oblong stalked petals, 
and also in oe the tubular petals may be repoa by flat 
.ones. 
At oe period ie insects began to visit the y S of the 
Ranunculacez, the different genera were in a transition state 
and only partially. differentiated. It is evident that one effect 
of their visits was to flowe . This result 
ONCE Ts SP F 
has been reached in different v ; in tl i geni era, according 
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