Text-book of botany, morphological and physiological . planes, Fig. 376 by four, and Fig. 377 by five diagrams Fig. 378 B and C, as well as Fig. 379, can, on the contrary, be symmetri-cally halved by only one plane, which is at the same time the median plane. The diagramFig. 380 can be divided by the median plane into two symmetrical halves which are 534 PHANEROGAMS. unlike those produced by the hiteral section; this diagram is, hke those in Figs. 378ii, Cand 379, zygomorphic, but is doubly while these are only singly symmetrical. The symmetry of mature unfolded flowers is indeed us
Text-book of botany, morphological and physiological . planes, Fig. 376 by four, and Fig. 377 by five diagrams Fig. 378 B and C, as well as Fig. 379, can, on the contrary, be symmetri-cally halved by only one plane, which is at the same time the median plane. The diagramFig. 380 can be divided by the median plane into two symmetrical halves which are 534 PHANEROGAMS. unlike those produced by the hiteral section; this diagram is, hke those in Figs. 378ii, Cand 379, zygomorphic, but is doubly while these are only singly symmetrical. The symmetry of mature unfolded flowers is indeed usually connected geneticallywith the relations of symmetry of the diagram (which represents only the position andnumber of the parts); as will be made clear by a comparison of Pigs. 385 and 387 withFig. 379 ^. But inasmuch as the entire form of the mature flower is essentially deter-mined by the shape, size, torsion, and curvature of the separate parts, these circum-stances also exert a preponderating influence on the relations of symmetry of the open. —Zygomorphic flower of Cohantica Schiedeana : A entire flower after removal of two sepals ; E andruecium ;C gynasceum ; D the coherent anthers magnified and seen from behind ; E horizontal section of the ovary ; F diagram ;a anthers, n stigma, g style, fk ovary, d the stamiiiode developed into a nectary, // the lateral oblique placentae. fower, and to such a degree that even flowers that have their parts arranged spirallymay become monosymmetrically zygomorphic in reference to their entire form, as isthe case to a high degree, for example, in Aconitum and Delphinium. It must howeverbe observed that the zygomorphism of the flower is here brought about principally orentirely by the calyx and corolla, the spiral arrangement of which may perhaps still bedoubtful, but which always occupy so narrow a zone on the receptacle that their positionmay be considered practically to be verticillate. If, on the other hand, the floral ax
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectbotany, bookyear1875
