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STRUCTURE OF THE FLOWER AND ITS ORGANS. 149 
all inserted on the receptacle, and the corolla and stamens 
are said to be hypogynous, that is, beneath-the-pistil. In I 
the petals and the stamens appear as if they had grown fast 
to the calyx for some distance, so that they surround the 
pistil, and they are therefore said to be perigynous, that is, 
around-the-pistil. In III all the parts are free or uncon- 
Fia@. 130. — Diadelphous 
Stamens of Sweet Pea. 
Fic. 129. —_Mona- 
delphous Stamens 
of Mallow. 
aoe | 
a 7 
(3 f) Fic. 131. — Stamens of 
- a Thistle, with An- 
A B C 
thers United into a 
Fic. 132. — Principal Types of Placenta. Ring. 
A, parietal placenta; B, central placenta; a, united anthers; /, 
C, free central placenta; A and B, trans- filaments, bearded 
verse sections ; C, longitudinal section. on the sides. 
solidated, except the petals and stamens; the stamens may 
be described as epipetalous, that is, growing-on-the-petals. 
Sometimes some or all of the other parts seem to grow out of 
the ovary, and such parts are said to be epigynous, that 1s, 
on-the-ovary, like the petals and stamens of the white water- 
lily, Fig. 134. 
186. Floral Diagrams.— Sections (real or imaginary) 
