The origin of floral structures through insect and other agencies . ssor Henslow described a monstrous con-dition of Mignonette with figures of ovules in this condition.*They were sometimesreplaced by minuteleaves (Fig. 85, c) ; orelse in the place ofeach was a cup-likestructure, elevatedon a long stalk, withan egg-like nucelluswithin, but quite freefrom it. He likenedit to the theca of amoss with its centralcolumella. Comparing these two modifications, i-epresentedby Fig. 85, a and h with c,—or, again, those of Fig. 86, aand h,—the interpretation seems to be that the fibro-vascularcord passin
The origin of floral structures through insect and other agencies . ssor Henslow described a monstrous con-dition of Mignonette with figures of ovules in this condition.*They were sometimesreplaced by minuteleaves (Fig. 85, c) ; orelse in the place ofeach was a cup-likestructure, elevatedon a long stalk, withan egg-like nucelluswithin, but quite freefrom it. He likenedit to the theca of amoss with its centralcolumella. Comparing these two modifications, i-epresentedby Fig. 85, a and h with c,—or, again, those of Fig. 86, aand h,—the interpretation seems to be that the fibro-vascularcord passing up the funicle of the ovule becomes a petiole,and its prolongation constitutes the mid-rib. The secundineand primine with intermediate tissue become the blade, asseen in the foliaceous states of ovules, and constitute the cup when they assume that form. A similar process, I think, quite explains the origin ofthe foliaceous processes of the stamen of JatropJia, repre-sented by Fig. 84. The entire stamen is, of course, really* Tra7iS. Camh. Phil. Soc, vol.
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectfertili, bookyear1888
