SLEEP OF FLOWERS.

Globe, Volume XXII, Issue 1831, 5 January 1880, Page 3

SLEEP OF FLOWERS.

I have elsewhere here suggested so-called “sleeo” of flowers have reference to the habits of insects, on the ground that flowers, which are fertilised by night-flying insects, would derive no advantage by being open in the day; wi ile, on the other hand, those which are fertilised by bees would gain nothing by being open at night. T confess that I suggested this with much diffidence, but it msy now, I think, bo regarded as wellestablished. “ Pilene nutans,” the Nottingham catchfly, ia a very instructive species from this pou t of view, and, indeed, illustrates a number of interesting points ia the relations between plants and insects. Its life history has recently been well described by Earner. 'lhe upper part cf the flowering stem is viscid, from which it has derived its local name—the Nottingham catcbfly. This prevents the access of ants and other small creeping insects. Snob flower lasts three days, or rather three nights. The stamens are ten in number, arranged in two sets, the one set standing in front of the serials, the other in front of the petals. Like other night flowers, it is white, and opens towards evening, when it also becomes extremely fragrant. The first evening, toward dusk, the"stamens in front of the sepal;. grow very rapidly for about two hours, so that they emerge from !hs flower; the pollen ripens, and ia exposed by the bursting of the ar. her. fio that tae flower remains through the night very attractive to, and much visited by moths. Toward throe in the morning the scent ceases, the anthers begin to shrivel up or drop off, the filaments turn tin mselvs outward so as to be out of the way, while the pet ds, ou the con'rary, begin to roll tbemselv- s up, to that i-y daylight they close the aperture of the flower, and present only their brownish green under sides to

view, which, moreover, are thrown into numerous wrinkles. Thus, by the morning’s light, the flower has all the appearance of being faded. It has no smell, and the honey is covered ever by the petale. So it remains all day. Toward evening, however, everything is changed. The petals unfold themselves, by eigne o'clock the flower is as fragrant as before, the second set of stamens have rapidly grown, their anthers are open, and the pollen again exposed. By morning the plant is again asleep, the anthers are shriveled, the scent has ceased, and the petals rolled up as before. The third evening again the same process, but this time it is the pistil which grows, and the long spiral stigmas on the third evening take the position which on the previous two bad been occupied by the anthers, and can hardly fail to be dusted >y the moths with pollen brought from another flower. An objection to the view that the sleep of flowers is regulated by the visits of insects might b.! derived from the cases of those flowcie which close early in the day. the well-known “ Tragopogon pratense,” or “ John Go-to-Bed at Noon,” for instance ; still more, suth species as “ Lacoena communis,” or 11 Crepii pulchra,” which open before six and clrse again before ten in the morning Bess, however, are very early risers, while ants come out much later, when the dew is off the grass; so that it might well be an advantage to a flower that was quite unprotected to open early for the bees, and close again before the ants wore out, thus preserving its honey for another day —Sir John Lubbock in the “ Fortnightly Review.”