Journal of botany, British and foreign . wherestyles and stigmas would, under ordinary circumstances be de-veloped. The ovarian character of the anther-bearing cup wasfurther ascertained by my friend Eev. Prof. Henslow, who tracedin the anther-bearing cup the vascular cords corresponding to those. AN EERATIC IVY. 178 which constitute the midribs of the carpels of the normal accompanying cut, Fig. 2 (p. 174), which has been kindly placedat my disposal by that gentleman, and which is taken from hisrecently published work on the Origin of Floral Structures,illustrates the arrangement a
Journal of botany, British and foreign . wherestyles and stigmas would, under ordinary circumstances be de-veloped. The ovarian character of the anther-bearing cup wasfurther ascertained by my friend Eev. Prof. Henslow, who tracedin the anther-bearing cup the vascular cords corresponding to those. AN EERATIC IVY. 178 which constitute the midribs of the carpels of the normal accompanying cut, Fig. 2 (p. 174), which has been kindly placedat my disposal by that gentleman, and which is taken from hisrecently published work on the Origin of Floral Structures,illustrates the arrangement and distribution of the fibro-vascularcords in the pedicel and ovary of the Ivy under ordinary circum-stances. In the pedicel there are four such cords as indicated insection at a; at a higher level these four divide, and the divisionsare arranged in a ring or circle, as seen on a transverse section b;at the base of the receptacular tube fifteen such cords may be seenc, ten in one outer ring, five in an inner series ; the outer ten pass. Fig. 1.—Abnormal flower of Ivy seen from the top, the side, and in medianVertical section. To the left is seen an abnormal stalked flower, which occupiedthe centre of one of the flowers. upwards, one into each of the five sepals and five petals respectively;the inner five are separated radially from those cords which aresuperposed to the sepals and are destined to supply the from the five cords of the outer series which supply thepetals two divisions are given off, of which one runs up the centreof each carpel, and the other up the axis, d. If only four or threeovarian cells are developed, then the central cords become fused 174 AN ERRATIC IVY. into four or three, alternating with the ovarian cavities e, ultimatelydividing, so as to form twice as many cords as there are ovariancells, some divisions supplying the ovules,/, the others passing intothe styles. Assuming this presentation of the facts to be correct, the ex-planation of
Size: 1260px × 1983px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthortri, bookcentury1800, bookdecade1860, booksubjectplants
