. The origin of floral structures : through insect and other agencies. Plants; Flowers; Flowers. 306 THE STRUCTUKE OF homologous with one leaf alone; but the membranes belong- ing to each anther, being of, at least, two layers of cells, have become foliaceons, just as the epidermis of the nucellus has done in the cases herein described; so that, in the Jatropha, two leafy expansions were developed out of one. Other instances are known of ovules being represented by leaves, as Primula Sinensis, Synvphytum officinale,* and Sisymbrin/m Alliaria (Fig. 86). Theoretically, it might be obje
. The origin of floral structures : through insect and other agencies. Plants; Flowers; Flowers. 306 THE STRUCTUKE OF homologous with one leaf alone; but the membranes belong- ing to each anther, being of, at least, two layers of cells, have become foliaceons, just as the epidermis of the nucellus has done in the cases herein described; so that, in the Jatropha, two leafy expansions were developed out of one. Other instances are known of ovules being represented by leaves, as Primula Sinensis, Synvphytum officinale,* and Sisymbrin/m Alliaria (Fig. 86). Theoretically, it might be objected that a leaf (carpel) should give rise to a leaf (ovule or, at least, ovular coat) ; but foliaceous excrescences from a leaf- Fig. ovules surface are not at all uncommon, as, ^r'Sr^romtt for example, fi-equently occur in Cab- lum, xTii., t. 20). bages,f where, in consequence of high nourishment inducing hypertrophy, any " rib " or " vein " may throw off a branch which can form a leafy expansion, which not at all infrequently becomes funnel-shaped, like the abortive ovules of the Mignonette. Similar funnel-shaped or tubular productions are found on corollas of semi-double flowers, as in Primulas, Cyclamens, Antirrhinum, etc., sometimes externally. Fig. 87 represents a like out- cence'on the labeiium of growth from the labellum of Gattleya * "â MossieoB; and I have seen the posterior sepal of Vanda coerulea replaced by a pedicel with a cup at the apex exactly like the terminal process in Fig. 85, a. In all these cases I would regard such productions as due to 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
