On the examination of a hybrid digitalis / by J.S. Henslow.

  • John Stevens Henslow
Date:
1831
Catalogue details

Licence: Public Domain Mark

Credit: On the examination of a hybrid digitalis / by J.S. Henslow. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    obtained by tearing the ovarium asunder down the thickness of the dissepiment, which is composed of two skins with parenchy- matous matter between them. The threads of vascular tissue arranged in a circle round the axis of the pedicel («), after giving otf veins to the calyx and corolla {b), and again to the pericarp {c), diverge on either side into the placenta {d), a little above its lowest point, and then ramify or subdivide through its substance into separate fibres {d) which proceed directly to the bases of the ovules. Fig. 3. represents a transverse section of the upper part of the ovarium with the lower part of the style ; the valve which is nearest the spectator being removed, as also are the ovules in this cell. The smaller veins (c'), of which more than twenty are seen rising through the pericarp, all terminate in the base of the style ; but the two larger ones (c), which run along the loculicidal edge of the pericarp, rise through the whole length of the style. The stigmatic tissue (e), (Fig. 1. 2. 3.) de- scends down the middle of the style till it comes into contact with the summit of the placenta. When the appearances here represented are examined with the highest magnifiers, their more intimate structure is exposed, as in Plate xviii. where Fig. 1. and 2. are two transverse sections of the pistil, of which the former corresponds to one quarter of the circumference of the ovarium represented in the lower part of Fig. 3. Plate xvii., and the latter agrees with the section through the style in the upper part of the same figure. Plate xviii. Fig. 3. and 4. are longitudinal sections of the same organ, the former through the stigma, the latter through the summit of the ovarium where the stigmatic tissue {e) descends to the placenta, as in Fig. 1. Plate XVII. In these highly magnified sections all the corresponding parts are designated by the same letters as in the former figures.
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