204 THE AMERICAN NATURALIST. [VoL. XXXVI. 
leaves destined to form petals, sepals, and bracts. No such 
inflorescence now exists, but an approach to it may be found in 
the Magnoliaceze. In Magnolia the floral bud terminates the 
secondary branches, of which it is only a prolongation. The 
oblong flower of the Magnolia has the receptacle prolonged and 
the parts of the perianth, the stamens, and the pistils, spirally 
arranged and indefinite in number. In the arrangement of the 
plant families in a lineal series, those flowers which have the 
organs separate and which resemble most closely the proangio- 
spermous floral branch are regarded as the simplest; while the 
highest rank is assigned to those which have the organs modified 
and consolidated, as in the Orchidaceze and Compositze. 
In the Nymphzacez, or water lilies, we meet with dicotyledo- 
nous plants resembling monocotyledons in the structure of 
the leaf and rootstock. The analogous arrangement of the fibro- 
vascular bundles in a Nymphaea and a Tradescantia has been 
excellently figured by De Bary. The successive steps in which 
simple and distinct carpels may become compounded are also 
well shown by the genera of this family. In the primitive genus 
Nelumbium, also in the oldest forms found in a fossil condition, 
the simple carpels are contained in little pits in the large fleshy 
receptacle ; in Cabomba and Brasenia the oblong carpels are 
borne on the receptacle, but are separate ; in the fossil genus 
Anoectomeria of the Middle Tertiary the carpels are partially 
united ; in Nymphza the union is complete ; and finally, the 
culmination is reached in Victoria regia, where the compound 
ovary is inferior. Of the eleven northern species four are white, 
five yellow, one red, and one purple. Yellow coloring was 
probably very early developed, as it is the color of the primitive 
` Nelumbo lutea and of the three native species of Nymphza 
(Nuphar). Throughout the summer the numerous broad shin- 
ing leaves and large yellow flowers of Nymphaa advena, the large 
yellow pond lily, form a well-known characteristic in the vegeta- 
tion of ponds and slowly moving streams. The six sepals are 
unequal : the three inner are large and bright yellow; the three 
outer and smaller are wholly or partially green exteriorly, though 
the upper half is often yellow, while the interior lower portion 
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