Power of Murcnicnt in Plants. 143 



Hence they crowded together as closely as possible. Nowhere 

 ■was this better seen than in Desmodium, where the rising of the 

 petioles, and the vertical position of the leaves, acted in the same 

 direction. Without this provision many plants exposed to a 

 clear sky on a frosty night would perish. As a rule, plants that 

 slept did not get a good night's rest unless they had been 

 exposed to an adequate temperature the day before, the degree 

 varying in nearly every case. The leaves of the French bean 

 slept better at midsummer than earlier. A violent wind would 

 sometimes keep species of arrow-root awake for two nights in 

 succession. Among the many plants whose leaves slept, he 

 mentioned the stitchwort, mallow, flax, wood-sorrel, balsam, 

 I'rojKcohDii, lupine, clovers, Lotus, acacias, M'istari((, milk-vetch, 

 and many other Lq/uininosa; ; evening primrose, passion-flower, 

 tobacco-plant, Puhjijimuw, goosefoot, spurge, and only one 

 Cryptogam, the pepperwort. With respect to the sleep of 

 floAvers, Mr. Worsley-Benison remarked that the " floral clock ' 

 of Linnfeus must not be taken literally, because a dull day or a 

 bright one, a dry morning or a moist one, would often modify 

 the accuracy of the statements. Still, certain flowers had in 

 many cases a pronounced tendency to open and close at specific 

 times, or within a few minutes of those times. He then referred 

 to the list made out by Linnaeus, which had been abbreviated 

 by De CandoUe, and confirmed as follows in each instance : — 

 Time of opening — 2 a.m., purple convolvulus; 3 to 4 a.m., great 

 bindweed; 5 a.m., chicory; 5 to 6 a.m., dandelion, nipple- 

 wort, and blue convolvulus ; 7 a.m., water lilies ; 8 a.m., 

 scarlet pimpernel; 9 a.m., marigold; 9 to 10 a.m., red sand- 

 wort; 11 a.m., star of bethlehem ; noon, blue passion flower; 

 2 p.m., Pi/rctJinun; 5 to 6 p.m., night-flowering catch-fly ; 6 p.m., 

 evening primrose; 7 j).m., evening campion; 7 to 8 p.m., 

 night-flowering Cereiis. Some flowers closed at certain hours ; 

 goatsbeard closed at noon, hence the name given to it of " John 

 Go-to-bed-at-noon." He had watched these plants on the banks 

 of the Wye, and had never seen a greater variation in the time 

 than between 11.45 a.m. and 12.15 p.m. The pimpernel closed 

 at 3 p.m., marigold between 4 and 5 p.m., yellow-wort at 5 p.m., 

 and the daisy towards sunset. Those flowers opening after 

 6 p.m. were night-flowering plants, and were all fragrant, to 

 attract the night-flying moths as their fertilisers. Some flowers, 

 such as the red sandwort, closed instantly on being plucked ; 

 others, once opened remained so till they Avithered, as did most 

 orchids ; others, like the commercial flax, closed a few hours 

 after expanding, never to open again. The water-lily remained 

 open for twelve hours ; purslane closed after an hour's expan- 

 sion at noon. All these movements depended on the intensity 

 of light. The mechanism of the movements Avas not so well 



