. The origin of floral structures : through insect and other agencies. Plants; Flowers; Flowers. PHYLLODY OF THE FLORAL WHORLS. 305 Pistils -whicli have reverted to a more or less foliaceons character bear ovules whicli often become foliaceons as well; and then a not nncommon proceduro is the develop- ment of a cup-like structure, probably composed of the two ovular coats, on an elongated stalk, with a rudimentary nucellus within, but more or less perfectly free from it; or it may not exist at all. The late Professor Henslow described a monstrous con- dition of Mignonette with figures of ovule
. The origin of floral structures : through insect and other agencies. Plants; Flowers; Flowers. PHYLLODY OF THE FLORAL WHORLS. 305 Pistils -whicli have reverted to a more or less foliaceons character bear ovules whicli often become foliaceons as well; and then a not nncommon proceduro is the develop- ment of a cup-like structure, probably composed of the two ovular coats, on an elongated stalk, with a rudimentary nucellus within, but more or less perfectly free from it; or it may not exist at all. The late Professor Henslow described a monstrous con- dition of Mignonette with figures of ovules in this condition.* They were sometimes replaced by minute leaves (Fig. 85, c); or else in the place of each was a cnp-like structure, elevated on a long stalk, with an egg-like nucellus within, but quite free from it. He likened it to tbe theca of a pig. 55 Follaceous and metamorphosed ovulea of Mlgno- moss with its central °'"' ('"*' ^°^- â¢'â ^- Hensiow). columella. Comparing these two modifications, represented by Fig. 85, a and h with c,âor, again, those of Fig. 86, a and 6,âthe interpretation seems to be that the fibro-vascnlar cord passing up the funicle of the omle becomes a petiole, and its prolongation constitutes the mid-rib. The secundine and primine with intermediate tissue become the blade, as seen in the foliaceous states of ovules, and constitute the " cup " when they assume that form. A similar process, I think, quite explains the origin oE tbe foliaceous processes of the stamen of Jatropha, repre- sented by Fig. 84. The entire stamen is, of course, really * Trans. Camh. Phil. Soc, vol. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Henslow, George, 1835-1925. New York : Appleton
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Keywords: ., bookcentury1800, bookdecad, booksubjectflowers, booksubjectplants
