INTRODUCTION 
degree, i.e. in the ovarian region only, in the base or the whole of the 
stylar region also, or throughout. Thus the two carpels of Saxifrages are 
only united by the lower part of their ovaries, which are two-chambered : 
the St. John’s-worts have generally three carpels united into a three- 
chambered ovary, but with three separate styles : in Violets the three 
carpels are united throughout, so as to have but one ovary, style, and stigma; 
but, the margins of the carpellary leaves meeting without being inrolled, 
there is only one chamber to tbe ovary, the three placentas being on its 
side walls ( parietal ), instead of forming a central column, as in the St. John’s- 
worts. In some cases the ovules arise from the base of a one-chambered 
ovary, which may be formed by one or more carpels ; or from a central 
placenta, which is free, i.e. has no apparent partitions connecting with the 
side walls of the ovary ; or even from the general inner surface of the 
ovary. Thus we have what is termed parietal placentation in the Violet, 
central placentation in the St. John’s-wort, basal placentation in the Composite, 
free central placentation in Pinks and Primroses, and superficial placentation in 
Poppies and Water-lilies. 
The number of carpels in a syncarpous ovary may be determined 
externally, by lobing, as in the Lily, or by the number of styles, or by the 
number of chambers seen in a cross-section ; but, besides the partitions or 
septa formed by the inrolled margins of the carpellary leaves, various false 
septa occur, either ingrowths of the midribs of the carpels, as in Flax and 
Poppies, or longitudinal or transverse ingrowths from the placentas, as in 
the Crucifera , in the Milk-vetch ( Astragalus ), etc. 
An important character is whether the ovary is superior , i.e. free from 
all adhesion to the receptacular tube, as in Lilies, Primroses, Heaths, or 
Nightshades, for examples ; or inferior , i.e. enclosed within this tube and 
thus appearing prominently below the calyx, as in Daffodils, Whortle- 
berries, Gooseberry, and all Composite c and IJmbelliferce. 
The style may be absent, as in Poppies, when the stigma becomes 
sessile. Though generally springing from the apex of the ovary, or 
terminal , it may be lateral , as in the Strawberry, or may rise from the 
depressed centre of a ring of carpels, when it is termed gynobasic. It is 
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